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2. Outcomes and Conclusions from the 2018 AM-Bench Measurements, Challenge Problems, Modeling Submissions, and Conference

Author

Levine, L, Lane, B, Heigel, J, Migler, K, Stoudt, M, Phan, T, Ricker, R, Strantza, M, Hill, M, Zhang, F, Seppala, J, Garboczi, E, Bain, E, Cole, D, Allen, A, Fox, J, and Campbell, C

Subjects
Additive manufacturing, Benchmarks, Model validation, AM-Bench
Abstract

The Additive Manufacturing Benchmark (AM-Bench) test series was established to provide rigorous measurement test data for validating additive manufacturing (AM) simulations for a broad range of AM technologies and material systems. AM-Bench includes extensive in situ and ex situ measurements, simulation challenges for the AM modeling community, and a corresponding conference series. In 2018, the first round of AM-Bench measurements and the first AM-Bench conference were completed, focusing primarily upon laser powder bed fusion (LPBF) processing of metals, and both LPBF and material extrusion processing of polymers. In all, 46 blind modeling simulations were submitted by the international AM community in comparison with the in situ and ex situ measurements. Analysis of these submissions provides valuable insight into existing AM modeling capabilities. The AM-Bench data are permanently archived and freely accessible online.

Published
2020

4. Wind redistribution of snow impacts the Ka- and Ku-band radar signatures of Arctic sea ice

Author

Nandan, V., Willatt, R., Mallett, R., Stroeve, J., Geldsetzer, T., Scharien, R., Tonboe, R., Yackel, J., Landy, J., Clemens-Sewall, D., Jutila, A., Wagner, D. N., Krampe, D., Huntemann, M., Mahmud, M., Jensen, D., Newman, T., Hendricks, S., Spreen, G., Macfarlane, A., Schneebeli, M., Mead, J., Ricker, R., Gallagher, M., Duguay, C., Raphael, I., Polashenski, C., Tsamados, M., Matero, I., and Hoppmann, M.

Subjects
SDG 13 - Climate Action
Abstract

Wind-driven redistribution of snow on sea ice alters its topography and microstructure, yet the impact of these processes on radar signatures is poorly understood. Here, we examine the effects of snow redistribution over Arctic sea ice on radar waveforms and backscatter signatures obtained from a surface-based, fully polarimetric Ka- and Ku-band radar at incidence angles between 0∘ (nadir) and 50∘. Two wind events in November 2019 during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition are evaluated. During both events, changes in Ka- and Ku-band radar waveforms and backscatter coefficients at nadir are observed, coincident with surface topography changes measured by a terrestrial laser scanner. At both frequencies, redistribution caused snow densification at the surface and the uppermost layers, increasing the scattering at the air–snow interface at nadir and its prevalence as the dominant radar scattering surface. The waveform data also detected the presence of previous air–snow interfaces, buried beneath newly deposited snow. The additional scattering from previous air–snow interfaces could therefore affect the range retrieved from Ka- and Ku-band satellite altimeters. With increasing incidence angles, the relative scattering contribution of the air–snow interface decreases, and the snow–sea ice interface scattering increases. Relative to pre-wind event conditions, azimuthally averaged backscatter at nadir during the wind events increases by up to 8 dB (Ka-band) and 5 dB (Ku-band). Results show substantial backscatter variability within the scan area at all incidence angles and polarizations, in response to increasing wind speed and changes in wind direction. Our results show that snow redistribution and wind compaction need to be accounted for to interpret airborne and satellite radar measurements of snow-covered sea ice.

Published
2023

5. Retrieval of Snow Depth on Arctic Sea Ice From Surface-Based, Polarimetric, Dual-Frequency Radar Altimetry

Author

Willatt, R., Stroeve, J.C., Nandan, V., Newman, T., Mallett, R., Hendricks, S., Ricker, R., Mead, J., Itkin, P., Tonboe, R., Wagner, D.N., Spreen, G., Liston, G., Schneebeli, M., Krampe, D., Tsamados, M., Demir, O., Wilkinson, J., Jaggi, M., Zhou, L., Huntermann, M., Raphael, I.A., Jutila, A., Oggier, M., Willatt, R., Stroeve, J.C., Nandan, V., Newman, T., Mallett, R., Hendricks, S., Ricker, R., Mead, J., Itkin, P., Tonboe, R., Wagner, D.N., Spreen, G., Liston, G., Schneebeli, M., Krampe, D., Tsamados, M., Demir, O., Wilkinson, J., Jaggi, M., Zhou, L., Huntermann, M., Raphael, I.A., Jutila, A., and Oggier, M.

Abstract

Snow depth on sea ice is an Essential Climate Variable and a major source of uncertainty in satellite altimetry-derived sea ice thickness. During winter of the MOSAiC Expedition, the “KuKa” dual-frequency, fully polarized Ku- and Ka-band radar was deployed in “stare” nadir-looking mode to investigate the possibility of combining these two frequencies to retrieve snow depth. Three approaches were investigated: dual-frequency, dual-polarization and waveform shape, and compared to independent snow depth measurements. Novel dual-polarization approaches yielded r2 values up to 0.77. Mean snow depths agreed within 1 cm, even for data sub-banded to CryoSat-2 SIRAL and SARAL AltiKa bandwidths. Snow depths from co-polarized dual-frequency approaches were at least a factor of four too small and had a r2 0.15 or lower. r2 for waveform shape techniques reached 0.72 but depths were underestimated. Snow depth retrievals using polarimetric information or waveform shape may therefore be possible from airborne/satellite radar altimeters.

Published
2023

6. Linking scales of sea ice surface topography: evaluation of ICESat-2 measurements with coincident helicopter laser scanning during MOSAiC

Author

Ricker, R., Fons, S., Jutila, A., Hutter, N., Duncan, K., Farrell, S. L., Kurtz, N. T., Fredensborg Hansen, R. M., Ricker, R., Fons, S., Jutila, A., Hutter, N., Duncan, K., Farrell, S. L., Kurtz, N. T., and Fredensborg Hansen, R. M.

Abstract

Information about sea ice surface topography and related deformation is crucial for studies of sea ice mass balance, sea ice modeling, and ship navigation through the ice pack. The Ice, Cloud, and land Elevation Satellite-2 (ICESat-2), part of the National Aeronautics and Space Administration (NASA) Earth Observing System, has been on orbit for over 4 years, sensing the sea ice surface topography with six laser beams capable of capturing individual features such as pressure ridges. To assess the capabilities and uncertainties of ICESat-2 products, coincident high-resolution measurements of sea ice surface topography are required. During the yearlong Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition in the Arctic Ocean, we successfully carried out a coincident underflight of ICESat-2 with a helicopter-based airborne laser scanner (ALS), achieving an overlap of more than 100 km. Despite the comparably short data set, the high-resolution centimeter-scale measurements of the ALS can be used to evaluate the performance of ICESat-2 products. Our goal is to investigate how the sea ice surface roughness and topography are represented in different ICESat-2 products as well as how sensitive ICESat-2 products are to leads and small cracks in the ice cover. Here, we compare the ALS measurements with ICESat-2's primary sea ice height product, ATL07, and the high-fidelity surface elevation product developed by the University of Maryland (UMD). By applying a ridge-detection algorithm, we find that 16 % (4 %) of the number of obstacles in the ALS data set are found using the strong (weak) center beam in ATL07. Significantly higher detection rates of 42 % (30 %) are achieved when using the UMD product. While only one lead is indicated in ATL07 for the underflight, the ALS reveals many small, narrow, and only partly open cracks that appear to be overlooked by ATL07.

Published
2023

8. Rain on snow (ROS) understudied in sea ice remote sensing: a multi-sensor analysis of ROS during MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate)

Author

Stroeve, J., Nandan, V., Willatt, R., Dadic, R., Rotosky, P., Gallagher, M., Mallett, R., Barrett, A., Hendricks, S., Tonboe, R., Serreze, M., Thielke, L., Spreen, G., Newman, T., Yackel, J., Ricker, R., Tsamados, M., Macfarlane, A., Hannula, H.-R., Schneebeli, M., Stroeve, J., Nandan, V., Willatt, R., Dadic, R., Rotosky, P., Gallagher, M., Mallett, R., Barrett, A., Hendricks, S., Tonboe, R., Serreze, M., Thielke, L., Spreen, G., Newman, T., Yackel, J., Ricker, R., Tsamados, M., Macfarlane, A., Hannula, H.-R., and Schneebeli, M.

Abstract

Arctic rain on snow (ROS) deposits liquid water onto existing snowpacks. Upon refreezing, this can form icy crusts at the surface or within the snowpack. By altering radar backscatter and microwave emissivity, ROS over sea ice can influence the accuracy of sea ice variables retrieved from satellite radar altimetry, scatterometers, and passive microwave radiometers. During the Arctic Ocean MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) expedition, there was an unprecedented opportunity to observe a ROS event using in situ active and passive microwave instruments similar to those deployed on satellite platforms. During liquid water accumulation in the snowpack from rain and increased melt, there was a 4-fold decrease in radar energy returned at Ku- and Ka-bands. After the snowpack refroze and ice layers formed, this decrease was followed by a 6-fold increase in returned energy. Besides altering the radar backscatter, analysis of the returned waveforms shows the waveform shape changed in response to rain and refreezing. Microwave emissivity at 19 and 89 GHz increased with increasing liquid water content and decreased as the snowpack refroze, yet subsequent ice layers altered the polarization difference. Corresponding analysis of the CryoSat-2 waveform shape and backscatter as well as AMSR2 brightness temperatures further shows that the rain and refreeze were significant enough to impact satellite returns. Our analysis provides the first detailed in situ analysis of the impacts of ROS and subsequent refreezing on both active and passive microwave observations, providing important baseline knowledge for detecting ROS over sea ice and assessing their impacts on satellite-derived sea ice variables.

Published
2022

9. Geodetic GNSS data for atmospheric sounding recorded during the MOSAiC Expedition 2019-2020

Author

Männel, B., Bradke, M., Semmling, M., Wickert, J., Gerber, T., Magnussen, S., Spreen, G., Ricker, R., Kaleschke, L., and Tavri, A.

Abstract

During the transpolar drifting campaign MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) of RV Polarstern (AWI, 2017), GNSS was used among other techniques to monitor variations in atmospheric water vapor. This dataset comprises the RINEX data tracked by a top-side GNSS antenna installed at the compass deck of RV Polarstern. The GNSS equipment was installed on July 4th, 2019. For logistical reasons, the receiver was switched off on October 3rd at a position very close to Ny Ålesund, Svalbard. According to the MOSAiC data guidelines, data for the following periods are not provided in this dataset: - September 12-26, 2019 - June 3-8, 2020 - October 2-3, 2020

Published
2021

10. The CARMENES search for exoplanets around M dwarfs

Author

S. Dreizler, I. J. M. Crossfield, D. Kossakowski, P. Plavchan, S. V. Jeffers, J. Kemmer, R. Luque, N. Espinoza, E. Pallé, K. Stassun, E. Matthews, B. Cale, J. A. Caballero, M. Schlecker, J. Lillo-Box, M. Zechmeister, S. Lalitha, A. Reiners, A. Soubkiou, B. Bitsch, M. R. Zapatero Osorio, P. Chaturvedi, A. P. Hatzes, G. Ricker, R. Vanderspek, D. W. Latham, S. Seager, J. Winn, J. M. Jenkins, J. Acei

Published
2020
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11. Arctic Report Card 2020: Sea Ice

Author

Perovich, Donald, Meier, W., Tschudi, M., Hendricks, S., Petty, A. A., Divine, D., Farrell, S., Gerland, S., Haas, C., Kaleschke, L., Pavlova, O., Ricker, R., Tian-Kunze, X., Wood, K., and Webster, M.

Abstract

Arctic Report Card

Published
2020
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12. Broadband mid-infrared superlattice light-emitting diodes.

Author

Ricker, R. J., Provence, S. R., Norton, D. T., Boggess Jr., T. F., and Prineas, J. P.

Subjects
*LIGHT emitting diodes, *BAND gaps, *BROADBAND communication systems, *BANDWIDTHS, *WAVELENGTHS
Abstract

InAs/GaSb type-II superlattice light-emitting diodes were fabricated to form a device that provides emission over the entire 3-5 μm mid-infrared transmission window. Variable bandgap emission regions were coupled together using tunnel junctions to emit at peak wavelengths of 3.3 μm, 3.5 μm, 3.7 μm, 3.9 μm, 4.1 μm, 4.4 μm, 4.7 μm, and 5.0 μm. Cascading the structure recycles the electrons in each emission region to emit several wavelengths simultaneously. At high current densities, the light-emitting diode spectra broadened into a continuous, broadband spectrum that covered the entire mid-infrared band. When cooled to 77 K, radiances of over 1W/cm2 sr were achieved, demonstrating apparent temperatures above 1000K over the 3-5 μm band. InAs/GaSb type-II superlattices are capable of emitting from 3 μm to 30μm, and the device design can be expanded to include longer emission wavelengths. [ABSTRACT FROM AUTHOR]

Published
2017
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14. Copernicus Marine Service Ocean state report, Issue 3 Introduction

Author

von Schuckmann, K., Le Traon, P. Y., Smith, N., Pascual, A., Djavidnia, S., Gattuso, J. P., Gregoire, M., Nolan, G., Aaboe, S., Aguiar, E., Fanjul, E. A., Alvera-Azcarate, A., Aouf, L., Barciela, R., Behrens, A., Rivas, M. B., Ismail, S. B., Bentamy, A., Borgini, M., Brando, V. E., Bensoussan, N., Blauw, A., Bryere, P., Nardelli, B. B., Caballero, A., Yumruktepe, V. C., Cebrian, E., Chiggiato, J., Clementi, E., Corgnati, L., de Alfonso, M., Collar, A. D., Deshayes, J., Di Lorenzo, E., Dominici, J. M., Dupouy, Cécile, Drevillon, M., Echevin, Vincent, Eleveld, M., Enserink, L., Sotillo, M. G., Garnesson, P., Garrabou, J., Garric, G., Gasparin, F., Gayer, G., Gohin, F., Grandi, A., Griffa, A., Gourrion, J., Hendricks, S., Heuze, C., Holland, E., Iovino, D., Juza, M., Kersting, D. K., Kipson, S., Kizilkaya, Z., Korres, G., Kouts, M., Lagemaa, P., Lavergne, T., Lavigne, H., Ledoux, J. B., Legeais, J. F., Lehodey, P., Linares, C., Liu, Y., Mader, J., Maljutenko, I., Mangin, A., Manso-Narvarte, I., Mantovani, C., Markager, S., Mason, E., Mignot, A., Menna, M., Monier, M., Mourre, B., Muller, M., Nielsen, J. W., Notarstefano, G., Ocana, O., Patti, B., Payne, M. R., Peirache, M., Pardo, S., Perez Gomez, B., Pisano, A., Perruche, C., Peterson, K. A., Pujol, M. I., Raudsepp, U., Ravdas, M., Raj, R. P., Renshaw, R., Reyes, E., Ricker, R., Rubio, A., Sammartino, M., Santoleri, R., Sathyendranath, S., Schroeder, K., She, J., Sparnocchia, S., Staneva, J., Stoffelen, A., Szekely, T., Tilstone, G. H., Tinker, J., Tintore, J., Tranchant, B., Uiboupin, R., Van der Zande, D., Wood, R., Zabala, M., Zacharioudaki, A., Zuberer, F., and Zuo, H.

Published
2019

15. State of the Climate in 2018

Author

Arndt, D. S., Blunden, J., Dunn, R. J. H., Stanitski, D. M., Gobron, N., Willett, K. M., Sanchez-lugo, A., Berrisford, P., Morice, C., Nicolas, Jp, Carrea, L., Woolway, R. I., Merchant, C. J., Dokulil, M. T., De Eyto, E., Degasperi, C. L., Korhonen, J., Marszelewski, W., May, L., Paterson, A. M., Rusak, J. A., Schladow, S. G., Schmid, M., Verburg, P., Watanabe, S., Weyhenmeyer, G. A., King, A. D., Donat, M. G., Christy, J. R., Po-chedley, S., Mears, C. R., Haimberger, L., Covey, C., Randel, W., Noetzli, J., Biskaborn, B. K., Christiansen, H. H., Isaksen, K., Schoeneich, P., Smith, S., Vieira, G., Zhao, L., Streletskiy, D. A., Robinson, D. A., Pelto, M., Berry, D. I., Bosilovich, M. G., Simmons, A. J., Mears, C., Ho, S. P., Bock, O., Zhou, X., Nicolas, J, Vose, R. S., Adler, R., Gu, G., Becker, A., Yin, X, Tye, M. R., Blenkinsop, S., Durre, I., Ziese, M., Collow, A. B. Marquardt, Rustemeier, E., Foster, M. J., Di Girolamo, L., Frey, R. A., Heidinger, A. K., Sun-mack, S., Phillips, C., Menzel, W. P., Stengel, M., Zhao, G., Kim, H., Rodell, M., Li, B., Famiglietti, J. S., Scanlon, T., Van Der Schalie, R., Preimesberger, W., Reimer, C., Hahn, S., Gruber, A., Kidd, R., De Jeu, R. A. M., Dorigo, W. A., Barichivich, J., Osborn, T. J., Harris, I., Van Der Schrier, G., Jones, P. D., Miralles, D. G., Martens, B., Beck, H. E., Dolman, A. J., Jimenez, C., Mccabe, M. F., Wood, E. F., Allan, R., Azorin-molina, C., Mears, C. A., Mcvicar, T. R., Mayer, M., Schenzinger, V., Hersbach, H., Stackhouse, P. W., Jr., Wong, T., Kratz, D. P., Sawaengphokhai, P., Wilber, A. C., Gupta, S. K., Loeb, N. G., Dlugokencky, E. J., Hall, B. D., Montzka, S. A., Dutton, G., Muhle, J., Elkins, J. W., Miller, Br, Remy, S., Bellouin, N., Kipling, Z., Ades, M., Benedetti, A., Boucher, O., Weber, M., Steinbrecht, W., Arosio, C., Van Der A, R., Frith, S. M., Anderson, J., Coldewey-egbers, M., Davis, S., Degenstein, D., Fioletov, V. E., Froidevaux, L., Hubert, D., Long, C. S., Loyola, D., Rozanov, A., Roth, C., Sofieva, V., Tourpali, K., Wang, R., Wild, J. D., Davis, S. M., Rosenlof, K. H., Hurst, D. F., Selkirk, H. B., Vomel, H., Ziemke, J. R., Cooper, O. R., Flemming, J., Inness, A., Pinty, B., Kaiser, J. W., Van Der Werf, G. R., Hemming, D. L., Garforth, J., Park, T., Richardson, A. D., Rutishauser, T., Sparks, T. H., Thackeray, S. J., Myneni, R., Lumpkin, R., Huang, B., Kennedy, J., Xue, Y., Zhang, H. -m., Hu, C., Wang, M., Johnson, G. C., Lyman, J. M., Boyer, T., Cheng, L., Domingues, C. M., Gilson, J., Ishii, M., Killick, R. E., Monselesan, D., Purkey, S. G., Wijffels, S. E., Locarnini, R., Yu, L., Jin, X., Stackhouse, P. W., Kato, S., Weller, R. A., Thompson, P. R., Widlansky, M. J., Leuliette, E., Sweet, W., Chambers, D. P., Hamlington, B. D., Jevrejeva, S., Marra, J. J., Merrifield, M. A., Mitchum, G. T., Nerem, R. S., Kelble, C., Karnauskas, M., Hubbard, K., Goni, G., Streeter, C., Dohan, K., Franz, B. A., Cetinic, I., Karakoylu, E. M., Siegel, D. A., Westberry, T. K., Feely, R. A., Wanninkhof, R., Carter, B. R., Landschutzer, P., Sutton, A. J., Cosca, C., Trinanes, J. A., Baxter, S., Schreck, C., Bell, G. D., Mullan, A. B., Pezza, A. B., Coelho, C. A. S., Wang, B., He, Q., Diamond, H. J., Schreck, C. J., Blake, E. S., Landsea, C. W., Wang, H., Goldenberg, S. B., Pasch, R. J., Klotzbach, P. J., Kruk, M. C., Camargo, S. J., Trewin, B. C., Pearce, P. R., Lorrey, A. M., Domingues, R., Goni, G. J., Knaff, J. A., Lin, I. -i., Bringas, F., Richter-menge, J., Osborne, E., Druckenmiller, M., Jeffries, M. O., Overland, J. E., Hanna, E., Hanssen-bauer, I., Kim, S. -j., Walsh, J. E., Bhatt, U. S., Timmermans, M. -l., Ladd, C., Perovich, D., Meier, W., Tschudi, M., Farrell, S., Hendricks, S., Gerland, S., Haas, C., Krumpen, T., Polashenski, C., Ricker, R, Webster, M., Stabeno, P. J., Tedesco, M., Box, J. E., Cappelen, J., Fausto, R. S., Fettweis, X., Andersen, J. K., Mote, T., Smeets, C. J. P. P., Van As, D., Van De Wal, R. S. W., Romanovsky, V. E., Smith, S. L., Shiklomanov, N. I., Kholodov, A. L., Drozdov, D. S., Malkova, G. V., Marchenko, S. S., Jella, K. B., Mudryk, L., Brown, R., Derksen, C., Luojus, K., Decharme, B., Holmes, R. M., Shiklomanov, A. I., Suslova, A., Tretiakov, M., Mcclelland, J. W., Spencer, R. G. M., Tank, S. E., Epstein, H., Bhatt, U., Raynolds, M., Walker, D., Forbes, B., Phoenix, G., Bjerke, J., Tommervik, H., Karlsen, S. -r., Goetz, S., Jia, G., Bernhard, G. H., Grooss, J. -u., Ialongo, I., Johnsen, B., Lakkala, K., Manney, G. L., Mueller, R., Scambos, T., Stammerjohn, S., Clem, K. R., Barreira, S., Fogt, R. L., Colwell, S., Keller, L. M., Lazzara, M. A., Reid, P., Massom, R. A., Lieser, J. L., Meijers, A., Sallee, J. -b., Grey, A., Johnson, K., Arrigo, K., Swart, S., King, B., Meredith, M., Mazloff, M., Scardilli, A., Claus, F., Shuman, C. A., Kramarova, N., Newman, P. A., Nash, E. R., Strahan, S. E., Johnson, B., Pitts, M., Santee, M. L., Petropavlovskikh, I., Braathen, G. O., Coy, L., De Laat, J., Bissolli, P., Ganter, C., Li, T., Mekonnen, A., Gleason, K., Smith, A., Fenimore, C., Heim, R. R., Jr., Nauslar, N. J., Brown, T. J., Mcevoy, D. J., Lareau, N. P., Amador, J. A., Hidalgo, H. G., Alfaro, E. J., Calderon, B., Mora, N., Stephenson, T. S., Taylor, M. A., Trotman, A. R., Van Meerbeeck, C. J., Campbell, J. D., Brown, A., Spence, J., Martinez, R., Diaz, E., Marin, D., Hernandez, R., Caceres, L., Zambrano, E., Nieto, J., Marengo, J. A., Espinoza, J. C., Alves, L. M., Ronchail, J., Lavado-casimiro, J. W., Ramos, I., Davila, C., Ramos, A. M., Diniz, F. A., Aliaga-nestares, V., Castro, A. Y., Stella, J. L., Aldeco, L. S., Diaz, D. A. Campos, Misevicius, N., Kabidi, K., Sayouri, A., Elkharrim, M., Mostafa, A. E., Hagos, S., Feng, Z., Ijampy, J. A., Sima, F., Francis, S. D., Tsidu, G. Mengistu, Kruger, A. C., Mcbride, C., Jumaux, G., Dhurmea, K. R., Belmont, M., Rakotoarimalala, C. L., Labbe, L., Rosner, B., Benedict, I., Van Heerwaarden, C., Weerts, A., Hazeleger, W., Trachte, K., Zhu, Z., Zhang, P., Lee, T. C., Ripaldi, A., Mochizuki, Y., Lim, J. -y, Oyunjargal, L., Timbal, B., Srivastava, A. K., Revadekar, J. V., Rajeevan, M., Shimpo, A., Khoshkam, M., Kazemi, A. Fazl, Zeyaeyan, S., Lander, M. A., Mcgree, S., Tobin, S., Bettio, L., Arndt, D. S., Blunden, J., Dunn, R. J. H., Stanitski, D. M., Gobron, N., Willett, K. M., Sanchez-lugo, A., Berrisford, P., Morice, C., Nicolas, Jp, Carrea, L., Woolway, R. I., Merchant, C. J., Dokulil, M. T., De Eyto, E., Degasperi, C. L., Korhonen, J., Marszelewski, W., May, L., Paterson, A. M., Rusak, J. A., Schladow, S. G., Schmid, M., Verburg, P., Watanabe, S., Weyhenmeyer, G. A., King, A. D., Donat, M. G., Christy, J. R., Po-chedley, S., Mears, C. R., Haimberger, L., Covey, C., Randel, W., Noetzli, J., Biskaborn, B. K., Christiansen, H. H., Isaksen, K., Schoeneich, P., Smith, S., Vieira, G., Zhao, L., Streletskiy, D. A., Robinson, D. A., Pelto, M., Berry, D. I., Bosilovich, M. G., Simmons, A. J., Mears, C., Ho, S. P., Bock, O., Zhou, X., Nicolas, J, Vose, R. S., Adler, R., Gu, G., Becker, A., Yin, X, Tye, M. R., Blenkinsop, S., Durre, I., Ziese, M., Collow, A. B. Marquardt, Rustemeier, E., Foster, M. J., Di Girolamo, L., Frey, R. A., Heidinger, A. K., Sun-mack, S., Phillips, C., Menzel, W. P., Stengel, M., Zhao, G., Kim, H., Rodell, M., Li, B., Famiglietti, J. S., Scanlon, T., Van Der Schalie, R., Preimesberger, W., Reimer, C., Hahn, S., Gruber, A., Kidd, R., De Jeu, R. A. M., Dorigo, W. A., Barichivich, J., Osborn, T. J., Harris, I., Van Der Schrier, G., Jones, P. D., Miralles, D. G., Martens, B., Beck, H. E., Dolman, A. J., Jimenez, C., Mccabe, M. F., Wood, E. F., Allan, R., Azorin-molina, C., Mears, C. A., Mcvicar, T. R., Mayer, M., Schenzinger, V., Hersbach, H., Stackhouse, P. W., Jr., Wong, T., Kratz, D. P., Sawaengphokhai, P., Wilber, A. C., Gupta, S. K., Loeb, N. G., Dlugokencky, E. J., Hall, B. D., Montzka, S. A., Dutton, G., Muhle, J., Elkins, J. W., Miller, Br, Remy, S., Bellouin, N., Kipling, Z., Ades, M., Benedetti, A., Boucher, O., Weber, M., Steinbrecht, W., Arosio, C., Van Der A, R., Frith, S. M., Anderson, J., Coldewey-egbers, M., Davis, S., Degenstein, D., Fioletov, V. E., Froidevaux, L., Hubert, D., Long, C. S., Loyola, D., Rozanov, A., Roth, C., Sofieva, V., Tourpali, K., Wang, R., Wild, J. D., Davis, S. M., Rosenlof, K. H., Hurst, D. F., Selkirk, H. B., Vomel, H., Ziemke, J. R., Cooper, O. R., Flemming, J., Inness, A., Pinty, B., Kaiser, J. W., Van Der Werf, G. R., Hemming, D. L., Garforth, J., Park, T., Richardson, A. D., Rutishauser, T., Sparks, T. H., Thackeray, S. J., Myneni, R., Lumpkin, R., Huang, B., Kennedy, J., Xue, Y., Zhang, H. -m., Hu, C., Wang, M., Johnson, G. C., Lyman, J. M., Boyer, T., Cheng, L., Domingues, C. M., Gilson, J., Ishii, M., Killick, R. E., Monselesan, D., Purkey, S. G., Wijffels, S. E., Locarnini, R., Yu, L., Jin, X., Stackhouse, P. W., Kato, S., Weller, R. A., Thompson, P. R., Widlansky, M. J., Leuliette, E., Sweet, W., Chambers, D. P., Hamlington, B. D., Jevrejeva, S., Marra, J. J., Merrifield, M. A., Mitchum, G. T., Nerem, R. S., Kelble, C., Karnauskas, M., Hubbard, K., Goni, G., Streeter, C., Dohan, K., Franz, B. A., Cetinic, I., Karakoylu, E. M., Siegel, D. A., Westberry, T. K., Feely, R. A., Wanninkhof, R., Carter, B. R., Landschutzer, P., Sutton, A. J., Cosca, C., Trinanes, J. A., Baxter, S., Schreck, C., Bell, G. D., Mullan, A. B., Pezza, A. B., Coelho, C. A. S., Wang, B., He, Q., Diamond, H. J., Schreck, C. J., Blake, E. S., Landsea, C. W., Wang, H., Goldenberg, S. B., Pasch, R. J., Klotzbach, P. J., Kruk, M. C., Camargo, S. J., Trewin, B. C., Pearce, P. R., Lorrey, A. M., Domingues, R., Goni, G. J., Knaff, J. A., Lin, I. -i., Bringas, F., Richter-menge, J., Osborne, E., Druckenmiller, M., Jeffries, M. O., Overland, J. E., Hanna, E., Hanssen-bauer, I., Kim, S. -j., Walsh, J. E., Bhatt, U. S., Timmermans, M. -l., Ladd, C., Perovich, D., Meier, W., Tschudi, M., Farrell, S., Hendricks, S., Gerland, S., Haas, C., Krumpen, T., Polashenski, C., Ricker, R, Webster, M., Stabeno, P. J., Tedesco, M., Box, J. E., Cappelen, J., Fausto, R. S., Fettweis, X., Andersen, J. K., Mote, T., Smeets, C. J. P. P., Van As, D., Van De Wal, R. S. W., Romanovsky, V. E., Smith, S. L., Shiklomanov, N. I., Kholodov, A. L., Drozdov, D. S., Malkova, G. V., Marchenko, S. S., Jella, K. B., Mudryk, L., Brown, R., Derksen, C., Luojus, K., Decharme, B., Holmes, R. M., Shiklomanov, A. I., Suslova, A., Tretiakov, M., Mcclelland, J. W., Spencer, R. G. M., Tank, S. E., Epstein, H., Bhatt, U., Raynolds, M., Walker, D., Forbes, B., Phoenix, G., Bjerke, J., Tommervik, H., Karlsen, S. -r., Goetz, S., Jia, G., Bernhard, G. H., Grooss, J. -u., Ialongo, I., Johnsen, B., Lakkala, K., Manney, G. L., Mueller, R., Scambos, T., Stammerjohn, S., Clem, K. R., Barreira, S., Fogt, R. L., Colwell, S., Keller, L. M., Lazzara, M. A., Reid, P., Massom, R. A., Lieser, J. L., Meijers, A., Sallee, J. -b., Grey, A., Johnson, K., Arrigo, K., Swart, S., King, B., Meredith, M., Mazloff, M., Scardilli, A., Claus, F., Shuman, C. A., Kramarova, N., Newman, P. A., Nash, E. R., Strahan, S. E., Johnson, B., Pitts, M., Santee, M. L., Petropavlovskikh, I., Braathen, G. O., Coy, L., De Laat, J., Bissolli, P., Ganter, C., Li, T., Mekonnen, A., Gleason, K., Smith, A., Fenimore, C., Heim, R. R., Jr., Nauslar, N. J., Brown, T. J., Mcevoy, D. J., Lareau, N. P., Amador, J. A., Hidalgo, H. G., Alfaro, E. J., Calderon, B., Mora, N., Stephenson, T. S., Taylor, M. A., Trotman, A. R., Van Meerbeeck, C. J., Campbell, J. D., Brown, A., Spence, J., Martinez, R., Diaz, E., Marin, D., Hernandez, R., Caceres, L., Zambrano, E., Nieto, J., Marengo, J. A., Espinoza, J. C., Alves, L. M., Ronchail, J., Lavado-casimiro, J. W., Ramos, I., Davila, C., Ramos, A. M., Diniz, F. A., Aliaga-nestares, V., Castro, A. Y., Stella, J. L., Aldeco, L. S., Diaz, D. A. Campos, Misevicius, N., Kabidi, K., Sayouri, A., Elkharrim, M., Mostafa, A. E., Hagos, S., Feng, Z., Ijampy, J. A., Sima, F., Francis, S. D., Tsidu, G. Mengistu, Kruger, A. C., Mcbride, C., Jumaux, G., Dhurmea, K. R., Belmont, M., Rakotoarimalala, C. L., Labbe, L., Rosner, B., Benedict, I., Van Heerwaarden, C., Weerts, A., Hazeleger, W., Trachte, K., Zhu, Z., Zhang, P., Lee, T. C., Ripaldi, A., Mochizuki, Y., Lim, J. -y, Oyunjargal, L., Timbal, B., Srivastava, A. K., Revadekar, J. V., Rajeevan, M., Shimpo, A., Khoshkam, M., Kazemi, A. Fazl, Zeyaeyan, S., Lander, M. A., Mcgree, S., Tobin, S., and Bettio, L.

Published
2019

18. High power cascaded mid-infrared InAs/GaSb light emitting diodes on mismatched GaAs.

Author

Provence, S. R., Ricker, R., Aytac, Y., Boggess, T. F., and Prineas, J. P.

Subjects
*OPTICAL properties of indium arsenide, *SUPERLATTICES, *LIGHT emitting diodes, *OPTICAL properties of gallium arsenide, *OPTICAL properties, *THERMAL properties, *MATHEMATICAL models
Abstract

InAs/GaSb mid-wave, cascaded superlattice light emitting diodes are found to give higher radiance when epitaxially grown on mismatched GaAs substrates compared to lattice-matched GaSb substrates. Peak radiances of 0.69 W/cm2-sr and 1.06 W/cm2-sr for the 100×100 µm2 GaSb and GaAs-based devices, respectively, were measured at 77 K. Measurement of the recombination coefficients shows the shorter Shockley-Read-Hall recombination lifetime as misfit dislocations for growth on GaAs degrade the quantum efficiency only at low current injection. The improved performance on GaAs was found to be due to the higher transparency and improved thermal properties of the GaAs substrate. [ABSTRACT FROM AUTHOR]

Published
2015
Full Text
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19. State of the climate in 2017

Author

Abernethy, R., Ackerman, Steven A., Adler, R., Albanil Encarnación, Adelina, Aldeco, Laura S., Alfaro, Eric J., Aliaga-Nestares, Vannia, Allan, Richard P., Allan, Rob, Alves, Lincoln M., Amador, Jorge A., Anderson, John, Andreassen, L. M., Argüez, Anthony, Armitage, C., Arndt, Derek S., Avalos, Grinia, Azorin-Molina, César, Báez, Julián, Bardin, M. Yu, Barichivich, Jonathan, Baringer, Molly O., Barreira, Sandra, Baxter, Stephen, Beck, H. E., Becker, Andreas, Bedka, Kristopher M., Behe, Carolina, Bell, Gerald D., Bellouin, Nicolas, Belmont, M., Benedetti, Angela, Bernhard, G. H., Berrisford, Paul, Berry, David I., Bhatt, U. S., Bissolli, Peter, Bjerke, J., Blake, Eric S., Blenkinsop, Stephen, Blunden, Jessica, Bolmgren, K., Bosilovich, Michael G., Boucher, Olivier, Bouchon, Marilú, Box, J. E., Boyer, Tim, Braathen, Geir O., Bromwich, David H., Brown, R., Buehler, S., Bulygina, Olga N., Burgess, D., Calderón, Blanca, Camargo, Suzana J., Campbell, Ethan C., Campbell, Jayaka D., Cappelen, J., Carrea, Laura, Carter, Brendan R., Castro, Anabel, Chambers, Don P., Cheng, Lijing, Christiansen, Hanne H., Christy, John R., Chung, E. S., Clem, Kyle R., Coelho, Caio A.S., Coldewey-Egbers, Melanie, Colwell, Steve, Cooper, Owen R., Copland, L., Costanza, Carol, Covey, Curt, Coy, Lawrence, Cronin, T., Crouch, Jake, Cruzado, Luis, Daniel, Raychelle, Davis, Sean M., Davletshin, S. G., De Eyto, Elvira, De Jeu, Richard A.M., De La Cour, Jacqueline L., De Laat, Jos, De Gasperi, Curtis L., Degenstein, Doug, Deline, P., Demircan, Mesut, Derksen, C., Dewitte, Boris, Dhurmea, R., Di Girolamo, Larry, Diamond, Howard J., Dickerson, C., Dlugokencky, Ed J., Dohan, Kathleen, Dokulil, Martin T., Dolman, A. Johannes, Domingues, Catia M., Domingues, Ricardo, Donat, Markus G., Dong, Shenfu, Dorigo, Wouter A., Drozdov, D. S., Dunn, Robert J.H., Durre, Imke, Dutton, Geoff S., Eakin, C. Mark, El Kharrim, M., Elkins, James W., Epstein, H. E., Espinoza, Jhan C., Famiglietti, James S., Farmer, J., Farrell, S., Fauchald, P., Fausto, R. S., Feely, Richard A., Feng, Z., Fenimore, Chris, Fettweis, X., Fioletov, Vitali E., Flemming, Johannes, Fogt, Ryan L., Folland, Chris, Forbes, B. C., Foster, Michael J., Francis, S. D., Franz, Bryan A., Frey, Richard A., Frith, Stacey M., Froidevaux, Lucien, Ganter, Catherine, Geiger, Erick F., Gerland, S., Gilson, John, Gobron, Nadine, Goldenberg, Stanley B., Gomez, Andrea M., Goni, Gustavo, Grooß, Jens Uwe, Gruber, Alexander, Guard, Charles P., Gugliemin, Mario, Gupta, S. K., Gutiérrez, Dimitri, Haas, C., Hagos, S., Hahn, Sebastian, Haimberger, Leo, Hall, Brad D., Halpert, Michael S., Hamlington, Benjamin D., Hanna, E., Hansen, K., Hanssen-Bauer, L., Harris, Ian, Hartfield, Gail, Heidinger, Andrew K., Heim, Richard R., Helfrich, S., Hemming, D. L., Hendricks, S., Hernández, Rafael, Hernández, Sosa Marieta, Heron, Scott F., Heuzé, C., Hidalgo, Hugo G., Ho, Shu Peng, Hobbs, William R., Horstkotte, T., Huang, Boyin, Hubert, Daan, Hueuzé, Céline, Hurst, Dale F., Ialongo, Iolanda, Ibrahim, M. M., Ijampy, J. A., Inness, Antje, Isaac, Victor, Isaksen, K., Ishii, Masayoshi, Jacobs, Stephanie J., Jeffries, Martin O., Jevrejeva, Svetlana, Jiménez, C., Jin, Xiangze, John, Viju, Johns, William E., Johnsen, Bjørn, Johnson, Bryan, Johnson, Gregory C., Johnson, Kenneth S., Jones, Philip D., Jumaux, Guillaume, Kabidi, Khadija, Kaiser, J. W., Karaköylü, Erdem M., Kato, Seiji, Kazemi, A., Keller, Linda M., Kennedy, John, Kerr, Kenneth, Khan, M. S., Kholodov, A. L., Khoshkam, Mahbobeh, Killick, Rachel, Kim, Hyungjun, Kim, S. J., Klotzbach, Philip J., Knaff, John A., Kohler, J., Korhonen, Johanna, Korshunova, Natalia N., Kramarova, Natalya, Kratz, D. P., Kruger, Andries, Kruk, Michael C., Krumpen, T., Ladd, C., Lakatos, Mónika, Lakkala, Kaisa, Lander, Mark A., Landschützer, Peter, Landsea, Chris W., Lankhorst, Matthias, Lavado-Casimiro, Waldo, Lazzara, Matthew A., Lee, S. E., Lee, T. C., Leuliette, Eric, L'Heureux, Michelle, Li, Tim, Lieser, Jan L., Lin, I. I., Mears, Carl A., Liu, Gang, Li, Bailing, Liu, Hongxing, Locarnini, Ricardo, Loeb, Norman G., Long, Craig S., López, Luis A., Lorrey, Andrew M., Loyola, Diego, Lumpkin, Rick, Luo, Jing Jia, Luojus, K., Luthcke, S., Macias-Fauria, M., Malkova, G. V., Manney, Gloria L., Marcellin, Vernie, Marchenko, S. S., Marengo, José A., Marín, Dora, Marra, John J., Marszelewski, Wlodzimierz, Martens, B., Martin, A., Martínez, Alejandra G., Martínez-Güingla, Rodney, Martínez-Sánchez, Odalys, Marsh, Benjamin L., Lyman, John M., Massom, Robert A., May, Linda, Mayer, Michael, Mazloff, Matthew, McBride, Charlotte, McCabe, M. F., McCarthy, Mark, Meier, W., Meijers, Andrew J.S., Mekonnen, Ademe, Mengistu Tsidu, G., Menzel, W. Paul, Merchant, Christopher J., Meredith, Michael P., Merrifield, Mark A., Miller, Ben, Miralles, Diego G., Mitchum, Gary T., Mitro, Sukarni, Moat, Ben, Mochizuki, Y., Monselesan, Didier, Montzka, Stephen A., Mora, Natalie, Morice, Colin, Mosquera-Vásquez, Kobi, Mostafa, Awatif E., Mote, T., Mudryk, L., Mühle, Jens, Mullan, A. Brett, Müller, Rolf, Myneni, R., Nash, Eric R., Nerem, R. Steven, Newman, L., Newman, Paul A., Nielsen-Gammon, John W., Nieto, Juan José, Noetzli, Jeannette, Noll, Ben E., O'Neel, S., Osborn, Tim J., Osborne, Emily, Overland, J., Oyunjargal, Lamjav, Park, T., Pasch, Richard J., Pascual-Ramírez, Reynaldo, Pastor Saavedra, Maria Asuncion, Paterson, Andrew M., Paulik, Christoph, Pearce, Petra R., Peltier, Alexandre, Pelto, Mauri S., Peng, Liang, Perkins-Kirkpatrick, Sarah E., Perovich, Don, Petropavlovskikh, Irina, Pezza, Alexandre B., Phillips, C., Phillips, David, Phoenix, G., Pinty, Bernard, Pinzon, J., Po-Chedley, S., Polashenski, C., Purkey, Sarah G., Quispe, Nelson, Rajeevan, Madhavan, Rakotoarimalala, C., Rayner, Darren, Raynolds, M. K., Reagan, James, Reid, Phillip, Reimer, Christoph, Rémy, Samuel, Revadekar, Jayashree V., Richardson, A. D., Richter-Menge, Jacqueline, Ricker, R., Rimmer, Alon, Robinson, David A., Rodell, Matthew, Rodriguez Camino, Ernesto, Romanovsky, Vladimir E., Ronchail, Josyane, Rosenlof, Karen H., Rösner, Benjamin, Roth, Chris, Roth, David Mark, Rusak, James A., Rutishäuser, T., Sallée, Jean Bapiste, Sánchez-Lugo, Ahira, Santee, Michelle L., Sasgen, L., Sawaengphokhai, P., Sayad, T. A., Sayouri, Amal, Scambos, Ted A., Scanlon, T., Schenzinger, Verena, Schladow, S. Geoffrey, Schmid, Claudia, Schmid, Martin, Schreck, Carl J., Selkirk, H. B., Send, Uwe, Sensoy, Serhat, Sharp, M., Shi, Lei, Shiklomanov, Nikolai I., Shimaraeva, Svetlana V., Siegel, David A., Silow, Eugene, Sima, Fatou, Simmons, Adrian J., Skirving, William J., Smeed, David A., Smeets, C. J.P.P., Smith, Adam, Smith, Sharon L., Soden, B., Sofieva, Viktoria, Sparks, T. H., Spence, Jacqueline M., Spillane, Sandra, Srivastava, A. K., Stackhouse, Paul W., Stammerjohn, Sharon, Stanitski, Diane M., Steinbrecht, Wolfgang, Stella, José L., Stengel, M., Stephenson, Kimberly, Stephenson, Tannecia S., Strahan, Susan, Streletskiy, Dimitri A., Strong, Alan E., Sun-Mack, Sunny, Sutton, Adrienne J., Swart, Sebastiaan, Sweet, William, Takahashi, Kenneth S., Tamar, Gerard, Taylor, Michael A., Tedesco, M., Thackeray, S. J., Thoman, R. L., Thompson, Philip, Thomson, L., Thorsteinsson, T., Timbal, Bertrand, Timmermans, M. L., TImofeyev, Maxim A., Tirak, Kyle V., Tobin, Skie, Togawa, H., Tømmervik, H., Tourpali, Kleareti, Trachte, Katja, Trewin, Blair C., Triñanes, Joaquin A., Trotman, Adrian R., Tschudi, M., Tucker, C. J., Tye, Mari R., Van As, D., Van De Wal, R. S.W., Van Der Ronald, J. A., Van Der Schalie, Robin, Van Der Schrier, Gerard, Van Der Werf, Guido R., Van Meerbeeck, Cedric J., Velden, Christopher S., Velicogna, I., Verburg, Piet, Vickers, H., Vincent, Lucie A., Vömel, Holger, Vose, Russell S., Wagner, Wolfgang, Walker, D. A., Walsh, J., Wang, Bin, Wang, Junhong, Wang, Lei, Wang, M., Wang, Ray, Wang, Sheng Hung, Wanninkhof, Rik, Watanabe, Shohei, Weber, Mark, Webster, M., Weller, Robert A., Westberry, Toby K., Weyhenmeyer, Gesa A., Whitewood, Robert, Widlansky, Matthew J., Wiese, David N., Wijffels, Susan E., Wilber, Anne C., Wild, Jeanette D., Willett, Kate M., Willis, Josh K., Wolken, G., Wong, Takmeng, Wood, E. F., Wood, K., Woolway, R. Iestyn, Wouters, B., Xue, Yan, Yin, Xungang, Yoon, Huang, York, A., Yu, Lisan, Zambrano, Eduardo, Zhang, Huai Min, Zhang, Peiqun, Zhao, Guanguo, Zhao, Lin, Zhu, Zhiwei, Ziel, R., Ziemke, Jerry R., Ziese, Markus G., Griffin, Jessicca, Hammer, Gregory, Love-Brotak, S. Elizabeth, Misch, Deborah J., Riddle, Deborah B., Slagle, Mary, Sprain, Mara, Veasey, Sara W., McVicar, Tim R., Sub Dynamics Meteorology, Sub Soft Condensed Matter, LS Religiewetenschap, Sub Atmospheric physics and chemistry, Zonder bezoldiging NED, LS Taalverwerving, Leerstoel Tubergen, Afd Chemical Biology and Drug Discovery, Hafd Faculteitsbureau GW, Afd Pharmacology, Dep IRAS, Marine and Atmospheric Research, and OFR - Religious Studies

Subjects
Atmospheric Science
Abstract

In 2017, the dominant greenhouse gases released into Earth's atmosphere-carbon dioxide, methane, and nitrous oxide-reached new record highs. The annual global average carbon dioxide concentration at Earth's surface for 2017 was 405.0 ± 0.1 ppm, 2.2 ppm greater than for 2016 and the highest in the modern atmospheric measurement record and in ice core records dating back as far as 800 000 years. The global growth rate of CO2 has nearly quadrupled since the early 1960s. With ENSO-neutral conditions present in the central and eastern equatorial Pacific Ocean during most of the year and weak La Niña conditions notable at the start and end, the global temperature across land and ocean surfaces ranked as the second or third highest, depending on the dataset, since records began in the mid-to-late 1800s. Notably, it was the warmest non-El Niño year in the instrumental record. Above Earth's surface, the annual lower tropospheric temperature was also either second or third highest according to all datasets analyzed. The lower stratospheric temperature was about 0.2°C higher than the record cold temperature of 2016 according to most of the in situ and satellite datasets. Several countries, including Argentina, Uruguay, Spain, and Bulgaria, reported record high annual temperatures. Mexico broke its annual record for the fourth consecutive year. On 27 January, the temperature reached 43.4°C at Puerto Madryn, Argentina-the highest temperature recorded so far south (43°S) anywhere in the world. On 28 May in Turbat, western Pakistan, the high of 53.5°C tied Pakistan's all-time highest temperature and became the world-record highest temperature for May. In the Arctic, the 2017 land surface temperature was 1.6°C above the 1981-2010 average, the second highest since the record began in 1900, behind only 2016. The five highest annual Arctic temperatures have all occurred since 2007. Exceptionally high temperatures were observed in the permafrost across the Arctic, with record values reported in much of Alaska and northwestern Canada. In August, high sea surface temperature (SST) records were broken for the Chukchi Sea, with some regions as warm as +11°C, or 3° to 4°C warmer than the longterm mean (1982-present). According to paleoclimate studies, today's abnormally warm Arctic air and SSTs have not been observed in the last 2000 years. The increasing temperatures have led to decreasing Arctic sea ice extent and thickness. On 7 March, sea ice extent at the end of the growth season saw its lowest maximum in the 37-year satellite record, covering 8% less area than the 1981-2010 average. The Arctic sea ice minimum on 13 September was the eighth lowest on record and covered 25% less area than the long-term mean. Preliminary data indicate that glaciers across the world lost mass for the 38th consecutive year on record; the declines are remarkably consistent from region to region. Cumulatively since 1980, this loss is equivalent to slicing 22 meters off the top of the average glacier. Antarctic sea ice extent remained below average for all of 2017, with record lows during the first four months. Over the continent, the austral summer seasonal melt extent and melt index were the second highest since 2005, mostly due to strong positive anomalies of air temperature over most of the West Antarctic coast. In contrast, the East Antarctic Plateau saw record low mean temperatures in March. The year was also distinguished by the second smallest Antarctic ozone hole observed since 1988. Across the global oceans, the overall long-term SST warming trend remained strong. Although SST cooled slightly from 2016 to 2017, the last three years produced the three highest annual values observed; these high anomalies have been associated with widespread coral bleaching. The most recent global coral bleaching lasted three full years, June 2014 to May 2017, and was the longest, most widespread, and almost certainly most destructive such event on record. Global integrals of 0-700-m and 0-2000-m ocean heat content reached record highs in 2017, and global mean sea level during the year became the highest annual average in the 25-year satellite altimetry record, rising to 77 mm above the 1993 average. In the tropics, 2017 saw 85 named tropical storms, slightly above the 1981-2010 average of 82. The North Atlantic basin was the only basin that featured an above-normal season, its seventh most active in the 164-year record. Three hurricanes in the basin were especially notable. Harvey produced record rainfall totals in areas of Texas and Louisiana, including a storm total of 1538.7 mm near Beaumont, Texas, which far exceeds the previous known U.S. tropical cyclone record of 1320.8 mm. Irma was the strongest tropical cyclone globally in 2017 and the strongest Atlantic hurricane outside of the Gulf of Mexico and Caribbean on record with maximum winds of 295 km h-1. Maria caused catastrophic destruction across the Caribbean Islands, including devastating wind damage and flooding across Puerto Rico. Elsewhere, the western North Pacific, South Indian, and Australian basins were all particularly quiet. Precipitation over global land areas in 2017 was clearly above the long-term average. Among noteworthy regional precipitation records in 2017, Russia reported its second wettest year on record (after 2013) and Norway experienced its sixth wettest year since records began in 1900. Across India, heavy rain and flood-related incidents during the monsoon season claimed around 800 lives. In August and September, above-normal precipitation triggered the most devastating floods in more than a decade in the Venezuelan states of Bolívar and Delta Amacuro. In Nigeria, heavy rain during August and September caused the Niger and Benue Rivers to overflow, bringing floods that displaced more than 100 000 people. Global fire activity was the lowest since at least 2003; however, high activity occurred in parts of North America, South America, and Europe, with an unusually long season in Spain and Portugal, which had their second and third driest years on record, respectively. Devastating fires impacted British Columbia, destroying 1.2 million hectares of timber, bush, and grassland, due in part to the region's driest summer on record. In the United States, an extreme western wildfire season burned over 4 million hectares; the total costs of $18 billion tripled the previous U.S. annual wildfire cost record set in 1991.

Published
2018

20. Snow on Arctic sea ice: model representation and last decade changes

Author

Castro-Morales, K., Ricker, R., and Gerdes, R.

Subjects
geography, geography.geographical_feature_category, Firn, Snow field, Snow, Atmospheric sciences, Snow hydrology, Arctic ice pack, 13. Climate action, Climatology, Snow line, Sea ice, Cryosphere, Environmental science
Abstract

Together with sea ice, Arctic snow has experienced vast changes during the last decade due to a warming climate. Thus, it is relevant to study the past and present changes of Arctic snow to understand the implications to the sea ice component, precipitation, heat and radiation budgets. In this study, we analyze the changes of snow depth between 2000 and 2013 at regional scale represented in an Arctic coupled sea ice-general circulation model. We evaluate the model performance by direct comparison of the modeled snow depths (hs_mod) to snow depths from radar measurements from the NASA Operation IceBridge (hs_OIB) during the flight campaigns completed from 2009 to 2013. Despite the description of the snow in our model is simple (i.e. single layer without explicit snow redistribution processes) as in many current sea-ice models; the latitudinal distribution of hs_mod in the western Arctic is in good agreement to observations. The hs_mod is on average 3 cm thicker than hs_OIB in latitudes > 76° N. According to the model results, the hs in 2013 decreased 21 % with respect to the multi-year mean between 2000 and 2013. This snow reduction occurred mainly in FYI dominated areas, and is in good agreement to the year-to-year loss of sea ice, also well reproduced by the model. In a simple snow mass budget, our results show that 65 % of the yearly accumulated snow is lost by sublimation and snowmelt due to the heat transfer between the snow/ice interface and the atmosphere. Although the snow layer accumulates again every year, the long-term reduction in the summer sea-ice extent ultimately affects the maximum spring accumulation of snow. The model results exhibit a last decade thinning of the snowpack that is however one order of magnitude lower than previous estimates based on radar measurements. We suggest that the later is partially due to the lack of explicit snow redistribution processes in the model, emphasizing the need to include these in current sea-ice models to improve the snow representations.

Published
2015
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21. Seasonal sea ice predictions for the Arctic based on assimilation of remotely sensed observations

Author

Kauker, F., Kaminski, T., Ricker, R., Toudal-Pedersen, L., Dybkjaer, G., Melsheimer, C., Eastwood, S., Sumata, H., Karcher, M., and Gerdes, R.

Subjects
Drift ice, Arctic sea ice decline, geography, geography.geographical_feature_category, Climatology, Sea ice thickness, Sea ice, Environmental science, Cryosphere, Sea ice concentration, Arctic ice pack, Arctic geoengineering
Abstract

The recent thinning and shrinking of the Arctic sea ice cover has increased the interest in seasonal sea ice forecasts. Typical tools for such forecasts are numerical models of the coupled ocean sea ice system such as the North Atlantic/Arctic Ocean Sea Ice Model (NAOSIM). The model uses as input the initial state of the system and the atmospheric boundary condition over the forecasting period. This study investigates the potential of remotely sensed ice thickness observations in constraining the initial model state. For this purpose it employs a variational assimilation system around NAOSIM and the Alfred Wegener Institute's CryoSat-2 ice thickness product in conjunction with the University of Bremen's snow depth product and the OSI SAF ice concentration and sea surface temperature products. We investigate the skill of predictions of the summer ice conditions starting in March for three different years. Straightforward assimilation of the above combination of data streams results in slight improvements over some regions (especially in the Beaufort Sea) but degrades the over-all fit to independent observations. A considerable enhancement of forecast skill is demonstrated for a bias correction scheme for the CryoSat-2 ice thickness product that uses a spatially varying scaling factor.

Published
2015
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22. State of the Climate in 2017

Author

Arndt, D. S., Blunden, J., Hartfield, G., Ackerman, Steven A., Adler, Robert, Alfaro, Eric J., Allan, Richard P., Allan, Rob, Alves, Lincoln M., Amador, Jorge A., Andreassen, L. M., Argueez, Anthony, Arndt, Derek S., Azorin-molina, Cesar, Baez, Julian, Bardin, M. U., Barichivich, Jonathan, Baringer, Molly O., Barreira, Sandra, Baxter, Stephen, Beck, H. E., Becker, Andreas, Bedka, Kristopher M., Bell, Gerald D., Belmont, M., Benedetti, Angela, Berrisford, Paul, Berry, David I., Bhatt, U. S., Bissolli, Peter, Bjerke, J., Blake, Eric S., Bosilovich, Michael G., Boucher, Olivier, Box, J. E., Boyer, Tim, Braathen, Geir O., Bromwich, David H., Brown, R., Buehler, S., Bulygina, Olga N., Burgess, D., Calderon, Blanca, Camargo, Suzana J., Campbell, Jayaka D., Cappelen, J., Carrea, Laura, Carter, Brendan R., Chambers, Don P., Cheng, Ming-dean, Christiansen, Hanne H., Christy, John R., Chung, E. -s., Clem, Kyle R., Coelho, Caio A. S., Coldewey-egbers, Melanie, Colwell, Steve, Cooper, Owen R., Copland, L., Crouch, Jake, Davis, Sean M., De Eyto, Elvira, De Jeu, Richard A. M., De Laat, Jos, Degasperi, Curtis L., Degenstein, Doug, Demircan, M., Derksen, C., Di Girolamo, Larry, Diamond, Howard J., Dlugokencky, Ed J., Dohan, Kathleen, Dokulil, Martin T., Dolman, A. Johannes, Domingues, Catia M., Donat, Markus G., Dong, Shenfu, Dorigo, Wouter A., Drozdov, D. S., Dunn, Robert J. H., Dutton, Geoff S., Elkharrim, M., Elkins, James W., Epstein, H. E., Espinoza, Jhan C., Famiglietti, James S., Farrell, S., Fausto, R. S., Feely, Richard A., Feng, Z., Fenimore, Chris, Fettweis, X., Fioletov, Vitali E., Flemming, Johannes, Fogt, Ryan L., Folland, Chris, Forbes, B. C., Foster, Michael J., Francis, S. D., Franz, Bryan A., Frey, Richard A., Frith, Stacey M., Froidevaux, Lucien, Ganter, Catherine, Gerland, S., Gilson, John, Gobron, Nadine, Goldenberg, Stanley B., Goni, Gustavo, Grooss, J. -u., Gruber, Alexander, Guard, Charles, Gupta, S. K., Gutierrez, J. M., Haas, C., Hagos, S., Hahn, Sebastian, Haimberger, Leo, Hall, Brad D., Halpert, Michael S., Hamlington, Benjamin D., Hanna, E., Hanssen-bauer, I, Harris, Ian, Heidinger, Andrew K., Heim, Richard R., Jr., Hendricks, S., Hernandez, Marieta, Hernandez, Rafael, Hidalgo, Hugo G., Ho, Shu-peng, Hobbs, William R., Huang, Boyin, Hurst, Dale F., Ialongo, I., Ijampy, J. A., Inness, Antje, Isaksen, K., Ishii, Masayoshi, Jevrejeva, Svetlana, Jimenez, C., Jin Xiangze, John, Viju, Johns, William E., Johnsen, B., Johnson, Bryan, Johnson, Gregory C., Johnson, Kenneth S., Jones, Philip D., Jumaux, Guillaume, Kabidi, Khadija, Kaiser, J. W., Kato, Seiji, Kazemi, A., Keller, Linda M., Kennedy, John, Kerr, Kenneth, Kholodov, A. L., Khoshkam, Mahbobeh, Killick, Rachel, Kim, Hyungjun, Kim, S. -j., Klotzbach, Philip J., Knaff, John A., Kohler, J., Korhonen, Johanna, Korshunova, Natalia N., Kramarova, Natalya, Kratz, D. P., Kruger, Andries, Kruk, Michael C., Krumpen, T., Lakatos, M., Lakkala, K., Lander, Mark A., Landschuetzer, Peter, Landsea, Chris W., Lankhorst, Matthias, Lazzara, Matthew A., Leuliette, Eric, L'Heureux, Michelle, Lieser, Jan L., Lin, I-i, Liu, Hongxing, Liu, Yinghui, Locarnini, Ricardo, Loeb, Norman G., Long, Craig S., Lorrey, Andrew M., Loyola, Diego, Lumpkin, Rick, Luo, Jing-jia, Luojus, K., Lyman, John M., Macias-fauria, M., Malkova, G. V., Manney, G., Marchenko, S. S., Marengo, Jose A., Marra, John J., Marszelewski, Wlodzimierz, Martens, B., Martinez-gueingla, Rodney, Massom, Robert A., May, Linda, Mayer, Michael, Mazloff, Matthew, Mcbride, Charlotte, Mccabe, M. F., Mccarthy, M., Mcvicar, Tim R., Mears, Carl A., Meier, W., Mekonnen, A., Mengistu Tsidu, G., Menzel, W. Paul, Merchant, Christopher J., Meredith, Michael P., Merrifield, Mark A., Miralles, Diego G., Mitchum, Gary T., Mitro, Srkani, Monselesan, Didier, Montzka, Stephen A., Mora, Natalie, Morice, Colin, Mote, T., Mudryk, L., Muehle, Jens, Mullan, A. Brett, Mueller, R., Nash, Eric R., Nerem, R. Steven, Newman, Louise, Newman, Paul A., Nieto, Juan Jose, Noetzli, Jeannette, O'Neel, S., Osborn, Tim J., Overland, J., Oyunjargal, Lamjav, Park, E-hyung, Pasch, Richard J., Pascual-ramirez, Reynaldo, Paterson, Andrew M., Pearce, Petra R., Pelto, Mauri S., Perkins-kirkpatrick, Sarah E., Perovich, D., Petropavlovskikh, Irina, Pezza, Alexandre B., Phillips, C., Phillips, David, Phoenix, G., Pinty, Bernard, Rajeevan, Madhavan, Rayner, Darren, Raynolds, M. K., Reagan, James, Reid, Phillip, Reimer, Christoph, Remy, Samuel, Revadekar, Jayashree V., Richter-menge, J., Rimmer, Alon, Robinson, David A., Rodell, Matthew, Romanovsky, Vladimir E., Ronchail, Josyane, Rosenlof, Karen H., Roth, Chris, Rusak, James A., Sallee, Jean-bapiste, Sanchez-lugo, Ahira, Santee, Michelle L., Sawaengphokhai, P., Sayouri, Amal, Scambos, Ted A., Schladow, S. Geoffrey, Schmid, Claudia, Schmid, Martin, Schreck, Carl J., Iii, Schuur, Ted, Selkirk, H. B., Send, Uwe, Sensoy, Serhat, Sharp, M., Shi, Lei, Shiklomanov, Nikolai I., Shimaraeva, Svetlana V., Siegel, David A., Signorini, Sergio R., Sima, Fatou, Simmons, Adrian J., Smeed, David A., Smeets, C. J. P. P., Smith, Adam, Smith, Sharon L., Soden, B., Spence, Jaqueline M., Srivastava, A. K., Stackhouse, Paul W., Jr., Stammerjohn, Sharon, Steinbrecht, Wolfgang, Stella, Jose L., Stephenson, Tannecia S., Strahan, Susan, Streletskiy, Dimitri A., Sun-mack, Sunny, Swart, Sebastiaan, Sweet, William, Tamar, Gerard, Taylor, Michael A., Tedesco, M., Thoman, R. L., Thompson, L., Thompson, Philip R., Timmermans, M. -l., Tobin, Skie, Trachte, Katja, Trewin, Blair C., Trotman, Adrian R., Tschudi, M., Van As, D., Van De Wal, R. S. W., Van Der Schalie, Robin, Van Der Schrier, Gerard, Van Der Werf, Guido R., Van Meerbeeck, Cedric J., Velicogna, I., Verburg, Piet, Vincent, Lucie A., Voemel, Holger, Vose, Russell S., Wagner, Wolfgang, Walker, D. A., Walsh, J., Wang, Bin, Wang, Chunzai, Wang, Junhong, Wang, Lei, Wang, M., Wang, Sheng-hung, Wanninkhof, Rik, Watanabe, Shohei, Weber, Mark, Weller, Robert A., Weyhenmeyer, Gesa A., Whitewood, Robert, Wiese, David N., Wijffels, Susan E., Wilber, Anne C., Wild, Jeanette D., Willett, Kate M., Willis, Josh K., Wolken, G., Wong, Takmeng, Wood, E. F., Woolway, R. Iestyn, Wouters, B., Xue, Yan, Yin, Xungang, Yu, Lisan, Zambrano, Eduardo, Zhang, Huai-min, Zhang, Peiqun, Zhao, Guanguo, Zhao, Lin, Ziemke, Jerry R., Abernethy, R., Albanil, Encarnacion Adelina, Aldeco, Laura S., Aliaga-nestares, Vannia, Anderson, John, Armitage, C., Avalos, Grinia, Behe, Carolina, Bellouin, Nicolas, Bernhard, G. H., Blenkinsop, Stephen, Bolmgren, K., Bouchon, Marilu, Campbell, Ethan C., Castro, Anabel, Costanza, Carol, Covey, Curt, Coy, Lawrence, Cronin, T., Cruzado, Luis, Daniel, Raychelle, Davletshin, S. G., De La Cour, Jacqueline L., Deline, P., Dewitte, Boris, Dhurmea, R., Dickerson, C., Domingues, Ricardo, Durre, Imke, Eakin, C. Mark, Farmer, J., Fauchald, P., Geiger, Erick F., Gomez, Andrea M., Gugliemin, Mario, Hansen, K., Helfrich, S., Hemming, D. L., Heron, Scott F., Heuze, C., Horstkotte, T., Hubert, Daan, Hueuze, Celine, Ibrahim, M. M., Isaac, Victor, Jacobs, Stephanie J., Jeffries, Martin O., Karakoylu, Erdem M., Khan, M. S., Ladd, C., Lavado-casimiro, Waldo, Lee, S. -e, Lee, T. C., Li, Bailing, Li, Tim, Lopez, Luis A., Luthcke, S., Marcellin, Vernie, Marin, Dora, Marsh, Benjamin L., Martin, A, Martinez, Alejandra G., Martinez-sanchez, Odalys, Meijers, Andrew J. S., Miller, Ben, Moat, Ben, Mochizuki, Y., Mosquera-vasquez, Kobi, Mostafa, Awatif E., Nielsen-gammon, John W., Noll, Ben E., Osborne, Emily, Pastor, Saavedra Maria Asuncion, Paulik, Christoph, Peltier, Alexandre, Pinzon, J., Po-chedley, S., Polashenski, C., Purkey, Sarah G., Quispe, Nelson, Rakotoarimalala, C., Richardson, A. D., Ricker, R, Rodriguez, Camino Ernesto, Rosner, Benjamin, Roth, David Mark, Rutishauser, T., Sasgen, L., Sayad, T. A., Scanlon, T., Schenzinger, Verena, Silow, Eugene, Skirving, William J., Sofieva, Viktoria, Sparks, T. H., Spillane, Sandra, Stanitski, Diane M., Stengel, M., Stephenson, Kimberly, Strong, Alan E., Sutton, Adrienne J., Takahashi, Kenneth S., Thackeray, S. J., Thomson, Lthorsteinsson T., Timbal, Bertrand, Timofeyev, Maxim A., Tirak, Kyle, V, Togawa, H., Tommervik, H., Tourpali, Kleareti, Trinanes, Joaquin A., Tucker, C. J., Tye, Mari R., Van Der A, Ronald J., Velden, Christopher S., Vickers, H., Webster, M., Westberry, Toby K., Widlansky, Matthew J., Wood, K., Yoon, Huang, York, A., Zhu, Zhiwei, Ziel, R., Ziese, Markus G., Arndt, D. S., Blunden, J., Hartfield, G., Ackerman, Steven A., Adler, Robert, Alfaro, Eric J., Allan, Richard P., Allan, Rob, Alves, Lincoln M., Amador, Jorge A., Andreassen, L. M., Argueez, Anthony, Arndt, Derek S., Azorin-molina, Cesar, Baez, Julian, Bardin, M. U., Barichivich, Jonathan, Baringer, Molly O., Barreira, Sandra, Baxter, Stephen, Beck, H. E., Becker, Andreas, Bedka, Kristopher M., Bell, Gerald D., Belmont, M., Benedetti, Angela, Berrisford, Paul, Berry, David I., Bhatt, U. S., Bissolli, Peter, Bjerke, J., Blake, Eric S., Bosilovich, Michael G., Boucher, Olivier, Box, J. E., Boyer, Tim, Braathen, Geir O., Bromwich, David H., Brown, R., Buehler, S., Bulygina, Olga N., Burgess, D., Calderon, Blanca, Camargo, Suzana J., Campbell, Jayaka D., Cappelen, J., Carrea, Laura, Carter, Brendan R., Chambers, Don P., Cheng, Ming-dean, Christiansen, Hanne H., Christy, John R., Chung, E. -s., Clem, Kyle R., Coelho, Caio A. S., Coldewey-egbers, Melanie, Colwell, Steve, Cooper, Owen R., Copland, L., Crouch, Jake, Davis, Sean M., De Eyto, Elvira, De Jeu, Richard A. M., De Laat, Jos, Degasperi, Curtis L., Degenstein, Doug, Demircan, M., Derksen, C., Di Girolamo, Larry, Diamond, Howard J., Dlugokencky, Ed J., Dohan, Kathleen, Dokulil, Martin T., Dolman, A. Johannes, Domingues, Catia M., Donat, Markus G., Dong, Shenfu, Dorigo, Wouter A., Drozdov, D. S., Dunn, Robert J. H., Dutton, Geoff S., Elkharrim, M., Elkins, James W., Epstein, H. E., Espinoza, Jhan C., Famiglietti, James S., Farrell, S., Fausto, R. S., Feely, Richard A., Feng, Z., Fenimore, Chris, Fettweis, X., Fioletov, Vitali E., Flemming, Johannes, Fogt, Ryan L., Folland, Chris, Forbes, B. C., Foster, Michael J., Francis, S. D., Franz, Bryan A., Frey, Richard A., Frith, Stacey M., Froidevaux, Lucien, Ganter, Catherine, Gerland, S., Gilson, John, Gobron, Nadine, Goldenberg, Stanley B., Goni, Gustavo, Grooss, J. -u., Gruber, Alexander, Guard, Charles, Gupta, S. K., Gutierrez, J. M., Haas, C., Hagos, S., Hahn, Sebastian, Haimberger, Leo, Hall, Brad D., Halpert, Michael S., Hamlington, Benjamin D., Hanna, E., Hanssen-bauer, I, Harris, Ian, Heidinger, Andrew K., Heim, Richard R., Jr., Hendricks, S., Hernandez, Marieta, Hernandez, Rafael, Hidalgo, Hugo G., Ho, Shu-peng, Hobbs, William R., Huang, Boyin, Hurst, Dale F., Ialongo, I., Ijampy, J. A., Inness, Antje, Isaksen, K., Ishii, Masayoshi, Jevrejeva, Svetlana, Jimenez, C., Jin Xiangze, John, Viju, Johns, William E., Johnsen, B., Johnson, Bryan, Johnson, Gregory C., Johnson, Kenneth S., Jones, Philip D., Jumaux, Guillaume, Kabidi, Khadija, Kaiser, J. W., Kato, Seiji, Kazemi, A., Keller, Linda M., Kennedy, John, Kerr, Kenneth, Kholodov, A. L., Khoshkam, Mahbobeh, Killick, Rachel, Kim, Hyungjun, Kim, S. -j., Klotzbach, Philip J., Knaff, John A., Kohler, J., Korhonen, Johanna, Korshunova, Natalia N., Kramarova, Natalya, Kratz, D. P., Kruger, Andries, Kruk, Michael C., Krumpen, T., Lakatos, M., Lakkala, K., Lander, Mark A., Landschuetzer, Peter, Landsea, Chris W., Lankhorst, Matthias, Lazzara, Matthew A., Leuliette, Eric, L'Heureux, Michelle, Lieser, Jan L., Lin, I-i, Liu, Hongxing, Liu, Yinghui, Locarnini, Ricardo, Loeb, Norman G., Long, Craig S., Lorrey, Andrew M., Loyola, Diego, Lumpkin, Rick, Luo, Jing-jia, Luojus, K., Lyman, John M., Macias-fauria, M., Malkova, G. V., Manney, G., Marchenko, S. S., Marengo, Jose A., Marra, John J., Marszelewski, Wlodzimierz, Martens, B., Martinez-gueingla, Rodney, Massom, Robert A., May, Linda, Mayer, Michael, Mazloff, Matthew, Mcbride, Charlotte, Mccabe, M. F., Mccarthy, M., Mcvicar, Tim R., Mears, Carl A., Meier, W., Mekonnen, A., Mengistu Tsidu, G., Menzel, W. Paul, Merchant, Christopher J., Meredith, Michael P., Merrifield, Mark A., Miralles, Diego G., Mitchum, Gary T., Mitro, Srkani, Monselesan, Didier, Montzka, Stephen A., Mora, Natalie, Morice, Colin, Mote, T., Mudryk, L., Muehle, Jens, Mullan, A. Brett, Mueller, R., Nash, Eric R., Nerem, R. Steven, Newman, Louise, Newman, Paul A., Nieto, Juan Jose, Noetzli, Jeannette, O'Neel, S., Osborn, Tim J., Overland, J., Oyunjargal, Lamjav, Park, E-hyung, Pasch, Richard J., Pascual-ramirez, Reynaldo, Paterson, Andrew M., Pearce, Petra R., Pelto, Mauri S., Perkins-kirkpatrick, Sarah E., Perovich, D., Petropavlovskikh, Irina, Pezza, Alexandre B., Phillips, C., Phillips, David, Phoenix, G., Pinty, Bernard, Rajeevan, Madhavan, Rayner, Darren, Raynolds, M. K., Reagan, James, Reid, Phillip, Reimer, Christoph, Remy, Samuel, Revadekar, Jayashree V., Richter-menge, J., Rimmer, Alon, Robinson, David A., Rodell, Matthew, Romanovsky, Vladimir E., Ronchail, Josyane, Rosenlof, Karen H., Roth, Chris, Rusak, James A., Sallee, Jean-bapiste, Sanchez-lugo, Ahira, Santee, Michelle L., Sawaengphokhai, P., Sayouri, Amal, Scambos, Ted A., Schladow, S. Geoffrey, Schmid, Claudia, Schmid, Martin, Schreck, Carl J., Iii, Schuur, Ted, Selkirk, H. B., Send, Uwe, Sensoy, Serhat, Sharp, M., Shi, Lei, Shiklomanov, Nikolai I., Shimaraeva, Svetlana V., Siegel, David A., Signorini, Sergio R., Sima, Fatou, Simmons, Adrian J., Smeed, David A., Smeets, C. J. P. P., Smith, Adam, Smith, Sharon L., Soden, B., Spence, Jaqueline M., Srivastava, A. K., Stackhouse, Paul W., Jr., Stammerjohn, Sharon, Steinbrecht, Wolfgang, Stella, Jose L., Stephenson, Tannecia S., Strahan, Susan, Streletskiy, Dimitri A., Sun-mack, Sunny, Swart, Sebastiaan, Sweet, William, Tamar, Gerard, Taylor, Michael A., Tedesco, M., Thoman, R. L., Thompson, L., Thompson, Philip R., Timmermans, M. -l., Tobin, Skie, Trachte, Katja, Trewin, Blair C., Trotman, Adrian R., Tschudi, M., Van As, D., Van De Wal, R. S. W., Van Der Schalie, Robin, Van Der Schrier, Gerard, Van Der Werf, Guido R., Van Meerbeeck, Cedric J., Velicogna, I., Verburg, Piet, Vincent, Lucie A., Voemel, Holger, Vose, Russell S., Wagner, Wolfgang, Walker, D. A., Walsh, J., Wang, Bin, Wang, Chunzai, Wang, Junhong, Wang, Lei, Wang, M., Wang, Sheng-hung, Wanninkhof, Rik, Watanabe, Shohei, Weber, Mark, Weller, Robert A., Weyhenmeyer, Gesa A., Whitewood, Robert, Wiese, David N., Wijffels, Susan E., Wilber, Anne C., Wild, Jeanette D., Willett, Kate M., Willis, Josh K., Wolken, G., Wong, Takmeng, Wood, E. F., Woolway, R. Iestyn, Wouters, B., Xue, Yan, Yin, Xungang, Yu, Lisan, Zambrano, Eduardo, Zhang, Huai-min, Zhang, Peiqun, Zhao, Guanguo, Zhao, Lin, Ziemke, Jerry R., Abernethy, R., Albanil, Encarnacion Adelina, Aldeco, Laura S., Aliaga-nestares, Vannia, Anderson, John, Armitage, C., Avalos, Grinia, Behe, Carolina, Bellouin, Nicolas, Bernhard, G. H., Blenkinsop, Stephen, Bolmgren, K., Bouchon, Marilu, Campbell, Ethan C., Castro, Anabel, Costanza, Carol, Covey, Curt, Coy, Lawrence, Cronin, T., Cruzado, Luis, Daniel, Raychelle, Davletshin, S. G., De La Cour, Jacqueline L., Deline, P., Dewitte, Boris, Dhurmea, R., Dickerson, C., Domingues, Ricardo, Durre, Imke, Eakin, C. Mark, Farmer, J., Fauchald, P., Geiger, Erick F., Gomez, Andrea M., Gugliemin, Mario, Hansen, K., Helfrich, S., Hemming, D. L., Heron, Scott F., Heuze, C., Horstkotte, T., Hubert, Daan, Hueuze, Celine, Ibrahim, M. M., Isaac, Victor, Jacobs, Stephanie J., Jeffries, Martin O., Karakoylu, Erdem M., Khan, M. S., Ladd, C., Lavado-casimiro, Waldo, Lee, S. -e, Lee, T. C., Li, Bailing, Li, Tim, Lopez, Luis A., Luthcke, S., Marcellin, Vernie, Marin, Dora, Marsh, Benjamin L., Martin, A, Martinez, Alejandra G., Martinez-sanchez, Odalys, Meijers, Andrew J. S., Miller, Ben, Moat, Ben, Mochizuki, Y., Mosquera-vasquez, Kobi, Mostafa, Awatif E., Nielsen-gammon, John W., Noll, Ben E., Osborne, Emily, Pastor, Saavedra Maria Asuncion, Paulik, Christoph, Peltier, Alexandre, Pinzon, J., Po-chedley, S., Polashenski, C., Purkey, Sarah G., Quispe, Nelson, Rakotoarimalala, C., Richardson, A. D., Ricker, R, Rodriguez, Camino Ernesto, Rosner, Benjamin, Roth, David Mark, Rutishauser, T., Sasgen, L., Sayad, T. A., Scanlon, T., Schenzinger, Verena, Silow, Eugene, Skirving, William J., Sofieva, Viktoria, Sparks, T. H., Spillane, Sandra, Stanitski, Diane M., Stengel, M., Stephenson, Kimberly, Strong, Alan E., Sutton, Adrienne J., Takahashi, Kenneth S., Thackeray, S. J., Thomson, Lthorsteinsson T., Timbal, Bertrand, Timofeyev, Maxim A., Tirak, Kyle, V, Togawa, H., Tommervik, H., Tourpali, Kleareti, Trinanes, Joaquin A., Tucker, C. J., Tye, Mari R., Van Der A, Ronald J., Velden, Christopher S., Vickers, H., Webster, M., Westberry, Toby K., Widlansky, Matthew J., Wood, K., Yoon, Huang, York, A., Zhu, Zhiwei, Ziel, R., and Ziese, Markus G.

Abstract

In 2017, the dominant greenhouse gases released into Earth’s atmosphere—carbon dioxide, methane, and nitrous oxide— reached new record highs. The annual global average carbon dioxide concentration at Earth’s surface for 2017 was 405.0 ± 0.1 ppm, 2.2 ppm greater than for 2016 and the highest in the modern atmospheric measurement record and in ice core records dating back as far as 800 000 years. The global growth rate of CO2 has nearly quadrupled since the early 1960s. With ENSO-neutral conditions present in the central and eastern equatorial Pacific Ocean during most of the year and weak La Niña conditions notable at the start and end, the global temperature across land and ocean surfaces ranked as the second or third highest, depending on the dataset, since records began in the mid-to-late 1800s. Notably, it was the warmest non-El Niño year in the instrumental record. Above Earth’s surface, the annual lower tropospheric temperature was also either second or third highest according to all datasets analyzed. The lower stratospheric temperature was about 0.2°C higher than the record cold temperature of 2016 according to most of the in situ and satellite datasets. Several countries, including Argentina, Uruguay, Spain, and Bulgaria, reported record high annual temperatures. Mexico broke its annual record for the fourth consecutive year. On 27 January, the temperature reached 43.4°C at Puerto Madryn, Argentina—the highest temperature recorded so far south (43°S) anywhere in the world. On 28 May in Turbat, western Pakistan, the high of 53.5°C tied Pakistan’s all-time highest temperature and became the world-record highest temperature for May. In the Arctic, the 2017 land surface temperature was 1.6°C above the 1981–2010 average, the second highest since the record began in 1900, behind only 2016. The five highest annual Arctic temperatures have all occurred since 2007. Exceptionally high temperatures were observed in the permafrost across the Arctic, with record values r

Published
2018
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23. State of the climate in 2017

Author

Sub Dynamics Meteorology, Sub Soft Condensed Matter, LS Religiewetenschap, Sub Atmospheric physics and chemistry, Zonder bezoldiging NED, LS Taalverwerving, Leerstoel Tubergen, Afd Chemical Biology and Drug Discovery, Hafd Faculteitsbureau GW, Afd Pharmacology, Dep IRAS, Marine and Atmospheric Research, OFR - Religious Studies, Abernethy, R., Ackerman, Steven A., Adler, R., Albanil Encarnación, Adelina, Aldeco, Laura S., Alfaro, Eric J., Aliaga-Nestares, Vannia, Allan, Richard P., Allan, Rob, Alves, Lincoln M., Amador, Jorge A., Anderson, John, Andreassen, L. M., Argüez, Anthony, Armitage, C., Arndt, Derek S., Avalos, Grinia, Azorin-Molina, César, Báez, Julián, Bardin, M. Yu, Barichivich, Jonathan, Baringer, Molly O., Barreira, Sandra, Baxter, Stephen, Beck, H. E., Becker, Andreas, Bedka, Kristopher M., Behe, Carolina, Bell, Gerald D., Bellouin, Nicolas, Belmont, M., Benedetti, Angela, Bernhard, G. H., Berrisford, Paul, Berry, David I., Bhatt, U. S., Bissolli, Peter, Bjerke, J., Blake, Eric S., Blenkinsop, Stephen, Blunden, Jessica, Bolmgren, K., Bosilovich, Michael G., Boucher, Olivier, Bouchon, Marilú, Box, J. E., Boyer, Tim, Braathen, Geir O., Bromwich, David H., Brown, R., Buehler, S., Bulygina, Olga N., Burgess, D., Calderón, Blanca, Camargo, Suzana J., Campbell, Ethan C., Campbell, Jayaka D., Cappelen, J., Carrea, Laura, Carter, Brendan R., Castro, Anabel, Chambers, Don P., Cheng, Lijing, Christiansen, Hanne H., Christy, John R., Chung, E. S., Clem, Kyle R., Coelho, Caio A.S., Coldewey-Egbers, Melanie, Colwell, Steve, Cooper, Owen R., Copland, L., Costanza, Carol, Covey, Curt, Coy, Lawrence, Cronin, T., Crouch, Jake, Cruzado, Luis, Daniel, Raychelle, Davis, Sean M., Davletshin, S. G., De Eyto, Elvira, De Jeu, Richard A.M., De La Cour, Jacqueline L., De Laat, Jos, De Gasperi, Curtis L., Degenstein, Doug, Deline, P., Demircan, Mesut, Derksen, C., Dewitte, Boris, Dhurmea, R., Di Girolamo, Larry, Diamond, Howard J., Dickerson, C., Dlugokencky, Ed J., Dohan, Kathleen, Dokulil, Martin T., Dolman, A. Johannes, Domingues, Catia M., Domingues, Ricardo, Donat, Markus G., Dong, Shenfu, Dorigo, Wouter A., Drozdov, D. S., Dunn, Robert J.H., Durre, Imke, Dutton, Geoff S., Eakin, C. Mark, El Kharrim, M., Elkins, James W., Epstein, H. E., Espinoza, Jhan C., Famiglietti, James S., Farmer, J., Farrell, S., Fauchald, P., Fausto, R. S., Feely, Richard A., Feng, Z., Fenimore, Chris, Fettweis, X., Fioletov, Vitali E., Flemming, Johannes, Fogt, Ryan L., Folland, Chris, Forbes, B. C., Foster, Michael J., Francis, S. D., Franz, Bryan A., Frey, Richard A., Frith, Stacey M., Froidevaux, Lucien, Ganter, Catherine, Geiger, Erick F., Gerland, S., Gilson, John, Gobron, Nadine, Goldenberg, Stanley B., Gomez, Andrea M., Goni, Gustavo, Grooß, Jens Uwe, Gruber, Alexander, Guard, Charles P., Gugliemin, Mario, Gupta, S. K., Gutiérrez, Dimitri, Haas, C., Hagos, S., Hahn, Sebastian, Haimberger, Leo, Hall, Brad D., Halpert, Michael S., Hamlington, Benjamin D., Hanna, E., Hansen, K., Hanssen-Bauer, L., Harris, Ian, Hartfield, Gail, Heidinger, Andrew K., Heim, Richard R., Helfrich, S., Hemming, D. L., Hendricks, S., Hernández, Rafael, Hernández, Sosa Marieta, Heron, Scott F., Heuzé, C., Hidalgo, Hugo G., Ho, Shu Peng, Hobbs, William R., Horstkotte, T., Huang, Boyin, Hubert, Daan, Hueuzé, Céline, Hurst, Dale F., Ialongo, Iolanda, Ibrahim, M. M., Ijampy, J. A., Inness, Antje, Isaac, Victor, Isaksen, K., Ishii, Masayoshi, Jacobs, Stephanie J., Jeffries, Martin O., Jevrejeva, Svetlana, Jiménez, C., Jin, Xiangze, John, Viju, Johns, William E., Johnsen, Bjørn, Johnson, Bryan, Johnson, Gregory C., Johnson, Kenneth S., Jones, Philip D., Jumaux, Guillaume, Kabidi, Khadija, Kaiser, J. W., Karaköylü, Erdem M., Kato, Seiji, Kazemi, A., Keller, Linda M., Kennedy, John, Kerr, Kenneth, Khan, M. S., Kholodov, A. L., Khoshkam, Mahbobeh, Killick, Rachel, Kim, Hyungjun, Kim, S. J., Klotzbach, Philip J., Knaff, John A., Kohler, J., Korhonen, Johanna, Korshunova, Natalia N., Kramarova, Natalya, Kratz, D. P., Kruger, Andries, Kruk, Michael C., Krumpen, T., Ladd, C., Lakatos, Mónika, Lakkala, Kaisa, Lander, Mark A., Landschützer, Peter, Landsea, Chris W., Lankhorst, Matthias, Lavado-Casimiro, Waldo, Lazzara, Matthew A., Lee, S. E., Lee, T. C., Leuliette, Eric, L'Heureux, Michelle, Li, Tim, Lieser, Jan L., Lin, I. I., Mears, Carl A., Liu, Gang, Li, Bailing, Liu, Hongxing, Locarnini, Ricardo, Loeb, Norman G., Long, Craig S., López, Luis A., Lorrey, Andrew M., Loyola, Diego, Lumpkin, Rick, Luo, Jing Jia, Luojus, K., Luthcke, S., Macias-Fauria, M., Malkova, G. V., Manney, Gloria L., Marcellin, Vernie, Marchenko, S. S., Marengo, José A., Marín, Dora, Marra, John J., Marszelewski, Wlodzimierz, Martens, B., Martin, A., Martínez, Alejandra G., Martínez-Güingla, Rodney, Martínez-Sánchez, Odalys, Marsh, Benjamin L., Lyman, John M., Massom, Robert A., May, Linda, Mayer, Michael, Mazloff, Matthew, McBride, Charlotte, McCabe, M. F., McCarthy, Mark, Meier, W., Meijers, Andrew J.S., Mekonnen, Ademe, Mengistu Tsidu, G., Menzel, W. Paul, Merchant, Christopher J., Meredith, Michael P., Merrifield, Mark A., Miller, Ben, Miralles, Diego G., Mitchum, Gary T., Mitro, Sukarni, Moat, Ben, Mochizuki, Y., Monselesan, Didier, Montzka, Stephen A., Mora, Natalie, Morice, Colin, Mosquera-Vásquez, Kobi, Mostafa, Awatif E., Mote, T., Mudryk, L., Mühle, Jens, Mullan, A. Brett, Müller, Rolf, Myneni, R., Nash, Eric R., Nerem, R. Steven, Newman, L., Newman, Paul A., Nielsen-Gammon, John W., Nieto, Juan José, Noetzli, Jeannette, Noll, Ben E., O'Neel, S., Osborn, Tim J., Osborne, Emily, Overland, J., Oyunjargal, Lamjav, Park, T., Pasch, Richard J., Pascual-Ramírez, Reynaldo, Pastor Saavedra, Maria Asuncion, Paterson, Andrew M., Paulik, Christoph, Pearce, Petra R., Peltier, Alexandre, Pelto, Mauri S., Peng, Liang, Perkins-Kirkpatrick, Sarah E., Perovich, Don, Petropavlovskikh, Irina, Pezza, Alexandre B., Phillips, C., Phillips, David, Phoenix, G., Pinty, Bernard, Pinzon, J., Po-Chedley, S., Polashenski, C., Purkey, Sarah G., Quispe, Nelson, Rajeevan, Madhavan, Rakotoarimalala, C., Rayner, Darren, Raynolds, M. K., Reagan, James, Reid, Phillip, Reimer, Christoph, Rémy, Samuel, Revadekar, Jayashree V., Richardson, A. D., Richter-Menge, Jacqueline, Ricker, R., Rimmer, Alon, Robinson, David A., Rodell, Matthew, Rodriguez Camino, Ernesto, Romanovsky, Vladimir E., Ronchail, Josyane, Rosenlof, Karen H., Rösner, Benjamin, Roth, Chris, Roth, David Mark, Rusak, James A., Rutishäuser, T., Sallée, Jean Bapiste, Sánchez-Lugo, Ahira, Santee, Michelle L., Sasgen, L., Sawaengphokhai, P., Sayad, T. A., Sayouri, Amal, Scambos, Ted A., Scanlon, T., Schenzinger, Verena, Schladow, S. Geoffrey, Schmid, Claudia, Schmid, Martin, Schreck, Carl J., Selkirk, H. B., Send, Uwe, Sensoy, Serhat, Sharp, M., Shi, Lei, Shiklomanov, Nikolai I., Shimaraeva, Svetlana V., Siegel, David A., Silow, Eugene, Sima, Fatou, Simmons, Adrian J., Skirving, William J., Smeed, David A., Smeets, C. J.P.P., Smith, Adam, Smith, Sharon L., Soden, B., Sofieva, Viktoria, Sparks, T. H., Spence, Jacqueline M., Spillane, Sandra, Srivastava, A. K., Stackhouse, Paul W., Stammerjohn, Sharon, Stanitski, Diane M., Steinbrecht, Wolfgang, Stella, José L., Stengel, M., Stephenson, Kimberly, Stephenson, Tannecia S., Strahan, Susan, Streletskiy, Dimitri A., Strong, Alan E., Sun-Mack, Sunny, Sutton, Adrienne J., Swart, Sebastiaan, Sweet, William, Takahashi, Kenneth S., Tamar, Gerard, Taylor, Michael A., Tedesco, M., Thackeray, S. J., Thoman, R. L., Thompson, Philip, Thomson, L., Thorsteinsson, T., Timbal, Bertrand, Timmermans, M. L., TImofeyev, Maxim A., Tirak, Kyle V., Tobin, Skie, Togawa, H., Tømmervik, H., Tourpali, Kleareti, Trachte, Katja, Trewin, Blair C., Triñanes, Joaquin A., Trotman, Adrian R., Tschudi, M., Tucker, C. J., Tye, Mari R., Van As, D., Van De Wal, R. S.W., Van Der Ronald, J. A., Van Der Schalie, Robin, Van Der Schrier, Gerard, Van Der Werf, Guido R., Van Meerbeeck, Cedric J., Velden, Christopher S., Velicogna, I., Verburg, Piet, Vickers, H., Vincent, Lucie A., Vömel, Holger, Vose, Russell S., Wagner, Wolfgang, Walker, D. A., Walsh, J., Wang, Bin, Wang, Junhong, Wang, Lei, Wang, M., Wang, Ray, Wang, Sheng Hung, Wanninkhof, Rik, Watanabe, Shohei, Weber, Mark, Webster, M., Weller, Robert A., Westberry, Toby K., Weyhenmeyer, Gesa A., Whitewood, Robert, Widlansky, Matthew J., Wiese, David N., Wijffels, Susan E., Wilber, Anne C., Wild, Jeanette D., Willett, Kate M., Willis, Josh K., Wolken, G., Wong, Takmeng, Wood, E. F., Wood, K., Woolway, R. Iestyn, Wouters, B., Xue, Yan, Yin, Xungang, Yoon, Huang, York, A., Yu, Lisan, Zambrano, Eduardo, Zhang, Huai Min, Zhang, Peiqun, Zhao, Guanguo, Zhao, Lin, Zhu, Zhiwei, Ziel, R., Ziemke, Jerry R., Ziese, Markus G., Griffin, Jessicca, Hammer, Gregory, Love-Brotak, S. Elizabeth, Misch, Deborah J., Riddle, Deborah B., Slagle, Mary, Sprain, Mara, Veasey, Sara W., McVicar, Tim R., Sub Dynamics Meteorology, Sub Soft Condensed Matter, LS Religiewetenschap, Sub Atmospheric physics and chemistry, Zonder bezoldiging NED, LS Taalverwerving, Leerstoel Tubergen, Afd Chemical Biology and Drug Discovery, Hafd Faculteitsbureau GW, Afd Pharmacology, Dep IRAS, Marine and Atmospheric Research, OFR - Religious Studies, Abernethy, R., Ackerman, Steven A., Adler, R., Albanil Encarnación, Adelina, Aldeco, Laura S., Alfaro, Eric J., Aliaga-Nestares, Vannia, Allan, Richard P., Allan, Rob, Alves, Lincoln M., Amador, Jorge A., Anderson, John, Andreassen, L. M., Argüez, Anthony, Armitage, C., Arndt, Derek S., Avalos, Grinia, Azorin-Molina, César, Báez, Julián, Bardin, M. Yu, Barichivich, Jonathan, Baringer, Molly O., Barreira, Sandra, Baxter, Stephen, Beck, H. E., Becker, Andreas, Bedka, Kristopher M., Behe, Carolina, Bell, Gerald D., Bellouin, Nicolas, Belmont, M., Benedetti, Angela, Bernhard, G. H., Berrisford, Paul, Berry, David I., Bhatt, U. S., Bissolli, Peter, Bjerke, J., Blake, Eric S., Blenkinsop, Stephen, Blunden, Jessica, Bolmgren, K., Bosilovich, Michael G., Boucher, Olivier, Bouchon, Marilú, Box, J. E., Boyer, Tim, Braathen, Geir O., Bromwich, David H., Brown, R., Buehler, S., Bulygina, Olga N., Burgess, D., Calderón, Blanca, Camargo, Suzana J., Campbell, Ethan C., Campbell, Jayaka D., Cappelen, J., Carrea, Laura, Carter, Brendan R., Castro, Anabel, Chambers, Don P., Cheng, Lijing, Christiansen, Hanne H., Christy, John R., Chung, E. S., Clem, Kyle R., Coelho, Caio A.S., Coldewey-Egbers, Melanie, Colwell, Steve, Cooper, Owen R., Copland, L., Costanza, Carol, Covey, Curt, Coy, Lawrence, Cronin, T., Crouch, Jake, Cruzado, Luis, Daniel, Raychelle, Davis, Sean M., Davletshin, S. G., De Eyto, Elvira, De Jeu, Richard A.M., De La Cour, Jacqueline L., De Laat, Jos, De Gasperi, Curtis L., Degenstein, Doug, Deline, P., Demircan, Mesut, Derksen, C., Dewitte, Boris, Dhurmea, R., Di Girolamo, Larry, Diamond, Howard J., Dickerson, C., Dlugokencky, Ed J., Dohan, Kathleen, Dokulil, Martin T., Dolman, A. Johannes, Domingues, Catia M., Domingues, Ricardo, Donat, Markus G., Dong, Shenfu, Dorigo, Wouter A., Drozdov, D. S., Dunn, Robert J.H., Durre, Imke, Dutton, Geoff S., Eakin, C. Mark, El Kharrim, M., Elkins, James W., Epstein, H. E., Espinoza, Jhan C., Famiglietti, James S., Farmer, J., Farrell, S., Fauchald, P., Fausto, R. S., Feely, Richard A., Feng, Z., Fenimore, Chris, Fettweis, X., Fioletov, Vitali E., Flemming, Johannes, Fogt, Ryan L., Folland, Chris, Forbes, B. C., Foster, Michael J., Francis, S. D., Franz, Bryan A., Frey, Richard A., Frith, Stacey M., Froidevaux, Lucien, Ganter, Catherine, Geiger, Erick F., Gerland, S., Gilson, John, Gobron, Nadine, Goldenberg, Stanley B., Gomez, Andrea M., Goni, Gustavo, Grooß, Jens Uwe, Gruber, Alexander, Guard, Charles P., Gugliemin, Mario, Gupta, S. K., Gutiérrez, Dimitri, Haas, C., Hagos, S., Hahn, Sebastian, Haimberger, Leo, Hall, Brad D., Halpert, Michael S., Hamlington, Benjamin D., Hanna, E., Hansen, K., Hanssen-Bauer, L., Harris, Ian, Hartfield, Gail, Heidinger, Andrew K., Heim, Richard R., Helfrich, S., Hemming, D. L., Hendricks, S., Hernández, Rafael, Hernández, Sosa Marieta, Heron, Scott F., Heuzé, C., Hidalgo, Hugo G., Ho, Shu Peng, Hobbs, William R., Horstkotte, T., Huang, Boyin, Hubert, Daan, Hueuzé, Céline, Hurst, Dale F., Ialongo, Iolanda, Ibrahim, M. M., Ijampy, J. A., Inness, Antje, Isaac, Victor, Isaksen, K., Ishii, Masayoshi, Jacobs, Stephanie J., Jeffries, Martin O., Jevrejeva, Svetlana, Jiménez, C., Jin, Xiangze, John, Viju, Johns, William E., Johnsen, Bjørn, Johnson, Bryan, Johnson, Gregory C., Johnson, Kenneth S., Jones, Philip D., Jumaux, Guillaume, Kabidi, Khadija, Kaiser, J. W., Karaköylü, Erdem M., Kato, Seiji, Kazemi, A., Keller, Linda M., Kennedy, John, Kerr, Kenneth, Khan, M. S., Kholodov, A. L., Khoshkam, Mahbobeh, Killick, Rachel, Kim, Hyungjun, Kim, S. J., Klotzbach, Philip J., Knaff, John A., Kohler, J., Korhonen, Johanna, Korshunova, Natalia N., Kramarova, Natalya, Kratz, D. P., Kruger, Andries, Kruk, Michael C., Krumpen, T., Ladd, C., Lakatos, Mónika, Lakkala, Kaisa, Lander, Mark A., Landschützer, Peter, Landsea, Chris W., Lankhorst, Matthias, Lavado-Casimiro, Waldo, Lazzara, Matthew A., Lee, S. E., Lee, T. C., Leuliette, Eric, L'Heureux, Michelle, Li, Tim, Lieser, Jan L., Lin, I. I., Mears, Carl A., Liu, Gang, Li, Bailing, Liu, Hongxing, Locarnini, Ricardo, Loeb, Norman G., Long, Craig S., López, Luis A., Lorrey, Andrew M., Loyola, Diego, Lumpkin, Rick, Luo, Jing Jia, Luojus, K., Luthcke, S., Macias-Fauria, M., Malkova, G. V., Manney, Gloria L., Marcellin, Vernie, Marchenko, S. S., Marengo, José A., Marín, Dora, Marra, John J., Marszelewski, Wlodzimierz, Martens, B., Martin, A., Martínez, Alejandra G., Martínez-Güingla, Rodney, Martínez-Sánchez, Odalys, Marsh, Benjamin L., Lyman, John M., Massom, Robert A., May, Linda, Mayer, Michael, Mazloff, Matthew, McBride, Charlotte, McCabe, M. F., McCarthy, Mark, Meier, W., Meijers, Andrew J.S., Mekonnen, Ademe, Mengistu Tsidu, G., Menzel, W. Paul, Merchant, Christopher J., Meredith, Michael P., Merrifield, Mark A., Miller, Ben, Miralles, Diego G., Mitchum, Gary T., Mitro, Sukarni, Moat, Ben, Mochizuki, Y., Monselesan, Didier, Montzka, Stephen A., Mora, Natalie, Morice, Colin, Mosquera-Vásquez, Kobi, Mostafa, Awatif E., Mote, T., Mudryk, L., Mühle, Jens, Mullan, A. Brett, Müller, Rolf, Myneni, R., Nash, Eric R., Nerem, R. Steven, Newman, L., Newman, Paul A., Nielsen-Gammon, John W., Nieto, Juan José, Noetzli, Jeannette, Noll, Ben E., O'Neel, S., Osborn, Tim J., Osborne, Emily, Overland, J., Oyunjargal, Lamjav, Park, T., Pasch, Richard J., Pascual-Ramírez, Reynaldo, Pastor Saavedra, Maria Asuncion, Paterson, Andrew M., Paulik, Christoph, Pearce, Petra R., Peltier, Alexandre, Pelto, Mauri S., Peng, Liang, Perkins-Kirkpatrick, Sarah E., Perovich, Don, Petropavlovskikh, Irina, Pezza, Alexandre B., Phillips, C., Phillips, David, Phoenix, G., Pinty, Bernard, Pinzon, J., Po-Chedley, S., Polashenski, C., Purkey, Sarah G., Quispe, Nelson, Rajeevan, Madhavan, Rakotoarimalala, C., Rayner, Darren, Raynolds, M. K., Reagan, James, Reid, Phillip, Reimer, Christoph, Rémy, Samuel, Revadekar, Jayashree V., Richardson, A. D., Richter-Menge, Jacqueline, Ricker, R., Rimmer, Alon, Robinson, David A., Rodell, Matthew, Rodriguez Camino, Ernesto, Romanovsky, Vladimir E., Ronchail, Josyane, Rosenlof, Karen H., Rösner, Benjamin, Roth, Chris, Roth, David Mark, Rusak, James A., Rutishäuser, T., Sallée, Jean Bapiste, Sánchez-Lugo, Ahira, Santee, Michelle L., Sasgen, L., Sawaengphokhai, P., Sayad, T. A., Sayouri, Amal, Scambos, Ted A., Scanlon, T., Schenzinger, Verena, Schladow, S. Geoffrey, Schmid, Claudia, Schmid, Martin, Schreck, Carl J., Selkirk, H. B., Send, Uwe, Sensoy, Serhat, Sharp, M., Shi, Lei, Shiklomanov, Nikolai I., Shimaraeva, Svetlana V., Siegel, David A., Silow, Eugene, Sima, Fatou, Simmons, Adrian J., Skirving, William J., Smeed, David A., Smeets, C. J.P.P., Smith, Adam, Smith, Sharon L., Soden, B., Sofieva, Viktoria, Sparks, T. H., Spence, Jacqueline M., Spillane, Sandra, Srivastava, A. K., Stackhouse, Paul W., Stammerjohn, Sharon, Stanitski, Diane M., Steinbrecht, Wolfgang, Stella, José L., Stengel, M., Stephenson, Kimberly, Stephenson, Tannecia S., Strahan, Susan, Streletskiy, Dimitri A., Strong, Alan E., Sun-Mack, Sunny, Sutton, Adrienne J., Swart, Sebastiaan, Sweet, William, Takahashi, Kenneth S., Tamar, Gerard, Taylor, Michael A., Tedesco, M., Thackeray, S. J., Thoman, R. L., Thompson, Philip, Thomson, L., Thorsteinsson, T., Timbal, Bertrand, Timmermans, M. L., TImofeyev, Maxim A., Tirak, Kyle V., Tobin, Skie, Togawa, H., Tømmervik, H., Tourpali, Kleareti, Trachte, Katja, Trewin, Blair C., Triñanes, Joaquin A., Trotman, Adrian R., Tschudi, M., Tucker, C. J., Tye, Mari R., Van As, D., Van De Wal, R. S.W., Van Der Ronald, J. A., Van Der Schalie, Robin, Van Der Schrier, Gerard, Van Der Werf, Guido R., Van Meerbeeck, Cedric J., Velden, Christopher S., Velicogna, I., Verburg, Piet, Vickers, H., Vincent, Lucie A., Vömel, Holger, Vose, Russell S., Wagner, Wolfgang, Walker, D. A., Walsh, J., Wang, Bin, Wang, Junhong, Wang, Lei, Wang, M., Wang, Ray, Wang, Sheng Hung, Wanninkhof, Rik, Watanabe, Shohei, Weber, Mark, Webster, M., Weller, Robert A., Westberry, Toby K., Weyhenmeyer, Gesa A., Whitewood, Robert, Widlansky, Matthew J., Wiese, David N., Wijffels, Susan E., Wilber, Anne C., Wild, Jeanette D., Willett, Kate M., Willis, Josh K., Wolken, G., Wong, Takmeng, Wood, E. F., Wood, K., Woolway, R. Iestyn, Wouters, B., Xue, Yan, Yin, Xungang, Yoon, Huang, York, A., Yu, Lisan, Zambrano, Eduardo, Zhang, Huai Min, Zhang, Peiqun, Zhao, Guanguo, Zhao, Lin, Zhu, Zhiwei, Ziel, R., Ziemke, Jerry R., Ziese, Markus G., Griffin, Jessicca, Hammer, Gregory, Love-Brotak, S. Elizabeth, Misch, Deborah J., Riddle, Deborah B., Slagle, Mary, Sprain, Mara, Veasey, Sara W., and McVicar, Tim R.

Published
2018

27. Antarctic pack ice algal distribution: Floe-scale spatial variability and predictability from physical parameters

Author

Meiners, K. M., Arndt, S., Bestley, S., Krumpen, T., Ricker, R., Milnes, M., Newbery, K., Freier, U., Jarman, S., King, R., Proud, R., Kawaguchi, S., Meyer, B., Laboratoire d'Océanographie Physique et Spatiale (LOPS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), University of St Andrews. School of Biology, University of St Andrews. Scottish Oceans Institute, and University of St Andrews. Pelagic Ecology Research Group

Subjects
GE, biomass, QH301 Biology, chlorophyll a, DAS, snow, Sea-ice properties, QH301, ice algae, [SDU]Sciences of the Universe [physics], freeboard, sea ice properties, Chlorophyll-a, GE Environmental Sciences
Abstract

This study was supported by the PACES (Polar Regions and Coasts in a changing Earth System) program (Topic 1, WP 5) of the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, the Helmholtz Virtual Institute „PolarTime“ (VH-VI-500: Biological timing in a changing marine environment — clocks and rhythms in polar pelagic organisms), the Helmholtz Alliance “Remote Sensing and Earth System Dynamics” (HA-310); and by the Australian Government through i) Australian Antarctic Science projects (4073, 4298), ii) the Cooperative Research Centres Programme through the Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC), and iii) the Antarctic Gateway Partnership special research initiative through the Australian Research Council. All data used in this study are available through the Australian Antarctic Data Centre as well as PANGAEA (doi.pangaea.de/10.1594/PANGAEA.870706). Antarctic pack ice serves as habitat for microalgae which contribute to Southern Ocean primary production and serve as important food source for pelagic herbivores. Ice algal biomass is highly patchy, and remains severely undersampled by classical methods such as spatially restricted ice-coring surveys. Here we provide an unprecedented view of ice algal biomass distribution, mapped (as chlorophyll-a) in a 100m-by-100m area of a Weddell Sea pack-ice floe, using under-ice irradiance measurements taken with an instrumented Remotely Operated Vehicle. We identified significant correlations (p

Published
2017

30. The winter pack-ice zone provides a sheltered but food-poor habitat for larval Antarctic krill

Author

Meyer, B., Freier, U., Grimm, Volker, Groeneveld, J., Hunt, B.P.V., Kerwath, S., King, R., Klaas, C., Pakhomov, E., Meiners, K.M., Melbourne-Thomas, J., Murphy, E.J., Thorpe, S.E., Stammerjohn, S., Wolf-Gladrow, D., Auerswald, L., Götz, A., Halbach, L., Jarman, S., Kawaguchi, S., Krumpen, T., Nehrke, G., Ricker, R., Sumner, M., Teschke, M., Trebilco, R., Yilmaz, N.I., Meyer, B., Freier, U., Grimm, Volker, Groeneveld, J., Hunt, B.P.V., Kerwath, S., King, R., Klaas, C., Pakhomov, E., Meiners, K.M., Melbourne-Thomas, J., Murphy, E.J., Thorpe, S.E., Stammerjohn, S., Wolf-Gladrow, D., Auerswald, L., Götz, A., Halbach, L., Jarman, S., Kawaguchi, S., Krumpen, T., Nehrke, G., Ricker, R., Sumner, M., Teschke, M., Trebilco, R., and Yilmaz, N.I.

Abstract

A dominant Antarctic ecological paradigm suggests that winter sea ice is generally the main feeding ground for krill larvae. Observations from our winter cruise to the southwest Atlantic sector of the Southern Ocean contradict this view and present the first evidence that the pack-ice zone is a food-poor habitat for larval development. In contrast, the more open marginal ice zone provides a more favourable food environment for high larval krill growth rates. We found that complex under-ice habitats are, however, vital for larval krill when water column productivity is limited by light, by providing structures that offer protection from predators and to collect organic material released from the ice. The larvae feed on this sparse ice-associated food during the day. After sunset, they migrate into the water below the ice (upper 20 m) and drift away from the ice areas where they have previously fed. Model analyses indicate that this behaviour increases both food uptake in a patchy food environment and the likelihood of overwinter transport to areas where feeding conditions are more favourable in spring.

Published
2017

31. Antarctic pack ice algal distribution: Floe-scale spatial variability and predictability from physical parameters

Author

Meiners, K., Arndt, S., Bestley, S., Krumpen, T., Ricker, R., Milnes, M., Newbery, K., Freier, U., Jarman, Simon, King, R., Proud, R., Kawaguchi, S., Meyer, B., Meiners, K., Arndt, S., Bestley, S., Krumpen, T., Ricker, R., Milnes, M., Newbery, K., Freier, U., Jarman, Simon, King, R., Proud, R., Kawaguchi, S., and Meyer, B.

Abstract

©2017. Commonwealth of Australia. Antarctic pack ice serves as habitat for microalgae which contribute to Southern Ocean primary production and serve as important food source for pelagic herbivores. Ice algal biomass is highly patchy and remains severely undersampled by classical methods such as spatially restricted ice coring surveys. Here we provide an unprecedented view of ice algal biomass distribution, mapped (as chlorophyll a) in a 100 m by 100 m area of a Weddell Sea pack ice floe, using under-ice irradiance measurements taken with an instrumented remotely operated vehicle. We identified significant correlations (p < 0.001) between algal biomass and concomitant in situ surface measurements of snow depth, ice thickness, and estimated sea ice freeboard levels using a statistical model. The model's explanatory power (r2 = 0.30) indicates that these parameters alone may provide a first basis for spatial prediction of ice algal biomass, but parameterization of additional determinants is needed to inform more robust upscaling efforts.

Published
2017

32. Online sea-ice knowledge and data platform

Author

Grosfeld, K., Treffeisen, R., Asseng, J., Bartsch, A., Bräuer, B., Fritzsch, B., Gerdes, R., Hendricks, S., Hiller, W., Heygster, G., Krumpen, T., Lemke, P., Melsheimer, C., Nicolaus, M., Ricker, R., and Weigelt, M.

Subjects
Earth sciences and geology, Earth Science
Abstract

The combination of multi-disciplinary sea ice science and the rising demand of society for up-to-date information and user customized products on climate change emphasis the need for addressing the challenges posed by environmental change in the Polar Regions by means of creating new ways of communication. The new knowledge platform “meereisportal.de” is a contribution to the cross-linking of scientifically qualified information on climate change and focuses deliberately on the theme: “sea ice” in both Polar Regions. With “meereisportal. de” the science opens to changing societal demands and goes new ways of communication between science and society. “meereisportal. de” is the first comprehensive German speaking knowledge platform on sea ice that went online 2013. It was developed in the frame of the Helmholtz Climate Initiative, Regional Climate Change (REKLIM) as a joint project of the University of Bremen (Institute of Environmental Physics) and the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research under the management of the Helmholtz Regional Climate Office for Polar Regions and Sea Level change. This paper describes the concept and the development of the knowledge platform, different usage examples and user-specific products. Moreover, an outlook on the planned activities in the future will be given. Die Kombination der zunehmend multi-disziplinären Meereisforschung und die steigende Nachfrage der Gesellschaft nach aktuellen Informationen und benutzerorientierten Produkten zum Thema Klimawandel erfordert neue Wege der Wissenskommunikation, um den Herausforderungen der zunehmenden Umweltveränderungen, insbesondere in den Polarregionen, zu begegnen. Die neue Wissensplattform “meereisportal.de” ist ein Beitrag zum Vernetzen von wissenschaftlich qualifizierten Fachinformationen zum Thema Klimawandel und fokussiert dabei bewusst auf ein Thema: “Meereis” in beiden Polargebieten. Mit “meereisportal.de” öffnet sich die Wissenschaft gegenüber sich verändernden gesellschaftlichen Anforderungen und geht neue Wege der Kommunikation zwischen Wissenschaft und Gesellschaft. “meereisportal. de” ist 2013 als erste umfassende, deutschsprachige Wissensplattform rund um das Thema Meereis in der Arktis und Antarktis online gegangen. Sie wurde im Rahmen des Helmholtz-Verbundes Regionale Klimaveränderungen (REKLIM) als Gemeinschaftsprojekt der Universität Bremen (Institut für Umweltphysik) und des Alfred-Wegener-Institutes, Helmholtz-Zentrum für Polar- und Meeresforschung unter der Federführung des regionalen Helmholtz Klimabüros für Polargebiete und Meeresspiegelanstieg entwickelt. Dieser Beitrag beschreibt die Entstehung, das Konzept und die Entwicklung der Wissensplattform, verschiedene Anwendungsbeispiele sowie nutzerspezifische Produkte. Darüber hinaus wird ein Ausblick über die in Zukunft geplanten Aktivitäten gegeben.

Published
2016
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34. Online sea ice knowledge and data platform: www.meereisportal.de

Author

Treffeisen, R., Asseng, J., Bartsch, A., Bräuer, B., Fritzsch, B., Grosfeld, K., Hendricks, S., Hiller, W., Heygster, G., Krumpen, T., Melsheimer, C., Nicolaus, M., Ricker, R., Weigelt, M., Treffeisen, R., Asseng, J., Bartsch, A., Bräuer, B., Fritzsch, B., Grosfeld, K., Hendricks, S., Hiller, W., Heygster, G., Krumpen, T., Melsheimer, C., Nicolaus, M., Ricker, R., and Weigelt, M.

Published
2015

42. SEASONALITY OF SEA ICE PROPERTIES FROM AUTONOMOUS MEASUREMENTS.

Author

Nicolaus, Marcel, Bartsch, A., Grosfeld, K., Hendricks, S., Heygster, G., Kaleschke, L., Melsheimer, C., Ricker, R., Schwegmann, S., and Treffeisen, R.

Abstract

An abstract of the article "Seasonality of Sea Ice Properties From Autonomous Measurements," by Marcel Nicolaus is presented.

Published
2015

43. Rapid and label-free influenza A virus subtyping using surface-enhanced Raman spectroscopy with incident-wavelength analysis.

Author

Ricker R, Perea Lopez N, Terrones M, Loew M, and Ghedin E

Abstract

Early virus identification is a key component of both patient treatment and epidemiological monitoring. In the case of influenza A virus infections, where the detection of subtypes associated with bird flu in humans could lead to a pandemic, rapid subtype-level identification is important. Surface-enhanced Raman spectroscopy coupled with machine learning can be used to rapidly detect and identify viruses in a label-free manner. As there is a range of available excitation wavelengths for performing Raman spectroscopy, we must choose the best one to permit discrimination between highly similar subtypes of a virus. We show that the spectra produced by influenza A subtypes H1N1 and H3N2 exhibit a higher degree of dissimilarity when using 785 nm excitation wavelength in comparison with 532 nm excitation wavelength. Furthermore, the cross-validated area under the curve (AUC) for identification was higher for the 785 nm excitation, reaching 0.95 as compared to 0.86 for 532 nm. Ultimately, this study suggests that exciting with a 785 nm wavelength is better able to differentiate two closely related influenza viruses and likely can extend to other closely related pathogens., Competing Interests: N.P.L. and M.T. hold equity in Virolock Technologies LLC; a company engaged in the commercialization of virus enrichment using carbon nanotube arrays., (© 2024 Optica Publishing Group.)

Published
2024
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44. Phosphine-Catalyzed 1,2-cis-Diboration of 1,3-Butadiynes.

Author

Li W, Ricker R, Lok Chan K, Fung Lau P, Buchbinder NW, Krebs J, Friedrich A, Lin Z, Santos WL, Radius U, and Marder TB

Abstract

Trialkyl phosphines PMe 3 and PEt 3 catalyze the 1,2-cis-diboration of 1,3-butadiynes to give 1,2-diboryl enynes. The products were utilized to synthesize 1,1,2,4-tetraaryl enynes using a Suzuki-Miyaura protocol and can readily undergo proto-deborylation., (© 2024 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

Published
2024
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45. Digital elevation models of the sea-ice surface from airborne laser scanning during MOSAiC.

Author

Hutter N, Hendricks S, Jutila A, Ricker R, von Albedyll L, Birnbaum G, and Haas C

Abstract

Airborne laser scanners (ALS) are used to map the sea-ice surface at sub-meter resolution. We conducted 64 flights over the Arctic sea ice between September 2019 and September 2020 during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition to measure sea-ice surface elevation. The flights ranged from repeated, local-scale 5 × 5 km 2 floe grid surveys to regional-scale transects more than 100 km long. We provide data at different processing levels: geolocated elevation point clouds and gridded segments of elevation and freeboard with a spatial resolution of 0.5 m. The latter product is corrected for atmospheric backscatter, sea-ice drift, and offset in elevation due to degraded INS/GNSS solutions > 85° N. For floe grid surveys, all data are combined to merged two-dimensional elevation maps. Other provided parameters include laser reflectance and echo width. The presented data offer a unique possibility to study the temporal evolution, spatial distribution, and variability of the snow and sea-ice surface and their properties in addition to validating satellite products., (© 2023. Springer Nature Limited.)

Published
2023
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46. Helicopter-borne RGB orthomosaics and photogrammetric digital elevation models from the MOSAiC Expedition.

Author

Neckel N, Fuchs N, Birnbaum G, Hutter N, Jutila A, Buth L, von Albedyll L, Ricker R, and Haas C

Abstract

The Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition took place between October 2019 and September 2020 giving the rare opportunity to monitor sea-ice properties over a full annual cycle. Here we present 24 high-resolution orthomosaics and 14 photogrammetric digital elevation models of the sea-ice surface around the icebreaker RV Polarstern between March and September 2020. The dataset is based on >34.000 images acquired by a helicopter-borne optical camera system with survey flights covering areas between 1.8 and 96.5 km 2 around the vessel. Depending on the flight pattern and altitude of the helicopter, ground resolutions of the orthomosaics range between 0.03 and 0.5 m. By combining the photogrammetric products with contemporaneously acquired airborne laser scanner reflectance measurements selected orthomosaics could be corrected for cloud shadows which facilitates their usage for sea-ice and melt pond classification algorithms. The presented dataset is a valuable data source for the interdisciplinary MOSAiC community building a temporal and spatially resolved baseline to accompany various remote sensing and in situ research projects., (© 2023. The Author(s).)

Published
2023
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47. Transition Metal-Free Regio- and Stereo-Selective trans Hydroboration of 1,3-Diynes: A Phosphine-Catalyzed Access to (E)-1-Boryl-1,3-Enynes.

Author

Jos S, Szwetkowski C, Slebodnick C, Ricker R, Chan KL, Chan WC, Radius U, Lin Z, Marder TB, and Santos WL

Abstract

We report a transition metal-free, regio- and stereo-selective, phosphine-catalyzed method for the trans hydroboration of 1,3-diynes with pinacolborane that affords (E)-1-boryl-1,3-enynes. The reaction proceeds with excellent selectivity for boron addition to the external carbon of the 1,3-diyne framework as unambiguously established by NMR and X-ray crystallographic studies. The reaction displays a broad substrate scope including unsymmetrical diynes to generate products in high yield (up to 95 %). Experimental and theoretical studies suggest that phosphine attack on the alkyne is a key process in the catalytic cycle., (© 2022 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

Published
2022
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48. Sea ice surface temperatures from helicopter-borne thermal infrared imaging during the MOSAiC expedition.

Author

Thielke L, Huntemann M, Hendricks S, Jutila A, Ricker R, and Spreen G

Abstract

The sea ice surface temperature is important to understand the Arctic winter heat budget. We conducted 35 helicopter flights with an infrared camera in winter 2019/2020 during the Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. The flights were performed from a local, 5 to 10 km scale up to a regional, 20 to 40 km scale. The infrared camera recorded thermal infrared brightness temperatures, which we converted to surface temperatures. More than 150000 images from all flights can be investigated individually. As an advanced data product, we created surface temperature maps for every flight with a 1 m resolution. We corrected image gradients, applied an ice drift correction, georeferenced all pixels, and corrected the surface temperature by its natural temporal drift, which results in time-fixed surface temperature maps for a consistent analysis of one flight. The temporal and spatial variability of sea ice characteristics is an important contribution to an increased understanding of the Arctic heat budget and, in particular, for the validation of satellite products., (© 2022. The Author(s).)

Published
2022
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49. Accurate virus identification with interpretable Raman signatures by machine learning.

Author

Ye J, Yeh YT, Xue Y, Wang Z, Zhang N, Liu H, Zhang K, Ricker R, Yu Z, Roder A, Perea Lopez N, Organtini L, Greene W, Hafenstein S, Lu H, Ghedin E, Terrones M, Huang S, and Huang SX

Subjects
Disease Outbreaks, Pandemics, Serogroup, Machine Learning, Neural Networks, Computer, Viruses classification
Abstract

Rapid identification of newly emerging or circulating viruses is an important first step toward managing the public health response to potential outbreaks. A portable virus capture device, coupled with label-free Raman spectroscopy, holds the promise of fast detection by rapidly obtaining the Raman signature of a virus followed by a machine learning (ML) approach applied to recognize the virus based on its Raman spectrum, which is used as a fingerprint. We present such an ML approach for analyzing Raman spectra of human and avian viruses. A convolutional neural network (CNN) classifier specifically designed for spectral data achieves very high accuracy for a variety of virus type or subtype identification tasks. In particular, it achieves 99% accuracy for classifying influenza virus type A versus type B, 96% accuracy for classifying four subtypes of influenza A, 95% accuracy for differentiating enveloped and nonenveloped viruses, and 99% accuracy for differentiating avian coronavirus (infectious bronchitis virus [IBV]) from other avian viruses. Furthermore, interpretation of neural net responses in the trained CNN model using a full-gradient algorithm highlights Raman spectral ranges that are most important to virus identification. By correlating ML-selected salient Raman ranges with the signature ranges of known biomolecules and chemical functional groups—for example, amide, amino acid, and carboxylic acid—we verify that our ML model effectively recognizes the Raman signatures of proteins, lipids, and other vital functional groups present in different viruses and uses a weighted combination of these signatures to identify viruses.

Published
2022
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50. Co-composting of biochar and nitrogen-poor organic residues: Nitrogen losses and fate of polycyclic aromatic hydrocarbons.

Author

Gustavo Adolfo GF, Wolf-Anno B, Martin R, and Christina S

Subjects
Charcoal chemistry, Nitrogen analysis, Soil chemistry, Composting, Polycyclic Aromatic Hydrocarbons chemistry
Abstract

Composting recycles nutrients and biodegrades organic pollutants, but often results in N leaching. Biochar can enhance the composting process and reduce N losses. Research, however, has focused on composting N-rich residues; also, information on the fate of biochar polycyclic aromatic hydrocarbons (PAHs) during composting is scarce. We explored the composting of biochar with N-poor organic residues as a strategy to reduce N losses and biochar PAHs. A small-scale composting experiment was performed with three treatments: 100% yard residues and two mixtures of 85% yard residues and 15% gasification- or pyrolysis-derived biochar. Temperatures were recorded daily during composting and Nlosses and changes in PAHs loads were calculated. Results across all treatments showed overall low N losses, likely caused by low temperatures and N contents, circumneutral pH values, and absence of leachate, and simultaneous immobilization and mineralization of PAH contents. Treatments with biochar showed a slower release of inorganic N (NO 3 --N and NH 4 + -N), although they also had overall lower inorganic N contents. This slower release of inorganic N may relate to biochar's high surface area. We conclude that biochar provides valuable benefits for N-poor composting, and that composting should be further explored as a promising strategy to reduce the contents of PAHs in biochar., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Published
2022
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