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174 results on '"Tourpali, K."'

1. Recent variability of the solar spectral irradiance and its impact on climate modelling

Author

Ermolli, I., Matthes, K., de Wit, T. Dudok, Krivova, N. A., Tourpali, K., Weber, M., Unruh, Y. C., Gray, L., Langematz, U., Pilewskie, P., Rozanov, E., Schmutz, W., Shapiro, A., Solanki, S. K., and Woods, T. N.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Physics - Atmospheric and Oceanic Physics
Abstract

The lack of long and reliable time series of solar spectral irradiance (SSI) measurements makes an accurate quantification of solar contributions to recent climate change difficult. Whereas earlier SSI observations and models provided a qualitatively consistent picture of the SSI variability, recent measurements by the SORCE satellite suggest a significantly stronger variability in the ultraviolet (UV) spectral range and changes in the visible and near-infrared (NIR) bands in anti-phase with the solar cycle. A number of recent chemistry-climate model (CCM) simulations have shown that this might have significant implications on the Earth's atmosphere. Motivated by these results, we summarize here our current knowledge of SSI variability and its impact on Earth's climate. We present a detailed overview of existing SSI measurements and provide thorough comparison of models available to date. SSI changes influence the Earth's atmosphere, both directly, through changes in shortwave (SW) heating and therefore, temperature and ozone distributions in the stratosphere, and indirectly, through dynamical feedbacks. We investigate these direct and indirect effects using several state-of-the art CCM simulations forced with measured and modeled SSI changes. A unique asset of this study is the use of a common comprehensive approach for an issue that is usually addressed separately by different communities. Omissis. Finally, we discuss the reliability of the available data and we propose additional coordinated work, first to build composite SSI datasets out of scattered observations and to refine current SSI models, and second, to run coordinated CCM experiments., Comment: 34 pages, 12 figures, accepted for publication in ACP

Published
2013
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4. Trends and natural variability in ozone and temperature profiles as depicted in Chemistry-Climate Models and Observations

Author

Tourpali, K.

Abstract

Stratospheric ozone levels, temperature trends and their evolution in time have been the subject of global concern and scientific research already since the mid 1970’s. The evolution of changes and trends in the vertical distribution of ozone and temperature as depicted in Chemistry-Climate Models simulations (CCMI) is examined. The solar signature in stratospheric variability is assessed, as well as the contribution of other natural variability forcings (such as ENSO, QBO and volcanic activity). Ozone and temperature trends are calculated for the periods before and after the year 2000 (pre-2000 and post-2000). Results are compared to trends derived from earlier model studies as well as to ozone trends from satellite records updated in the LOTUS SPARC project, over the same periods and latitude belts characteristic to the ozone variability, by applying the same statistical methods in accordance with the regression analysis and tools presented in the LOTUS Project., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Published
2023
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13. Solar Signals in CMIP-5 Simulations: The Stratospheric Pathway

Author

Mitchell, D.M, Misios, S, Gray, L. J, Tourpali, K, Matthes, K, Hood, L, Schmidt, H, Chiodo, G, Thieblemont, R, Rozanov, E, Shindell, D, and Krivolutsky, A

Subjects
Meteorology And Climatology
Abstract

The 11 year solar-cycle component of climate variability is assessed in historical simulations of models taken from the Coupled Model Intercomparison Project, phase 5 (CMIP-5). Multiple linear regression is applied to estimate the zonal temperature, wind and annular mode responses to a typical solar cycle, with a focus on both the stratosphere and the stratospheric influence on the surface over the period approximately 1850-2005. The analysis is performed on all CMIP-5 models but focuses on the 13 CMIP-5 models that resolve the stratosphere (high-top models) and compares the simulated solar cycle signature with reanalysis data. The 11 year solar cycle component of climate variability is found to be weaker in terms of magnitude and latitudinal gradient around the stratopause in the models than in the reanalysis. The peak in temperature in the lower equatorial stratosphere (approximately 70 hPa) reported in some studies is found in the models to depend on the length of the analysis period, with the last 30 years yielding the strongest response. A modification of the Polar Jet Oscillation (PJO) in response to the 11 year solar cycle is not robust across all models, but is more apparent in models with high spectral resolution in the short-wave region. The PJO evolution is slower in these models, leading to a stronger response during February, whereas observations indicate it to be weaker. In early winter, the magnitude of the modeled response is more consistent with observations when only data from 1979-2005 are considered. The observed North Pacific high-pressure surface response during the solar maximum is only simulated in some models, for which there are no distinguishing model characteristics. The lagged North Atlantic surface response is reproduced in both high- and low-top models, but is more prevalent in the former. In both cases, the magnitude of the response is generally lower than in observations.

Published
2015
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16. Chapter 5: Time series and trend results

Author

Hassler, B., Damadeo, R., Chang, K-L., Sofieva, V. F., Tourpali, K., Frith, S. M., Ball, W. T., Degenstein, D. A., Godin-Beekmann, S., Hubert, D., Maillard-Barras, E., Misios, S., Petropavlovskikh, I., Roth, C. Z., Steinbrecht, W., Vigouroux, C., von Clarmann, T., Zawada, D. J., Zerefos, C. S., Alsing, J., Balis, D., Coldewey-Egbers, M., Eleftheratos, K., Gruzdev, A., Kapsomenakis, J., Laeng, A., Laine, M., Taylor, Michael, Weber, M., Wild, J. D., Petropavlovskikh, I., Godin-Beekmann, S., Hubert, D., Damadeo, R., Hassler, B., and Sofieva, V.

Abstract

The ultimate goal of LOTUS is to improve confidence in calculated ozone trend values via an improved understanding of the uncertainties. Chapter 3 highlighted many of the challenges facing analyses of long-term ozone time series, and despite the fact that many of those challenges still need to be addressed, it is worthwhile to assess the trend results from this work in such a way as to be able to place those in the context of previous work. This chapter highlights the results of taking the "LOTUS regression" model from Chapter 4 and applying it to the different data sets (i.e., satellite, ground, and model) at different resolutions comparable to those in previous ozone assessments and comprehensive studies (e.g., WMO, 2014; Harris et al., 2015; Steinbrecht et al., 2017). The individual satellite-based trend results are then combined to obtain a single mean ozone trend profile with respective uncertainty estimates. This important yet challenging final step in the assessment has been the cause of debate in the community in recent years. Different methods for combining the individual trend results are discussed and explained, and the final trend profile estimates are analysed for significance.

Published
2019

17. Chapter 4: The LOTUS regression model

Author

Damadeo, R., Hassler, B., Zawada, D. J., Frith, S. M., Ball, W. T., Chang, K-L., Degenstein, D. A., Hubert, D., Misios, S., Petropavlovskikh, I., Roth, C. Z., Sofieva, V. F., Steinbrecht, W., Tourpali, K., Zerefos, C. S., Alsing, J., Balis, D., Coldewey-Egbers, M., Eleftheratos, K., Godin-Beekmann, S., Gruzdev, A., Kapsomenakis, J., Laeng, A., Laine, M., Maillard-Barras, E., Taylor, Michael, von Clarmann, T., Weber, M., Wild, J. D., Petropavlovskikh, I., Godin-Beekmann, S., Hubert, D., Damadeo, R., Hassler, B., and Sofieva, V.

Abstract

One of the primary motivations of the LOTUS effort is to attempt to reconcile the discrepancies in ozone trend results from the wealth of literature on the subject. Doing so requires investigating the various methodologies employed to derive long-term trends in ozone as well as to examine the large array of possible variables that feed into those methodologies and analyse their impacts on potential trend results. Given the limited amount of time, the LOTUS group focused on the most common methodology of multiple linear regression and performed a number of sensitivity tests with the goal of trying to establish best practices and come to a consensus on a single regression model to use for this study. This chapter discusses the details and results of the sensitivity tests before describing the components of the final single model that was chosen and the reasons for that choice.

Published
2019

18. 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

19. State of the climate in 2018

Author

Ades, M., Adler, R., Aldeco, L.S., Alejandra, G., Alfaro, E.J., Aliaga-Nestares, V., Allan, R.P., Allan, R., Alves, L.M., Amador, J.A., Andersen, J.K., Anderson, J., Arndt, D.S., Arosio, C., Arrigo, K., Azorin-Molina, C., Bardin, M.Y., Barichivich, J., Barreira, S., Baxter, S., Beck, H.E., Becker, A., Bell, G.D., Bellouin, N., Belmont, M., Benedetti, A., Benedict, I., Bernhard, G.H., Berrisford, P., Berry, D.I., Bettio, L., Bhatt, U.S., Biskaborn, B.K., Bissolli, P., Bjella, K.L., Bjerke, J.K., Blake, E.S., Blenkinsop, S., Blunden, J., Bock, O., Bosilovich, M.G., Boucher, O., Box, J.E., Boyer, T., Braathen, G., Bringas, F.G., Bromwich, D.H., Brown, A., Brown, R., Brown, T.J., Buehler, S.A., Cáceres, L., Calderón, B., Camargo, S.J., Campbell, J.D., Campos Diaz, D.A., Cappelen, J., Carrea, L., Carrier, S.B., Carter, B.R., Castro, A.Y., Cetinic, I., Chambers, D.P., Chen, L., Cheng, L., Cheng, V.Y.S., Christiansen, H.H., Christy, J.R., Chung, E.-S., Claus, F., Clem, K.R., Coelho, C.A.S., Coldewey-Egbers, M., Colwell, S., Cooper, O.R., Cosca, C., Covey, C., Coy, L., Dávila, C.P., Davis, S.M., de Eyto, E., de Jeu, R.A.M., De Laat, J., Decharme, B., Degasperi, C.L., Degenstein, D., Demircan, M., Derksen, C., Dhurmea, K.R., Di Girolamo, L., Diamond, H.J., Diaz, E., Diniz, F.A., Dlugokencky, E.J., Dohan, K., Dokulil, M.T., Dolman, A.J., Domingues, C.M., Domingues, R., Donat, M.G., Dorigo, W.A., Drozdov, D.S., Druckenmiller, M.L., Dunn, R.J.H., Durre, I., Dutton, G.S., Elkharrim, M., Elkins, J.W., Epstein, H.E., Espinoza, J.C., Famiglietti, J.S., Farrell, S.L., Fausto, R.S., Feely, R.A., Feng, Z., Fenimore, C., Fettweis, X., Fioletov, V.E., Flemming, J., Fogt, R.L., Forbes, B.C., Foster, M.J., Francis, S.D., Franz, B.A., Frey, R.A., Frith, S.M., Froidevaux, L., Ganter, C., Garforth, J., Gerland, S., Gilson, J., Gleason, K., Gobron, N., Goetz, S., Goldenberg, S.B., Goni, G., Gray, A., Groo, J.-U., Gruber, A., Gu, G., Guard, C.C.P., Gupta, S.K., Gutiérrez, D., Haas, Christian, Hagos, S., Hahn, S., Haimberger, L., Hall, B.D., Halpert, M.S., Hamlington, B.D., Hanna, E., Hanssen-Bauer, I., Harris, I., Hazeleger, W., He, Q., Heidinger, A.K., Heim, Jr., Hemming, D.L., Hendricks, Stefan, Hernández, R., Hersbach, H.E., Hidalgo, H.G., Ho, S.-P.B., Holmes, R.M., Hu, C., Huang, B., Hubbard, K., Hubert, D., Hurst, D.F., Ialongo, I., Ijampy, J.A., Inness, A., Isaac, V., Isaksen, K., Ishii, M., Jeffries, M.O., Jevrejeva, S., Jia, G., Jiménez, C., Jin, X., John, V., Johnsen, B., Johnson, G.C., Johnson, K.S., Johnson, B., Jones, P.D., Jumaux, G., Kabidi, K., Kaiser, J.W., Karaköylü, E.M., Karlsen, S.-R., Karnauskas, M., Kato, S., Kazemi, A.F., Kelble, C., Keller, L.M., Kennedy, J., Kholodov, A.L., Khoshkam, M., Kidd, R., Killick, R., Kim, H., Kim, S.-J., King, A.D., King, B.A., Kipling, Z., Klotzbach, P.J., Knaff, J.A., Korhonen, J., Korshunova, N.N., Kramarova, N.A., Kratz, D.P., Kruger, A., Kruk, M.C., Krumpen, Thomas, Labbé, L., Ladd, C., Lakatos, M., Lakkala, K., Lander, M.A., Landschützer, P., Landsea, C.W., Lareau, N.P., Lavado-Casimiro, W., Lazzara, M.A., Lee, T.C., Leuliette, E., L�heureux, M., Li, B., Li, T., Lieser, J.L., Lim, J.-Y., Lin, I.-I., Liu, H., Locarnini, R., Loeb, N.G., Long, C.S., López, L.A., Lorrey, A.M., Loyola, D., Lumpkin, R., Luo, J.-J., Luojus, K., Lyman, J.M., Malkova, G.V., Manney, G.L., Marchenko, S.S., Marengo, J.A., Marin, D., Marquardt Collow, A.B., Marra, J.J., Marszelewski, W., Martens, B., Martínez-Güingla, R., Massom, R.A., May, L., Mayer, M., Mazloff, M., McBride, C., McCabe, M., McClelland, J.W., McEvoy, D.J., McGree, S., McVicar, T.R., Mears, C.A., Meier, W., Meijers, A., Mekonnen, A., Mengistu Tsidu, G., Menzel, W.P., Merchant, C.J., Meredith, M.P., Merrifield, M.A., Miller, B., Miralles, D.G., Misevicius, N., Mitchum, G.T., Mochizuki, Y., Monselesan, D., Montzka, S.A., Mora, N., Morice, C., Mosquera-Vásquez, K., Mostafa, A.E., Mote, T., Mudryk, L., Mühle, J., Mullan, A.B., Müller, R., Myneni, R., Nash, E.R., Nauslar, N.J., Nerem, R.S., Newman, P.A., Nicolas, J.P., Nieto, J.J., Noetzli, J., Osborn, T.J., Osborne, E., Overland, J., Oyunjargal, L., Park, T., Pasch, R.J., Pascual Ramírez, R., Pastor Saavedra, M.A., Paterson, A.M., Pearce, P.R., Pelto, M.S., Perovich, D., Petropavlovskikh, I., Pezza, A.B., Phillips, C., Phillips, D., Phoenix, G., Pinty, B., Pitts, M., Po-Chedley, S., Polashenski, C., Preimesberger, W., Purkey, S.G., Quispe, N., Rajeevan, M., Rakotoarimalala, C.L., Ramos, A.M., Ramos, I., Randel, W., Raynolds, M.K., Reagan, J., Reid, P., Reimer, C., Rémy, S., Revadekar, J.V., Richardson, A.D., Richter-Menge, J., Ricker, Robert, Ripaldi, A., Robinson, D.A., Rodell, M., Rodriguez Camino, E., Romanovsky, V.E., Ronchail, J., Rosenlof, K.H., Rösner, B., Roth, C., Rozanov, A., Rusak, J.A., Rustemeier, E., Rutishäuser, T., Sallée, J.-B., Sánchez-Lugo, A., Santee, M.L., Sawaengphokhai, P., Sayouri, A., Scambos, T.A., Scanlon, T., Scardilli, A.S., Schenzinger, V., Schladow, S.G., Schmid, C., Schmid, M., Schoeneich, P., Schreck, III, Selkirk, H.B., Sensoy, S., Shi, L., Shiklomanov, A.I., Shiklomanov, N.I., Shimpo, A., Shuman, C.A., Siegel, D.A., Sima, F., Simmons, A.J., Smeets, C.J.P.P., Smith, A., Smith, S.L., Soden, B., Sofieva, V., Sparks, T.H., Spence, J., Spencer, R.G.M., Spillane, S., Srivastava, A.K., Stabeno, P.J., Stackhouse, Jr., Stammerjohn, S., Stanitski, D.M., Steinbrecht, W., Stella, J.L., Stengel, M., Stephenson, T.S., Strahan, S.E., Streeter, C., Streletskiy, D.A., Sun-Mack, S., Suslova, A., Sutton, A.J., Swart, S., Sweet, W., Takahashi, K.S., Tank, S.E., Taylor, M.A., Tedesco, M., Thackeray, S.J., Thompson, P.R., Timbal, B., Timmermans, M.-L., Tobin, S., Tømmervik, H., Tourpali, K., Trachte, K., Tretiakov, M., Trewin, B.C., Triñanes, J.A., Trotman, A.R., Tschudi, M., Tye, M.R., van As, D., van de Wal, R.S.W., van der A, R.J., van der Schalie, R., van der Schrier, G., van der Werf, G.R., van Heerwaarden, C., Van Meerbeeck, C.J., Verburg, P., Vieira, G., Vincent, L.A., Vömel, H., Vose, R.S., Walker, D.A., Walsh, J.E., Wang, B., Wang, H., Wang, L., Wang, M., Wang, R., Wang, S.-H., Wanninkhof, R., Watanabe, S., Weber, M., Webster, M., Weerts, A., Weller, R.A., Westberry, T.K., Weyhenmeyer, G.A., Widlansky, M.J., Wijffels, S.E., Wilber, A.C., Wild, J.D., Willett, K.M., Wong, T., Wood, E.F., Woolway, R.I., Xue, Y., Yin, X., Yu, L., Zambrano, E., Zeyaeyan, S., Zhang, H.-M., Zhang, P., Zhao, G., Zhao, L., Zhou, X., Zhu, Z., Ziemke, J.R., Ziese, M., Andersen, A., Griffin, J., Hammer, G., Love-Brotak, S.E., Misch, D.J., Riddle, D.B., Veasey, S.W., Ades, M., Adler, R., Aldeco, L.S., Alejandra, G., Alfaro, E.J., Aliaga-Nestares, V., Allan, R.P., Allan, R., Alves, L.M., Amador, J.A., Andersen, J.K., Anderson, J., Arndt, D.S., Arosio, C., Arrigo, K., Azorin-Molina, C., Bardin, M.Y., Barichivich, J., Barreira, S., Baxter, S., Beck, H.E., Becker, A., Bell, G.D., Bellouin, N., Belmont, M., Benedetti, A., Benedict, I., Bernhard, G.H., Berrisford, P., Berry, D.I., Bettio, L., Bhatt, U.S., Biskaborn, B.K., Bissolli, P., Bjella, K.L., Bjerke, J.K., Blake, E.S., Blenkinsop, S., Blunden, J., Bock, O., Bosilovich, M.G., Boucher, O., Box, J.E., Boyer, T., Braathen, G., Bringas, F.G., Bromwich, D.H., Brown, A., Brown, R., Brown, T.J., Buehler, S.A., Cáceres, L., Calderón, B., Camargo, S.J., Campbell, J.D., Campos Diaz, D.A., Cappelen, J., Carrea, L., Carrier, S.B., Carter, B.R., Castro, A.Y., Cetinic, I., Chambers, D.P., Chen, L., Cheng, L., Cheng, V.Y.S., Christiansen, H.H., Christy, J.R., Chung, E.-S., Claus, F., Clem, K.R., Coelho, C.A.S., Coldewey-Egbers, M., Colwell, S., Cooper, O.R., Cosca, C., Covey, C., Coy, L., Dávila, C.P., Davis, S.M., de Eyto, E., de Jeu, R.A.M., De Laat, J., Decharme, B., Degasperi, C.L., Degenstein, D., Demircan, M., Derksen, C., Dhurmea, K.R., Di Girolamo, L., Diamond, H.J., Diaz, E., Diniz, F.A., Dlugokencky, E.J., Dohan, K., Dokulil, M.T., Dolman, A.J., Domingues, C.M., Domingues, R., Donat, M.G., Dorigo, W.A., Drozdov, D.S., Druckenmiller, M.L., Dunn, R.J.H., Durre, I., Dutton, G.S., Elkharrim, M., Elkins, J.W., Epstein, H.E., Espinoza, J.C., Famiglietti, J.S., Farrell, S.L., Fausto, R.S., Feely, R.A., Feng, Z., Fenimore, C., Fettweis, X., Fioletov, V.E., Flemming, J., Fogt, R.L., Forbes, B.C., Foster, M.J., Francis, S.D., Franz, B.A., Frey, R.A., Frith, S.M., Froidevaux, L., Ganter, C., Garforth, J., Gerland, S., Gilson, J., Gleason, K., Gobron, N., Goetz, S., Goldenberg, S.B., Goni, G., Gray, A., Groo, J.-U., Gruber, A., Gu, G., Guard, C.C.P., Gupta, S.K., Gutiérrez, D., Haas, Christian, Hagos, S., Hahn, S., Haimberger, L., Hall, B.D., Halpert, M.S., Hamlington, B.D., Hanna, E., Hanssen-Bauer, I., Harris, I., Hazeleger, W., He, Q., Heidinger, A.K., Heim, Jr., Hemming, D.L., Hendricks, Stefan, Hernández, R., Hersbach, H.E., Hidalgo, H.G., Ho, S.-P.B., Holmes, R.M., Hu, C., Huang, B., Hubbard, K., Hubert, D., Hurst, D.F., Ialongo, I., Ijampy, J.A., Inness, A., Isaac, V., Isaksen, K., Ishii, M., Jeffries, M.O., Jevrejeva, S., Jia, G., Jiménez, C., Jin, X., John, V., Johnsen, B., Johnson, G.C., Johnson, K.S., Johnson, B., Jones, P.D., Jumaux, G., Kabidi, K., Kaiser, J.W., Karaköylü, E.M., Karlsen, S.-R., Karnauskas, M., Kato, S., Kazemi, A.F., Kelble, C., Keller, L.M., Kennedy, J., Kholodov, A.L., Khoshkam, M., Kidd, R., Killick, R., Kim, H., Kim, S.-J., King, A.D., King, B.A., Kipling, Z., Klotzbach, P.J., Knaff, J.A., Korhonen, J., Korshunova, N.N., Kramarova, N.A., Kratz, D.P., Kruger, A., Kruk, M.C., Krumpen, Thomas, Labbé, L., Ladd, C., Lakatos, M., Lakkala, K., Lander, M.A., Landschützer, P., Landsea, C.W., Lareau, N.P., Lavado-Casimiro, W., Lazzara, M.A., Lee, T.C., Leuliette, E., L�heureux, M., Li, B., Li, T., Lieser, J.L., Lim, J.-Y., Lin, I.-I., Liu, H., Locarnini, R., Loeb, N.G., Long, C.S., López, L.A., Lorrey, A.M., Loyola, D., Lumpkin, R., Luo, J.-J., Luojus, K., Lyman, J.M., Malkova, G.V., Manney, G.L., Marchenko, S.S., Marengo, J.A., Marin, D., Marquardt Collow, A.B., Marra, J.J., Marszelewski, W., Martens, B., Martínez-Güingla, R., Massom, R.A., May, L., Mayer, M., Mazloff, M., McBride, C., McCabe, M., McClelland, J.W., McEvoy, D.J., McGree, S., McVicar, T.R., Mears, C.A., Meier, W., Meijers, A., Mekonnen, A., Mengistu Tsidu, G., Menzel, W.P., Merchant, C.J., Meredith, M.P., Merrifield, M.A., Miller, B., Miralles, D.G., Misevicius, N., Mitchum, G.T., Mochizuki, Y., Monselesan, D., Montzka, S.A., Mora, N., Morice, C., Mosquera-Vásquez, K., Mostafa, A.E., Mote, T., Mudryk, L., Mühle, J., Mullan, A.B., Müller, R., Myneni, R., Nash, E.R., Nauslar, N.J., Nerem, R.S., Newman, P.A., Nicolas, J.P., Nieto, J.J., Noetzli, J., Osborn, T.J., Osborne, E., Overland, J., Oyunjargal, L., Park, T., Pasch, R.J., Pascual Ramírez, R., Pastor Saavedra, M.A., Paterson, A.M., Pearce, P.R., Pelto, M.S., Perovich, D., Petropavlovskikh, I., Pezza, A.B., Phillips, C., Phillips, D., Phoenix, G., Pinty, B., Pitts, M., Po-Chedley, S., Polashenski, C., Preimesberger, W., Purkey, S.G., Quispe, N., Rajeevan, M., Rakotoarimalala, C.L., Ramos, A.M., Ramos, I., Randel, W., Raynolds, M.K., Reagan, J., Reid, P., Reimer, C., Rémy, S., Revadekar, J.V., Richardson, A.D., Richter-Menge, J., Ricker, Robert, Ripaldi, A., Robinson, D.A., Rodell, M., Rodriguez Camino, E., Romanovsky, V.E., Ronchail, J., Rosenlof, K.H., Rösner, B., Roth, C., Rozanov, A., Rusak, J.A., Rustemeier, E., Rutishäuser, T., Sallée, J.-B., Sánchez-Lugo, A., Santee, M.L., Sawaengphokhai, P., Sayouri, A., Scambos, T.A., Scanlon, T., Scardilli, A.S., Schenzinger, V., Schladow, S.G., Schmid, C., Schmid, M., Schoeneich, P., Schreck, III, Selkirk, H.B., Sensoy, S., Shi, L., Shiklomanov, A.I., Shiklomanov, N.I., Shimpo, A., Shuman, C.A., Siegel, D.A., Sima, F., Simmons, A.J., Smeets, C.J.P.P., Smith, A., Smith, S.L., Soden, B., Sofieva, V., Sparks, T.H., Spence, J., Spencer, R.G.M., Spillane, S., Srivastava, A.K., Stabeno, P.J., Stackhouse, Jr., Stammerjohn, S., Stanitski, D.M., Steinbrecht, W., Stella, J.L., Stengel, M., Stephenson, T.S., Strahan, S.E., Streeter, C., Streletskiy, D.A., Sun-Mack, S., Suslova, A., Sutton, A.J., Swart, S., Sweet, W., Takahashi, K.S., Tank, S.E., Taylor, M.A., Tedesco, M., Thackeray, S.J., Thompson, P.R., Timbal, B., Timmermans, M.-L., Tobin, S., Tømmervik, H., Tourpali, K., Trachte, K., Tretiakov, M., Trewin, B.C., Triñanes, J.A., Trotman, A.R., Tschudi, M., Tye, M.R., van As, D., van de Wal, R.S.W., van der A, R.J., van der Schalie, R., van der Schrier, G., van der Werf, G.R., van Heerwaarden, C., Van Meerbeeck, C.J., Verburg, P., Vieira, G., Vincent, L.A., Vömel, H., Vose, R.S., Walker, D.A., Walsh, J.E., Wang, B., Wang, H., Wang, L., Wang, M., Wang, R., Wang, S.-H., Wanninkhof, R., Watanabe, S., Weber, M., Webster, M., Weerts, A., Weller, R.A., Westberry, T.K., Weyhenmeyer, G.A., Widlansky, M.J., Wijffels, S.E., Wilber, A.C., Wild, J.D., Willett, K.M., Wong, T., Wood, E.F., Woolway, R.I., Xue, Y., Yin, X., Yu, L., Zambrano, E., Zeyaeyan, S., Zhang, H.-M., Zhang, P., Zhao, G., Zhao, L., Zhou, X., Zhu, Z., Ziemke, J.R., Ziese, M., Andersen, A., Griffin, J., Hammer, G., Love-Brotak, S.E., Misch, D.J., Riddle, D.B., and Veasey, S.W.

Published
2019

20. Solar signals in CMIP-5 simulations: effects of atmosphere-ocean couplingSurface Solar Signals in CMIP-5

Author

Misios S., Mitchell D. M., Gray L. J., Tourpali K., Matthes K., Hood L., Schmidt H., Chiodo G., Thiéblemont R., Rozanov E., and Krivolutsky A.

Subjects
Physics::Space Physics, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Physics::Atmospheric and Oceanic Physics, Physics::Geophysics
Abstract

The surface response to the 11 year solar cycle is assessed in ensemble simulations of the twentieth century climate performed in the framework of the fifth phase of the Coupled Model Inter Comparison Project (CMIP5). A lead/lag multiple linear regression analysis identifies a multi model mean (MMM) global mean surface warming of about 0.07 K lagging the solar cycle by 1 2 years on average. The anomalous warming penetrates to approximately the first 80 100 m depth in the ocean. Solar signals in the troposphere show a similar time lag of 1 2 years and the strongest MMM warming is simulated in the Tropics above 300 hPa. At the surface the MMM response in a subset of models that show statistically significant global mean warming (CMIP5 SIG95) is characterized by an anomalous warming in the west equatorial Pacific Ocean and the Arctic at 1 2 years after solar maximum. The Arctic warming is twice as strong as the global mean response and appears in the winter months only. The surface warming in the equatorial Pacific Ocean is related to dynamical/thermodynamical processes. Different increase rates of global mean precipitation and atmospheric water vapour in response to a warmer surface lead to a weaker Walker circulation and anomalous westerly winds over the equatorial Pacific in the years following the solar maximum. Owing to atmosphere ocean coupling the anomalous westerly winds cool the subsurface and warm the surface in the western equatorial Pacific by approximate to 0.14 K. The CMIP5 SIG95 MMM surface warming in the equatorial Pacific and Arctic is weak but qualitatively similar compared with solar signals in the HadCRUT4 dataset.

Published
2016
Full Text
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21. Stratospheric Ozone

Author

Weber, Mark, Steinbrecht, Wolfgang, van der A, Ronald, Frith, Stacey, Anderson, John, Coldewey-Egbers, Melanie, Davis, Sean M., Degenstein, Doug, Fioletov, Vitali E., Froidevaux, Lucien, Hubert, Daan, de Laat, Jos, Long, Craig, Loyola, Diego, Sofieva, Viktoria, Tourpali, K., Roth, Chris, Wang, Ray, Wild, Jeanette, Blunden, J, Arndt, D, and Hartfield, G

Subjects
stratospheric ozone, Atmosphärenprozessoren
Published
2018

22. Representativeness of single lidar stations for zonally averaged ozone profiles, their trends and attribution to proxies

Author

Zerefos, C. Kapsomenakis, J. Eleftheratos, K. Tourpali, K. Petropavlovskikh, I. Hubert, D. Godin-Beekmann, S. Steinbrecht, W. Frith, S. Sofieva, V. Hassler, B.

Abstract

This paper is focusing on the representativeness of single lidar stations for zonally averaged ozone profile variations over the middle and upper stratosphere. From the lower to the upper stratosphere, ozone profiles from single or grouped lidar stations correlate well with zonal means calculated from the Solar Backscatter Ultraviolet Radiometer (SBUV) satellite overpasses. The best representativeness with significant correlation coefficients is found within ±15° of latitude circles north or south of any lidar station. This paper also includes a multivariate linear regression (MLR) analysis on the relative importance of proxy time series for explaining variations in the vertical ozone profiles. Studied proxies represent variability due to influences outside of the earth system (solar cycle) and within the earth system, i.e. dynamic processes (the Quasi Biennial Oscillation, QBO; the Arctic Oscillation, AO; the Antarctic Oscillation, AAO; the El Niño Southern Oscillation, ENSO), those due to volcanic aerosol (aerosol optical depth, AOD), tropopause height changes (including global warming) and those influences due to anthropogenic contributions to atmospheric chemistry (equivalent effective stratospheric chlorine, EESC). Ozone trends are estimated, with and without removal of proxies, from the total available 1980 to 2015 SBUV record. Except for the chemistry related proxy (EESC) and its orthogonal function, the removal of the other proxies does not alter the significance of the estimated long-term trends. At heights above 15 hPa an inflection point between 1997 and 1999 marks the end of significant negative ozone trends, followed by a recent period between 1998 and 2015 with positive ozone trends. At heights between 15 and 40 hPa the pre-1998 negative ozone trends tend to become less significant as we move towards 2015, below which the lower stratosphere ozone decline continues in agreement with findings of recent literature. © 2018 Author(s).

Published
2018

25. Solar forcing for CMIP6 (v3.2)

Author

Matthes, K, Funke, B, Andersson, ME, Barnard, L, Beer, J, Charbonneau, P, Clilverd, MA, De Wit, T, Haberreiter, M, Hendry, A, Jackman, CH, Kretzschmar, M, Kruschke, T, Kunze, M, Langematz, U, Marsh, DR, Maycock, AC, Misios, S, Rodger, CJ, Scaife, AA, Seppälä, A, Shangguan, M, Sinnhuber, M, Tourpali, K, Usoskin, I, Van De Kamp, M, Verronen, PT, Versick, S, Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Instituto de Astrofísica de Andalucı'a-CSIC, Finnish Meteorological Institute (FMI), University of Reading (UOR), Swiss Federal Insitute of Aquatic Science and Technology [Dübendorf] (EAWAG), Université de Montréal (UdeM), British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center (PMOD/WRC), University of Otago [Dunedin, Nouvelle-Zélande], NASA Goddard Space Flight Center (GSFC), Institut für Meteorologie [Berlin], Freie Universität Berlin, National Center for Atmospheric Research [Boulder] (NCAR), University of Leeds, Aristotle University of Thessaloniki, Department of Physics [Dunedin], Met Office Hadley Centre for Climate Change (MOHC), United Kingdom Met Office [Exeter], Karlsruhe Institute of Technology (KIT), Laboratory of Atmospheric Physics [Thessaloniki], University of Oulu, Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES)

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Earth sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], ddc:550
Abstract

This paper describes the recommended solar forcing dataset for CMIP6 and highlights changes with respect to CMIP5. The solar forcing is provided for radiative properties, namely total solar irradiance (TSI), solar spectral irradiance (SSI), and the F10.7 index as well as particle forcing, including geomagnetic indices Ap and Kp, and ionization rates to account for effects of solar protons, electrons, and galactic cosmic rays. This is the first time that a recommendation for solar-driven particle forcing has been provided for a CMIP exercise. The solar forcing datasets are provided at daily and monthly resolution separately for the CMIP6 preindustrial control, historical (1850–2014), and future (2015–2300) simulations. For the preindustrial control simulation, both constant and time-varying solar forcing components are provided, with the latter including variability on 11-year and shorter timescales but no long-term changes. For the future, we provide a realistic scenario of what solar behavior could be, as well as an additional extreme Maunder-minimum-like sensitivity scenario. This paper describes the forcing datasets and also provides detailed recommendations as to their implementation in current climate models.For the historical simulations, the TSI and SSI time series are defined as the average of two solar irradiance models that are adapted to CMIP6 needs: an empirical one (NRLTSI2–NRLSSI2) and a semi-empirical one (SATIRE). A new and lower TSI value is recommended: the contemporary solar-cycle average is now 1361.0 W m−2. The slight negative trend in TSI over the three most recent solar cycles in the CMIP6 dataset leads to only a small global radiative forcing of −0.04 W m−2. In the 200–400 nm wavelength range, which is important for ozone photochemistry, the CMIP6 solar forcing dataset shows a larger solar-cycle variability contribution to TSI than in CMIP5 (50 % compared to 35 %).We compare the climatic effects of the CMIP6 solar forcing dataset to its CMIP5 predecessor by using time-slice experiments of two chemistry–climate models and a reference radiative transfer model. The differences in the long-term mean SSI in the CMIP6 dataset, compared to CMIP5, impact on climatological stratospheric conditions (lower shortwave heating rates of −0.35 K day−1 at the stratopause), cooler stratospheric temperatures (−1.5 K in the upper stratosphere), lower ozone abundances in the lower stratosphere (−3 %), and higher ozone abundances (+1.5 % in the upper stratosphere and lower mesosphere). Between the maximum and minimum phases of the 11-year solar cycle, there is an increase in shortwave heating rates (+0.2 K day−1 at the stratopause), temperatures ( ∼ 1 K at the stratopause), and ozone (+2.5 % in the upper stratosphere) in the tropical upper stratosphere using the CMIP6 forcing dataset. This solar-cycle response is slightly larger, but not statistically significantly different from that for the CMIP5 forcing dataset.CMIP6 models with a well-resolved shortwave radiation scheme are encouraged to prescribe SSI changes and include solar-induced stratospheric ozone variations, in order to better represent solar climate variability compared to models that only prescribe TSI and/or exclude the solar-ozone response. We show that monthly-mean solar-induced ozone variations are implicitly included in the SPARC/CCMI CMIP6 Ozone Database for historical simulations, which is derived from transient chemistry–climate model simulations and has been developed for climate models that do not calculate ozone interactively. CMIP6 models without chemistry that perform a preindustrial control simulation with time-varying solar forcing will need to use a modified version of the SPARC/CCMI Ozone Database that includes solar variability. CMIP6 models with interactive chemistry are also encouraged to use the particle forcing datasets, which will allow the potential long-term effects of particles to be addressed for the first time. The consideration of particle forcing has been shown to significantly improve the representation of reactive nitrogen and ozone variability in the polar middle atmosphere, eventually resulting in further improvements in the representation of solar climate variability in global models.

Published
2017

26. Solar forcing for CMIP6 (v3.2)

Author

Matthes, K. (Katja), Funke, B. (Bernd), Andersson, M. E. (Monika E.), Barnard, L. (Luke), Beer, J. (Jürg), Charbonneau, P. (Paul), Clilverd, M. A. (Mark A.), Dudok de Wit, T. (Thierry), Haberreiter, M. (Margit), Hendry, A. (Aaron), Jackman, C. H. (Charles H.), Kretzschmar, M. (Matthieu), Kruschke, T. (Tim), Kunze, M. (Markus), Langematz, U. (Ulrike), Marsh, D. R. (Daniel R.), Maycock, A. C. (Amanda C.), Misios, S. (Stergios), Rodger, C. J. (Craig J.), Scaife, A. A. (Adam A.), Seppälä, A. (Annika), Shangguan, M. (Ming), Sinnhuber, M. (Miriam), Tourpali, K. (Kleareti), Usoskin, I. (Ilya), van de Kamp, M. (Max), Verronen, P. T. (Pekka T.), Versick, S. (Stefan), Matthes, K. (Katja), Funke, B. (Bernd), Andersson, M. E. (Monika E.), Barnard, L. (Luke), Beer, J. (Jürg), Charbonneau, P. (Paul), Clilverd, M. A. (Mark A.), Dudok de Wit, T. (Thierry), Haberreiter, M. (Margit), Hendry, A. (Aaron), Jackman, C. H. (Charles H.), Kretzschmar, M. (Matthieu), Kruschke, T. (Tim), Kunze, M. (Markus), Langematz, U. (Ulrike), Marsh, D. R. (Daniel R.), Maycock, A. C. (Amanda C.), Misios, S. (Stergios), Rodger, C. J. (Craig J.), Scaife, A. A. (Adam A.), Seppälä, A. (Annika), Shangguan, M. (Ming), Sinnhuber, M. (Miriam), Tourpali, K. (Kleareti), Usoskin, I. (Ilya), van de Kamp, M. (Max), Verronen, P. T. (Pekka T.), and Versick, S. (Stefan)

Abstract

This paper describes the recommended solar forcing dataset for CMIP6 and highlights changes with respect to CMIP5. The solar forcing is provided for radiative properties, namely total solar irradiance (TSI), solar spectral irradiance (SSI), and the F10.7 index as well as particle forcing, including geomagnetic indices Ap and Kp, and ionization rates to account for effects of solar protons, electrons, and galactic cosmic rays. This is the first time that a recommendation for solar-driven particle forcing has been provided for a CMIP exercise. The solar forcing datasets are provided at daily and monthly resolution separately for the CMIP6 preindustrial control, historical (1850–2014), and future (2015–2300) simulations. For the preindustrial control simulation, both constant and time-varying solar forcing components are provided, with the latter including variability on 11-year and shorter timescales but no long-term changes. For the future, we provide a realistic scenario of what solar behavior could be, as well as an additional extreme Maunder-minimum-like sensitivity scenario. This paper describes the forcing datasets and also provides detailed recommendations as to their implementation in current climate models. For the historical simulations, the TSI and SSI time series are defined as the average of two solar irradiance models that are adapted to CMIP6 needs: an empirical one (NRLTSI2–NRLSSI2) and a semi-empirical one (SATIRE). A new and lower TSI value is recommended: the contemporary solar-cycle average is now 1361.0 W m⁻². The slight negative trend in TSI over the three most recent solar cycles in the CMIP6 dataset leads to only a small global radiative forcing of −0.04 W m⁻². In the 200–400 nm wavelength range, which is important for ozone photochemistry, the CMIP6 solar forcing dataset shows a larger solar-cycle variability contribution to TSI than in CMIP5 (50 % compared to 35 %). We compare the climatic effects of the CMIP6 solar forcing dataset t

Published
2017

27. Environmental effects of ozone depletion and its interactions with climate change: Progress report, 2016

Author

Andrady, A., Aucamp, P., Austin, A., Bais, A., Ballaré, C., Barnes, P., Bernhard, G., Björn, L., Bornman, Janet, Erickson, D., De Gruijl, F., Häder, D., Ilyas, M., Longstreth, J., Lucas, R., Madronich, S., McKenzie, R., Neale, R., Norval, M., Pandey, K., Paul, N., Redhwi, H., Robinson, S., Rose, K., Shao, M., Sinha, R., Solomon, K., Sulzberger, B., Takizawa, Y., Torikai, A., Tourpali, K., Williamson, C., Wilson, S., Wängberg, S., Worrest, R., Young, A., Zepp, R., Andrady, A., Aucamp, P., Austin, A., Bais, A., Ballaré, C., Barnes, P., Bernhard, G., Björn, L., Bornman, Janet, Erickson, D., De Gruijl, F., Häder, D., Ilyas, M., Longstreth, J., Lucas, R., Madronich, S., McKenzie, R., Neale, R., Norval, M., Pandey, K., Paul, N., Redhwi, H., Robinson, S., Rose, K., Shao, M., Sinha, R., Solomon, K., Sulzberger, B., Takizawa, Y., Torikai, A., Tourpali, K., Williamson, C., Wilson, S., Wängberg, S., Worrest, R., Young, A., and Zepp, R.

Abstract

© 2017 The Royal Society of Chemistry and Owner Societies. The Parties to the Montreal Protocol are informed by three Panels of experts. One of these is the Environmental Effects Assessment Panel (EEAP), which deals with two focal issues. The first focus is the effects of UV radiation on human health, animals, plants, biogeochemistry, air quality, and materials. The second focus is on interactions between UV radiation and global climate change and how these may affect humans and the environment. When considering the effects of climate change, it has become clear that processes resulting in changes in stratospheric ozone are more complex than previously believed. As a result of this, human health and environmental issues will be longer-lasting and more regionally variable. Like the other Panels, the EEAP produces a detailed report every four years; the most recent was published as a series of seven papers in 2015 (Photochem. Photobiol. Sci., 2015, 14, 1-184). In the years in between, the EEAP produces less detailed and shorter Progress Reports of the relevant scientific findings. The most recent of these was for 2015 (Photochem. Photobiol. Sci., 2016, 15, 141-147). The present Progress Report for 2016 assesses some of the highlights and new insights with regard to the interactive nature of the direct and indirect effects of UV radiation, atmospheric processes, and climate change. The more detailed Quadrennial Assessment will be made available in 2018.

Published
2017

28. Evaluation of simulated photolysis rates and their response to solar irradiance variability

Author

Sukhodolov, T, Rozanov, E, Ball, WT, Bais, A, Tourpali, K, Shapiro, AI, Telford, P, Smyshlyaev, S, Fomin, B, Sander, R, Bossay, S, Bekki, S, Marchand, M, Chipperfield, MP, Dhomse, S, Haigh, JD, Peter, T, and Schmutz, W

Subjects
CHEMICAL-MODELS, Science & Technology, STRATOSPHERIC OZONE, SPECTRAL IRRADIANCE, Physical Sciences, ROTATION CYCLE, ACCURATE SIMULATION, HEATING RATES, Meteorology & Atmospheric Sciences, CHEMISTRY-CLIMATE MODEL, DYNAMICAL RESPONSE, CIRCULATION MODEL, MIDDLE ATMOSPHERE
Abstract

The state of the stratospheric ozone layer and the temperature structure of the atmosphere are largely controlled by the solar spectral irradiance (SSI) through its influence on heating and photolysis rates. This study focuses on the uncertainties in the photolysis rate response to solar irradiance variability related to the choice of SSI data set and to the performance of the photolysis codes used in global chemistry-climate models. To estimate the impact of SSI uncertainties, we compared several photolysis rates calculated with the radiative transfer model libRadtran, using SSI calculated with two models and observed during the Solar Radiation and Climate Experiment (SORCE) satellite mission. The importance of the calculated differences in the photolysis rate response for ozone and temperature changes has been estimated using 1-D a radiative-convective-photochemical model. We demonstrate that the main photolysis reactions, responsible for the solar signal in the stratosphere, are highly sensitive to the spectral distribution of SSI variations. Accordingly, the ozone changes and related ozone-temperature feedback are shown to depend substantially on the SSI data set being used, which highlights the necessity of obtaining accurate SSI variations. To evaluate the performance of photolysis codes, we compared the results of eight, widely used, photolysis codes against two reference schemes. We show that, in most cases, absolute values of the photolysis rates and their response to applied SSI changes agree within 30%. However, larger errors may appear in specific atmospheric regions because of differences, for instance, in the treatment of Rayleigh scattering, quantum yields, or absorption cross sections.

Published
2016

29. Solar signals in CMIP‐5 simulations: the stratospheric pathway

Author

Mitchell D. M., Misios S., Gray L. J., Tourpali K., Matthes K., Hood L., Schmidt H., Chiodo G., Thieblemont R., Rozanov E., Shindell D., and Krivolutsky A.

Subjects
SolarMIP, Solar variability, Stratosphere, CMIP-5, Climate, Natural variability
Abstract

The 11 year solar‐cycle component of climate variability is assessed in historical simulations of models taken from the Coupled Model Intercomparison Project, phase 5 (CMIP‐5). Multiple linear regression is applied to estimate the zonal temperature, wind and annular mode responses to a typical solar cycle, with a focus on both the stratosphere and the stratospheric influence on the surface over the period ∼1850–2005. The analysis is performed on all CMIP‐5 models but focuses on the 13 CMIP‐5 models that resolve the stratosphere (high‐top models) and compares the simulated solar cycle signature with reanalysis data. The 11 year solar cycle component of climate variability is found to be weaker in terms of magnitude and latitudinal gradient around the stratopause in the models than in the reanalysis. The peak in temperature in the lower equatorial stratosphere (∼70 hPa) reported in some studies is found in the models to depend on the length of the analysis period, with the last 30 years yielding the strongest response. A modification of the Polar Jet Oscillation (PJO) in response to the 11 year solar cycle is not robust across all models, but is more apparent in models with high spectral resolution in the short‐wave region. The PJO evolution is slower in these models, leading to a stronger response during February, whereas observations indicate it to be weaker. In early winter, the magnitude of the modelled response is more consistent with observations when only data from 1979–2005 are considered. The observed North Pacific high‐pressure surface response during the solar maximum is only simulated in some models, for which there are no distinguishing model characteristics. The lagged North Atlantic surface response is reproduced in both high‐ and low‐top models, but is more prevalent in the former. In both cases, the magnitude of the response is generally lower than in observations. ISSN:0035-9009 ISSN:1477-870X

Published
2015

30. Ozone and spectroradiometric UV changes in the past 20 years over high latitudes

Author

Eleftheratos, K. Kazadzis, S. Zerefos, C.S. Tourpali, K. Meleti, C. Balis, D. Zyrichidou, I. Lakkala, K. Feister, U. Koskela, T. Heikkilä, A. Karhu, J.M.

Abstract

This study analyzes changes in solar ultraviolet (UV) irradiances at 305 and 325nm at selected sites located at high latitudes of both hemispheres. Site selection was restricted to the availability of the most complete UV spectroradiometric datasets of the past twenty years (1990-2011). The results show that over northern high latitudes, between 55° and 70°N, UV irradiances at 305nm decreased significantly by 3.9% per decade, whereas UV irradiance at 325nm remained stable with no significant long-term change. Over southern high latitudes (55°-70°S), UV irradiances did not show any significant long-term changes at either 305 or 325nm. Changes in solar UV irradiances are discussed in the context of long-term ozone and other atmospheric parameters affecting UV variability at ground level. © 2015 Canadian Meteorological and Oceanographic Society.

Published
2015

31. Solar signals in CMIP-5 Simulations: Effects of Atmosphere-ocean Coupling

Author

Misios, S., Mitchell, D. M., Gray, L. J., Tourpali, K., Matthes, Katja, Hood, L., Schmidt, H., Chiodo, G., Thiéblemont, R., Rozanov, E., Krivolutsky, A., Misios, S., Mitchell, D. M., Gray, L. J., Tourpali, K., Matthes, Katja, Hood, L., Schmidt, H., Chiodo, G., Thiéblemont, R., Rozanov, E., and Krivolutsky, A.

Abstract

The surface response to the 11-yr solar cycle is assessed in ensemble simulations of the 20th century climate performed in the framework of the 5th phase of the Coupled Model Inter-Comparison Project (CMIP5). A lead/lag multiple linear regression analysis identifies a multi-model mean (MMM) global mean surface warming of about 0.07 K lagging the solar cycle by one to two years on average. The anomalous warming penetrates to approximately the first 80–100 m depth in the ocean. Solar signals in the troposphere show a similar time lag of one to two years and the strongest MMM warming is simulated in the tropics above 300 hPa. At the surface, the MMM response in a subset of models that show statistically significant global mean warming (CMIP5-SIG95) is characterized by an anomalous warming in the west equatorial Pacific Ocean and the Arctic, at one to two years after solar maximum. The Arctic warming is twice as strong as the global mean response and appears in winter months only. The surface warming in the equatorial Pacific Ocean is related to dynamical/thermodynamical processes. Different increase rates of global mean precipitation and atmospheric water vapor in response to a warmer surface lead to a weaker Walker circulation and anomalous westerly winds over the equatorial Pacific in years following solar maximum. Owing to atmosphere–ocean coupling, the anomalous westerly winds cool the subsurface and warm the surface in the western equatorial Pacific by ∼ 0.14 K. The CMIP5-SIG95 MMM surface warming in the equatorial Pacific and Arctic is weak but qualitatively similar compared to solar signals in the HadCRUT4 dataset.

Published
2016
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32. Environmental effects of ozone depletion and its interactions with climate change: Progress report, 2015

Author

Andrady, A., Aucamp, P., Austin, A., Bais, A., Ballaré, C., Barnes, P., Bernhard, G., Björn, L., Bornman, Janet, Erickson, D., De Gruijl, F., Häder, D., Ilyas, M., Longstreth, J., Lucas, R., Madronich, S., McKenzie, R., Neale, R., Norval, M., Pandey, K., Paul, N., Redhwi, H., Robinson, S., Rose, K., Shao, M., Sinha, R., Solomon, K., Sulzberger, B., Takizawa, Y., Torikai, A., Tourpali, K., Williamson, C., Wilson, S., Wängberg, S., Worrest, R., Young, A., Zepp, R., Andrady, A., Aucamp, P., Austin, A., Bais, A., Ballaré, C., Barnes, P., Bernhard, G., Björn, L., Bornman, Janet, Erickson, D., De Gruijl, F., Häder, D., Ilyas, M., Longstreth, J., Lucas, R., Madronich, S., McKenzie, R., Neale, R., Norval, M., Pandey, K., Paul, N., Redhwi, H., Robinson, S., Rose, K., Shao, M., Sinha, R., Solomon, K., Sulzberger, B., Takizawa, Y., Torikai, A., Tourpali, K., Williamson, C., Wilson, S., Wängberg, S., Worrest, R., Young, A., and Zepp, R.

Abstract

The Environmental Effects Assessment Panel (EEAP) is one of three Panels that regularly informs the Parties (countries) to the Montreal Protocol on the effects of ozone depletion and the consequences of climate change interactions with respect to human health, animals, plants, biogeochemistry, air quality, and materials. The Panels provide a detailed assessment report every four years. The most recent 2014 Quadrennial Assessment by the EEAP was published as a special issue of seven papers in 2015 (Photochem. Photobiol. Sci., 2015, 14, 1-184). The next Quadrennial Assessment will be published in 2018/2019. In the interim, the EEAP generally produces an annual update or progress report of the relevant scientific findings. The present progress report for 2015 assesses some of the highlights and new insights with regard to the interactive nature of the effects of UV radiation, atmospheric processes, and climate change.

Published
2016

33. Evidence for an earlier greenhouse cooling effect in the stratosphere before 1980 over the Northern Hemisphere

Author

Zerefos, C.S. Tourpali, K. Zanis, P. Eleftheratos, K. Repapis, C. Goodman, A. Wuebbles, D. Isaksen, I.S.A. Luterbacher, J.

Abstract

This study provides a new look at the observed and calculated long-term temperature changes from the lower troposphere to the lower stratosphere since 1958 over the Northern Hemisphere. The data sets include the NCEP/NCAR reanalysis, the Free University of Berlin (FU-Berlin) and the RICH radiosonde data sets as well as historical simulations with the CESM1-WACCM global model participating in CMIP5. The analysis is mainly based on monthly layer mean temperatures derived from geopotential height thicknesses in order to take advantage of the use of the independent FU-Berlin stratospheric data set of geopotential height data since 1957. This approach was followed to extend the records for the investigation of the stratospheric temperature trends to the earliest possible time. After removing the natural variability with an autoregressive multiple regression model our analysis shows that the period 1958-2011 can be divided into two distinct sub-periods of long-term temperature variability and trends: before and after 1980. By calculating trends for the summer time to reduce interannual variability, the two periods are as follows. From 1958 until 1979, a non-significant trend (0.06 ± 0.06 °C decade-1 for NCEP) and slightly cooling trends (-0.12 ± 0.06 °C decade-1 for RICH) are found in the lower troposphere. The second period from 1980 to the end of the records shows significant warming (0.25 ± 0.05 °C decade-1 for both NCEP and RICH). Above the tropopause a significant cooling trend is clearly seen in the lower stratosphere both in the pre-1980 period (-0.58 ± 0.17 °C decade -1 for NCEP,-0.30 ± 0.16 °C decade-1 for RICH and-0.48 ± 0.20 °C decade-1 for FU-Berlin) and the post-1980 period (-0.79 ± 0.18 °C decade-1 for NCEP,-0.66 ± 0.16 °C decade-1 for RICH and-0.82 ± 0.19 °C decade-1 for FU-Berlin). The cooling in the lower stratosphere persists throughout the year from the tropics up to 60° N. At polar latitudes competing dynamical and radiative processes reduce the statistical significance of these trends. Model results are in line with reanalysis and the observations, indicating a persistent cooling (-0.33 °C decade-1) in the lower stratosphere during summer before and after 1980; a feature that is also seen throughout the year. However, the lower stratosphere CESM1-WACCM modelled trends are generally lower than reanalysis and the observations. The contrasting effects of ozone depletion at polar latitudes in winter/spring and the anticipated strengthening of the Brewer-Dobson circulation from man-made global warming at polar latitudes are discussed. Our results provide additional evidence for an early greenhouse cooling signal in the lower stratosphere before 1980, which appears well in advance relative to the tropospheric greenhouse warming signal. The suitability of early warning signals in the stratosphere relative to the troposphere is supported by the fact that the stratosphere is less sensitive to changes due to cloudiness, humidity and man-made aerosols. Our analysis also indicates that the relative contribution of the lower stratosphere versus the upper troposphere low-frequency variability is important for understanding the added value of the long-term tropopause variability related to human-induced global warming. © 2014 Author(s).

Published
2014

34. Solar Signals in CMIP-5 Simulations: The Ozone Response

Author

Hood, L. L., Misios, S., Mitchell, D. M., Rozanov, E., Gray, L. J., Tourpali, K., Matthes, Katja, Schmidt, H., Chiodo, G., Thieblemont, Remi, Shindell, D., Krivolutsky, A., Hood, L. L., Misios, S., Mitchell, D. M., Rozanov, E., Gray, L. J., Tourpali, K., Matthes, Katja, Schmidt, H., Chiodo, G., Thieblemont, Remi, Shindell, D., and Krivolutsky, A.

Abstract

A multiple linear regression statistical method is applied to model data taken from the Coupled Model Intercomparison Project, phase 5 (CMIP-5) to estimate the 11-yr solar cycle responses of stratospheric ozone, temperature, and zonal wind during the 1979-2005 period. The analysis is limited to the six CMIP-5 models that resolve the stratosphere (high-top models) and that include interactive ozone chemistry. All simulations assumed a conservative 11-yr solar spectral irradiance (SSI) variation based on the NRL model. These model responses are then compared to corresponding observational estimates derived from two independent satellite ozone profile data sets and from ERA Interim Reanalysis meteorological data. The models exhibit a range of 11-yr responses with three models (CESM1-WACCM, MIROC-ESM-CHEM, and MRI-ESM1) yielding substantial solar-induced ozone changes in the upper stratosphere that compare favorably with available observations. The remaining three models do not, apparently because of differences in the details of their radiation and photolysis rate codes. During winter in both hemispheres, the three models with stronger upper stratospheric ozone responses produce relatively strong latitudinal gradients of ozone and temperature in the upper stratosphere that are associated with accelerations of the polar night jet under solar maximum conditions. This behavior is similar to that found in the satellite ozone and ERA Interim data except that the latitudinal gradients tend to occur at somewhat higher latitudes in the models. The sharp ozone gradients are dynamical in origin and assist in radiatively enhancing the temperature gradients, leading to a stronger zonal wind response. These results suggest that simulation of a realistic solar-induced variation of upper stratospheric ozone, temperature and zonal wind in winter is possible for at least some coupled climate models even if a conservative SSI variation is adopted.

Published
2015
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35. Solar Signals in CMIP-5 Simulations: The Stratospheric Pathway

Author

Mitchell, D. M., Misios, S., Gray, L. J., Tourpali, K., Matthes, Katja, Hood, L., Schmidt, H., Chiodo, G., Thieblemont, Remi, Rozanov, E., Shindell, D., Krivolutsky, A., Mitchell, D. M., Misios, S., Gray, L. J., Tourpali, K., Matthes, Katja, Hood, L., Schmidt, H., Chiodo, G., Thieblemont, Remi, Rozanov, E., Shindell, D., and Krivolutsky, A.

Abstract

The 11-year solar cycle component of climate variability is assessed in the historical simulations of models taken from the Coupled Model Inter-comparison Project, phase 5 (CMIP-5). Multiple linear regression is applied to estimate the zonal-temperature, −wind and annular mode responses to a typical solar cycle, with a focus on both the stratosphere and the stratospheric influence on the surface over the period ∼1850-2005. The analysis is performed on all CMIP-5 models, but focuses on the 13 CMIP-5 models that resolve the stratosphere (high-top models), and compares the simulated solar cycle signature with reanalyses data. The 11-year solar cycle component of climate variability is found to be weaker in terms of magnitude and latitudinal gradient around the stratopause in the models than in reanalysis. The peak in temperature in the lower equatorial stratosphere (∼70 hPa) reported in some studies is found in the models to depend on the length of the analysis period, with the last 30 years yielding the strongest response. A modification of the Polar Jet Oscillation (PJO) in response to the 11-year solar cycle is not robust across all models, but is more apparent in models with high spectral resolution in the shortwave. The PJO evolution is slower in the models, leading to a stronger response during February, whereas observations indicate it to be weaker. In early winter, the magnitudes of the modelled response is more consistent with observations when only data from 1979–2005 is considered. The observed North Pacific high-pressure surface response during solar maximum is only simulated in some models, of which there are no distinguishing model characteristics. The lagged North Atlantic surface response is reproduced in both high- and low-top models, but is more prevalent in the former. In both cases, the magnitude of the response is generally lower than in observations.

Published
2015
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36. Environmental effects of ozone depletion and its interactions with climate change: 2014 assessment Executive summary

Author

Andrady, A., Aucamp, P., Austin, A., Bais, A., Ballaré, C., Barnes, P., Bernhard, G., Bornman, Janet, Caldwell, M., De Gruijl, F., Erickson, D., Flint, S., Gao, K., Gies, P., Häder, D., Ilyas, M., Longstreth, J., Lucas, R., Madronich, S., McKenzie, R., Neale, R., Norval, M., Pandy, K., Paul, N., Rautio, M., Redhwi, H., Robinson, S., Rose, K., Shao, M., Sinha, R., Solomon, K., Sulzberger, B., Takizawa, Y., Tang, X., Torikai, A., Tourpali, K., Van Der Leun, J., Wängberg, S., Williamson, C., Wilson, S., Worrest, R., Young, A., Zepp, R., Andrady, A., Aucamp, P., Austin, A., Bais, A., Ballaré, C., Barnes, P., Bernhard, G., Bornman, Janet, Caldwell, M., De Gruijl, F., Erickson, D., Flint, S., Gao, K., Gies, P., Häder, D., Ilyas, M., Longstreth, J., Lucas, R., Madronich, S., McKenzie, R., Neale, R., Norval, M., Pandy, K., Paul, N., Rautio, M., Redhwi, H., Robinson, S., Rose, K., Shao, M., Sinha, R., Solomon, K., Sulzberger, B., Takizawa, Y., Tang, X., Torikai, A., Tourpali, K., Van Der Leun, J., Wängberg, S., Williamson, C., Wilson, S., Worrest, R., Young, A., and Zepp, R.

Published
2015

39. Ozone variations derived by a chemical transport model

Author

Eleftheratos, K. Isaksen, I. Zerefos, C. Nastos, P. Tourpali, K. Rognerud, B.

Abstract

The results of a comparison between monthly mean ozone column variations calculated from the chemical transport model Oslo CTM2 and those derived from solar backscatter ultraviolet (SBUV) satellite observations are presented for the period 1998-2009. Monthly mean total ozone derived from improved model simulations were used to compute monthly zonal means over 10 latitude zones over the northern and southern hemispheres. Ozone column variations from Oslo CTM2 are highly correlated with SBUV retrievals at all latitude zones. Equatorial zonal winds at 30 hPa were used as index to study the impact of quasi-biennial oscillation (QBO) on ozone. Correlations between modeled ozone and the QBO were found to be the order of +0.8 in the tropics. The impact of QBO was most pronounced at equatorial latitudes with amplitudes of +4 to -4 %. Seasonal variations in surface ozone and tropospheric ozone column calculated by the model are also presented. © 2013 Springer Science+Business Media Dordrecht.

Published
2013

41. Evidence of a possible turning point in solar UV-B over Canada, Europe and Japan

Author

Zerefos, C.S. Tourpali, K. Eleftheratos, K. Kazadzis, S. Meleti, C. Feister, U. Koskela, T. Heikkilä, A.

Abstract

This study examines the long-term variability of UV solar irradiances at 305 nm and 325 nm over selected sites in Canada, Europe and Japan. Site selection was restricted to the availability of the most complete UV spectroradiometric datasets during the period 1990-2011. The analysis includes the long-term variability of total ozone, aerosol optical depth and cloud fraction at the sites studied. The results, based on observations and modeling, suggest that over Canada, Europe and Japan the period under study can be divided into three sub-periods of scientific merit: the first period (1991-1994) is the period perturbed by the Pinatubo volcanic eruption, during which excess volcanic aerosol has enhanced the "conventional" amplification factor of UV-B at ground level by an additional factor that depends on solar elevation. The increase of the UV-B amplification factor is the result of enhanced scattering processes caused by the injection of huge amounts of volcanic aerosols during the perturbed period. The second period (1995-2006) is characterized by a 0.14% yr -1 increase in total ozone and an increasing trend in spectral irradiance by 0.94% yr -1 at 305 nm and 0.88% yr -1 at 325 nm. That paradox was caused by the significant decline of the aerosol optical depth by more than 1% yr -1 (the "brightening" effect) and the absence of any statistically significant trend in the cloud fraction. The third period (2007-2011) shows statistically significant evidence of a slowdown or even a turning point in the previously reported upward UV-B trends over Canada, Europe and Japan. © 2012 Author(s).

Published
2012

42. Stratospheric Ozone and Surface Ultraviolet Radiation

Author

Douglass, A., Fioletov, V., Godin-Beekmann, S., Müller, R., Stolarski, R. S., Webb, A., Arola, A., Burkholder, J. B., Burrows, J. P., Chipperfield, M. P., Cordero, R., David, C., den Outer, P. N., Diaz, S. B., Flynn, L. E., Hegglin, M., Herman, J. R., Huck, P., Janjai, s., Janosi, I. M., Kryscin, J. W., Liu, Y., Logan, J., Matthes, Katja, McKenzie, R. L., Muthama, N. J., Petropavlovskikh, I., Pitts, M., Ramachandran, S., Rex, M., Salawitch, R. J., Sinnhuber, B.-M., Staehelin, J., Strahan, S., Tourpali, K., Valverde-Canossa, J., Vigouroux, C., Bodeker, G. E., Canty, T., De Backer, H., Demoulin, P., Feister, U., Frith, S. M., Grooß, J.-U., Hase, F., Klyft, J., Koide, T., Kurylo, M. J., Loyola, D., McLinden, C. A., Megretskaia, I. A., Nair, P. J., Palm, M., Papanastasiou, D., Poole, L. R., Schneider, M., Schofield, R., Slaper, H., Steinbrecht, W., Tegtmeier, Susann, Terao, Y., Tilmes, S., Vyushin, D. I., Weber, M., and Yang, E.-S.

Published
2011

43. Present climate trend analysis of the Etesian winds in the Aegean Sea

Author

Poupkou, A. Zanis, P. Nastos, P. Papanastasiou, D. Melas, D. Tourpali, K. Zerefos, C.

Abstract

The main objective of the present study is to perform a trend analysis and investigate the possible changes in the frequency and wind intensity of the Etesians during June to September of the years 1979 to 2009. The analysis is based mainly on the use of Reanalysis-1 data from the National Centers for Environmental Prediction/National Center for Atmospheric Research. The results are indicative of negative trends in the frequency and wind speed (WS) of the Etesians. During the 31-year period studied, the total number of Etesian days from June to September decreased by about 4.6 days, while the monthly maximum intensity of the daily WS was reduced by almost 1 m s-1. The above indications are strengthened by similar results derived from the trend analysis of observational wind data in the central Aegean for the years 1955 to 2002. The negative trend in the frequency of the Etesian days could be explained by a decreasing trend in the pressure gradient between the central and southern Europe high-pressure center and the Middle East low-pressure center, which cause the Etesians system. In the study, a possible association between the Southern Oscillation and the Etesian winds is also revealed. The negative trend in the frequency and WS of the Etesian winds could imply a reduced cooling mechanism in the eastern Mediterranean in the summer period due to climate change. © 2011 Springer-Verlag.

Published
2011

45. Solar signals in CMIP‐5 simulations: the ozone response

Author

Hood, L. L., primary, Misios, S., additional, Mitchell, D. M., additional, Rozanov, E., additional, Gray, L. J., additional, Tourpali, K., additional, Matthes, K., additional, Schmidt, H., additional, Chiodo, G., additional, Thiéblemont, R., additional, Shindell, D., additional, and Krivolutsky, A., additional

Published
2015
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46. Clear sky UV simulations for the 21st century based on ozone and temperature projections from Chemistry-Climate Models

Author

Tourpali, K. Bais, A.F. Kazantzidis, A. Zerefos, C.S. Akiyoshi, H. Austin, J. Brühl, C. Butchart, N. Chipperfield, M.P. Dameris, M. Deushi, M. Eyring, V. Giorgetta, M.A. Kinnison, D.E. Mancini, E. Marsh, D.R. Nagashima, T. Pitari, G. Plummer, D.A. Rozanov, E. Shibata, K. Tian, W.

Abstract

We have estimated changes in surface solar ultraviolet (UV) radiation under cloud free conditions in the 21st century based on simulations of 11 coupled Chemistry-Climate Models (CCMs). The total ozone columns and vertical profiles of ozone and temperature projected from CCMs were used as input to a radiative transfer model in order to calculate the corresponding erythemal irradiance levels. Time series of monthly erythemal irradiance received at the surface during local noon are presented for the period 1960 to 2100. Starting from the first decade of the 21st century, the surface erythemal irradiance decreases globally as a result of the projected stratospheric ozone recovery at rates that are larger in the first half of the 21st century and smaller towards its end. This decreasing tendency varies with latitude, being more pronounced over areas where stratospheric ozone.

Published
2009

47. Clear sky UV simulations for the 21st century based on ozone and temperature projections from Chemistry-Climate Models

Author

Tourpali, K., Bais, A.F., Kazantzidis, A., Zerefos, C.S., Akiyoshi, H., Avngaard, M., Austin, J., Brühl, C., Butchart, N., Chipperfield, M.P., Dameris, Martin, Deushi, M., Giorgetta, Marco, Eyring, V., Kinnison, Doug, Mancini, Eva, Marsh, D.R., Nagashima, T., Pitari, Giovanni, Plummer, D.A., Rozanov, Eugene, Shibata, K., and Tian, W.

Subjects
Atmospheric Science, Ozone, media_common.quotation_subject, Irradiance, Noon, Atmospheric sciences, lcsh:QC1-999, Latitude, lcsh:Chemistry, chemistry.chemical_compound, ozone, Atmospheric radiative transfer codes, lcsh:QD1-999, chemistry, Sky, Climatology, future evolution, Ozone layer, stratosphere, Climate model, Dynamik der Atmosphäre, lcsh:Physics, CCMs, media_common
Abstract

We have estimated changes in surface solar ultraviolet (UV) radiation under cloud free conditions in the 21st century based on simulations of 11 coupled Chemistry-Climate Models (CCMs). The total ozone columns and vertical profiles of ozone and temperature projected from CCMs were used as input to a radiative transfer model in order to calculate the corresponding erythemal irradiance levels. Time series of monthly erythemal irradiance received at the surface during local noon are presented for the period 1960 to 2100. Starting from the first decade of the 21st century, the surface erythemal irradiance decreases globally as a result of the projected stratospheric ozone recovery at rates that are larger in the first half of the 21st century and smaller towards its end. This decreasing tendency varies with latitude, being more pronounced over areas where stratospheric ozone has been depleted the most after 1980. Between 2000 and 2100 surface erythemal irradiance is projected to decrease over midlatitudes by 5 to 15%, while at the southern high latitudes the decrease is twice as much. In this study we have not included effects from changes in cloudiness, surface reflectivity and tropospheric aerosol loading, which will likely be affected in the future due to climate change. Consequently, over some areas the actual changes in future UV radiation may be different depending on the evolution of these parameters., Atmospheric Chemistry and Physics, 9 (4), ISSN:1680-7375, ISSN:1680-7367

Published
2009

48. On the turnaround of stratospheric ozone trends deduced from the reevaluated Umkehr record of Arosa, Switzerland

Author

Zanis, P. Maillard, E. Staehelin, J. Zerefos, C. Kosmidis, E. Tourpali, K. Wohltmann, I.

Abstract

In this work, we investigate the issue of the turnaround in ozone trends of the recently homogenized Umkehr ozone record of Arosa, Switzerland, which is the longest Umkehr data set, extending from 1956 to date, using different statistical methods. All methods show statistically significant negative ozone trends from 1970 to 1995 in the upper stratosphere (above 32.6 km) throughout the course of the year as well as in the lower stratosphere (below 23.5 km) mainly during winter to spring, which can be partially attributed to dynamical changes. Over the recent period (1996-2004) the year-round trends in the lower stratosphere become positive and are more positive during the winter to spring period. The results also show changes in upper stratospheric ozone trends after 1996, which are, however, not statistically significant at 95% if aerosol correction is applied on the retrieved data. This lack of significant trend changes during the recent period in the upper stratosphere is regionally coherent with recent results derived from upper stratospheric ozone data recorded by lidars, microwave radiometers, and satellite instruments at an adjacent location. Although the positive change in trends after 1996 both for upper and lower stratospheric ozone is in line with the reduction of the emissions of ozone-depleting substances from the successful implementation of the Montreal Protocol and its amendments, we recommend, because of lack of significance for the upper stratospheric trends, repeating this analysis in a few years in order to overcome ambiguous results for documentation of the turnaround of upper stratospheric ozone. Copyright 2006 by the American Geophysical Union.

Published
2006

50. Solar activity-ozone relationships in the vertical distribution of ozone

Author

Zerefos, C.S. Tourpali, K. Balis, D.

Abstract

This paper studies the effect of long-term solar variability in the vertical ozone distribution using reanalysed observational data from three sources: ozonesondes, Umtehr and satellite. The analysis provides an extension of earlier work, which showed the amplitude of the solar activity effect in total column ozone to be more pronounced over the tropics, amounting to about 1-2% of the mean and confirmed by model calculations. The amplitude of the solar activity signal in the ozone profiles, as evidenced from satellite data analysis, amounts to about 2% of the mean ozone values in the middle and upper stratosphere over most latitudes. Exceptions are seen over the high latitudes of the Southern Hemisphere and over the tropics, were there appears to be a solar activity signal also in the lower stratosphere. These results were obtained after removing the natural variability and monthly trends from all datasets. © 2005 Taylor & Francis.

Published
2005

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