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1. Observing the Near‐Surface Properties of the Greenland Ice Sheet

Author

Scanlan, K. M., Rutishauser, A., Simonsen, S. B., Scanlan, K. M., Rutishauser, A., and Simonsen, S. B.

Abstract

Spaceborne radar altimetry over ice sheets has exclusively focused on assessing volume changes through changes in surface elevation. For use in mass balance calculations, these measurements are supplemented with surface property information derived from regional climate models with limited large‐scale observational validation. Simultaneously, the strength at which a radar signal is reflected from the surface contains information on these same near‐surface properties. Here we show that a quantitative interpretation of European (ESA) CryoSat‐2 and French/Indian (CNES/ISRO) SARAL surface echo powers yields timeseries of pan‐Greenland wavelength‐scale roughness and surface density. Individually, the CryoSat‐2 and SARAL results strive toward providing an observational lens to enhance our current understanding of the surface processes affecting ice sheet mass balance and validate their representation by computational models. Taken together, they highlight how diversity in currently operational and future radar satellite altimetry missions can shed light on near‐surface vertical heterogeneity.

Published
2023

2. Nationaal Programma Landelijk Gebied - webinar VNG, 19 september 2022

Author

Simonsen, S. and Simonsen, S.

Abstract

Er is een groeiend besef dat het huidige systeem van landgebruik en hoe we met bodem, water, natuur en klimaat omgaan niet langer kan worden volgehouden en er een transitie moet plaatsvinden. Dit alles is geen nieuws, maar de vraag blijft hoe we die transitie met elkaar gaan waarmaken? Daar gaat het Nationaal Programma Landelijk Gebied ons enorm bij helpen en daar gaat deze webinar over.

Published
2022

4. Late Permian–Early Triassic environmental changes recorded by multi-isotope (Re-Os-N-Hg) data and trace metal distribution from the Hovea-3 section, Western Australia

Author

Georgiev, S.V., Stein, H.J., Yang, G., Hannah, J.L., Böttcher, M.E., Grice, Kliti, Holman, Alex, Turgeon, S., Simonsen, S., Cloquet, C., Georgiev, S.V., Stein, H.J., Yang, G., Hannah, J.L., Böttcher, M.E., Grice, Kliti, Holman, Alex, Turgeon, S., Simonsen, S., and Cloquet, C.

Abstract

The temporal coincidence between the Late Permian mass extinction (LPME) and the emplacement of Siberian Trap basalts suggests a causal link between the two events. Here, we discuss stratigraphic changes of organic and inorganic (including isotopic) geochemical properties of marine sediments across the Permian–Triassic boundary (PTB) in the Hovea-3 core, Western Australia, a key PTB section in the southern Neo-Tethys ocean. These data are compared with published data from the Meishan section, southern China, and from the Opal Creek section in western Canada, providing a view of Tethys and Panthalassa changes at the PTB. Trace metal and N-isotopic data, together with organic matter properties suggest that anoxic conditions were established prior to the LPME, intensified close to the LPME, and continued with photic-zone euxinia into the Early Triassic. For the Hovea-3 section, Re-Os ages confirm Changhsingian (253.5 ± 1.4 Ma) deposition of the dated interval sampled immediately below the stratigraphic level characterized by major lithological and isotopic changes. Evaluation of Re-Os, N, and Hg elemental and isotopic data for Hovea-3 suggests that anoxic conditions in the latest Permian were generally unrelated to direct magmatic contributions. A major increase in the initial Os isotopic ratio of Lower Triassic shales suggest an ~8× increase in the Early Triassic continental runoff, based on moderately conservative assumptions for end-members contributing Os to the Permian–Triassic ocean. Comparison to other PTB sections confirms a global signal of increasing Re/Os ratios in the Late Permian, and major and long-lived changes in the isotopic composition of the post-extinction ocean. A distinct peak in Hg concentrations carrying a volcanic isotopic signature, also identified in other PTB sections, likely represents a major pulse of Siberian Trap volcanism. This Hg peak in the Hovea-3 section, however, is detected above the stratigraphic level containing multiple other w

Published
2020

6. Euthanasia and assisted suicide in patients with personality disorders: a review of current practice and challenges

Author

Mehlum, L, Schmahl, C, Berens, A, Doering, S, Hutsebaut, J, Kaera, A, Kramer, U, Moran, P, Renneberg, B, Ribaudi, J, Simonsen, S, Swales, M, Taubner, S, di Giacomo, E, Mehlum, Lars, Schmahl, Christian, Berens, Ann, Doering, Stephan, Hutsebaut, Joost, Kaera, Andres, Kramer, Ueli, Moran, Paul Anthony, Renneberg, Babette, Ribaudi, Joaquim Soler, Simonsen, Sebastian, Swales, Michaela, Taubner, Svenja, di Giacomo, Ester, Mehlum, L, Schmahl, C, Berens, A, Doering, S, Hutsebaut, J, Kaera, A, Kramer, U, Moran, P, Renneberg, B, Ribaudi, J, Simonsen, S, Swales, M, Taubner, S, di Giacomo, E, Mehlum, Lars, Schmahl, Christian, Berens, Ann, Doering, Stephan, Hutsebaut, Joost, Kaera, Andres, Kramer, Ueli, Moran, Paul Anthony, Renneberg, Babette, Ribaudi, Joaquim Soler, Simonsen, Sebastian, Swales, Michaela, Taubner, Svenja, and di Giacomo, Ester

Abstract

Background: Over the last two decades an increasing number of countries have legalized euthanasia and physician-assisted suicide (EAS) leading to considerable debate over the inherent ethical dilemmas. Increasing numbers of people with personality disorders, faced with unbearable suffering, have requested and received assistance in terminating their lives. EAS in people with personality disorders has, however, received very sparse attention from clinicians and researchers. In this paper, we examine the literature on the practice and prevalence of EAS in people with personality disorders to date and discuss the associated challenges for research and practice. Methods: Narrative review of the literature combined with the authors' collective experience and knowledge of personality disorders. Results: In six of the eight countries where EAS is currently legal, mental disorders are accepted as disorders for which EAS may be granted. In four of these countries, EAS in minors with mental disorders is also accepted. Our literature search resulted in 9 papers on the subject of EAS in people with personality disorders. These studies suggest that most clinicians who grant EAS have indeed perceived their patients' suffering as chronic, unbearable and untreatable without prospect of improvement. The majority of patients with personality disorders had tried some form of psychotherapy, but very few had received any of the relevant evidence-based treatments. The decision to grant EAS based on a perception of the patient's illness as being untreatable with no prospect of improvement, could, thus, in many cases fail to meet the due care criteria listed in EAS laws. People with personality disorders more often wish for death for extended periods of time than people without these disorders. However, there is ample empirical data to show that suicidal tendencies and behaviour can be treated and that they fluctuate rapidly over time. Conclusions: In light of our findings, we believe that

Published
2020

8. Avoidant and narcissistic personality disorder

Author

Bateman, A, Fonagy, P, Bateman, A ( A ), Fonagy, P ( P ), Simonsen, S, Euler, S, Bateman, A, Fonagy, P, Bateman, A ( A ), Fonagy, P ( P ), Simonsen, S, and Euler, S

Published
2019

10. 25 Year Time Series of Multiple-Satellite Ice Sheet Changes: the ESA Climate Change Initiative

Author

Forsberg, R., Sørensen, L., Simonsen, S., Barletta, V., Kusk, A., Nagler, T., Hetzenecker , M., Shepherd , A., Groh, A., Solgaard, A., Engdahl, M., Forsberg, R., Sørensen, L., Simonsen, S., Barletta, V., Kusk, A., Nagler, T., Hetzenecker , M., Shepherd , A., Groh, A., Solgaard, A., and Engdahl, M.

Abstract

Understanding the long-term changes in the ice sheets of Greenland and Antarctica has global climate significance, especially on long term global sea level rise predictions. Having validated satellite data on current and recent past changes of the ice sheets are crucial for validating climate and earth system models, and give good opportunities for space geodesy to play an important role for society. Under the ESA Climate Change Initiative two projects on Greenland and Antarctica ice sheet changes are making past and present space measurements of the ice sheets available for use by scientists, stakeholders and the general public. The data are part of a large set of ECV’s (Essential Climate Variables) made available by the ESA Climate Initiative, as a contribution to the global Climate Observing System. The ECV data produced include detailed elevation change data from radar altimetry ice flow velocities from synthetic aperture radar missions, mass changes from GRACE, as well as data of glacier and ice shelf grounding lines and (for Greenland) glacier calving front locations from radar and optical data. In the poster we highlight current CCI results on changes in Greenland, with special focus on 25 year elevation changes from ERS-1, ERS-2, Envisat and CryoSat, as well as the Greenland-wide velocity mapping, and the GRACE mass change results.

Published
2018

11. Greenland CCI Surface Elevation Change Products from Cryosat-2 and SARAL/ALtiKa

Author

Simonsen, S., Khvorostovsky, K., Sandberg Sørensen, L., Forsberg, R., Simonsen, S., Khvorostovsky, K., Sandberg Sørensen, L., and Forsberg, R.

Abstract

A long, unbroken sequence of satellite altimetry elevation changes is an essential climate variable. Here,we present the surface elevation change (SEC) record provided in the ESA Greenland ice sheet CCI project, as 5-year running means spanning back to 1992. The 5-year running mean is chosen to show the imprint of climate change on the Greenland ice sheet surface elevation change and limits the imprint of weather variability. We mainly focus on the novel results from ESA's Cryosat- 2 and the French-Indian SARAL/ALtiKa satellite, as this latest generation of radar altimeters provides new opportunities for monitoring Greenland ice sheet SEC. The orbit of Cryosat-2 enables the generation of a higher temporal-resolution data product from Ku-band radar altimetry; a 2-year running mean SEC. This 2-year product shows the inter-annual variability in weather and its imprint in surface elevation. The observational period of SARAL/ALtiKa satellite has now matured, and an experimental SEC product from Ka-band altimetry is being provided in the Greenland ice sheet CCI. The Kaband radar altimetry is less subject to surface penetration in firn covered areas, and map changes in snowfall in the interior region of the Greenland ice sheet. The Greenland ice sheet CCI now provides 11 maps of Greenland SEC generated from Cryosat-2 or SARAL/ALtiKa data. All giving insight into the complex nature of the changing Greenland ice sheet. The emerging patterns from comparing both Cryosat-2 5- year vs. 2-year SEC and Ku-band vs. Ka-band SEC may relate to the interplay between the surface mass balance and internal ice sheet dynamics.

Published
2018

12. Changes in Antarctic Ice Sheet Surface Elevation from a Quarter-century of Combined Radar and Laser Altimetry

Author

Nilsson, J., Paolo, F., Gardner, A., Bjerregaard Simonsen, S., Nilsson, J., Paolo, F., Gardner, A., and Bjerregaard Simonsen, S.

Abstract

Satellite altimetry provides the longest continuous record of elevation change for assessing the mass balance of the Antarctic Ice Sheet, providing a unique opportunity to observe the ice sheet's response to changes in atmosphere and ocean over the last few decades. The accuracy of altimetry-measured elevation change, from which this mass balance is derived, is of vital importance for quantifying Antarctica's contribution to sea-level rise, and for understanding the physical processes governing changes of the ice sheet. Studies have shown that the rate of Antarctica's mass loss has accelerated over the last decade, largely a result of accelerated ice flow from the Amundsen Sea sector of West Antarctica. Not all areas of the ice sheet are thinning however. Increases in precipitation have resulted in rapid thickening over parts of East Antarctica, especially in Dronning Maud Land. A key question is how these relatively recent changes contrast against the observed longer-term trend and variability. Observations from overlapping satellite altimeter mission over the last three decades can help to answer this question. Here, we have developed a novel framework for cross-calibrating and synthesizing multimission altimetry records, with a further emphasis on generating state-of-the-art corrections for issues affecting the altimeter measurement (such as surface slope and variations in surface scattering) in order to increase the reliability and accuracy of the full altimetry record. The framework allows us to construct consistent time series at fine spatial and temporal scales for the majority of the ice sheet, with a corresponding assessment of the overall uncertainty of the solutions. We present results detailing the complex long-term pattern of elevation change, observed by the altimeters, and discuss the current improvement and imitations of the altimeter record. This effort will allow us to improve upon existing records of the long-term evolution of the Anta

Published
2018

13. Dual Frequency Radar Altimetry-Measuring Greenland Firn Properties from Space

Author

Simonsen, S., Sørensen, L. S., Stenseng, L., Forsberg, R., Simonsen, S., Sørensen, L. S., Stenseng, L., and Forsberg, R.

Abstract

For the last eight years, the ESA CryoSat-2 Ku-band radar altimeter has been measuring the elevation of the Greenland Ice Sheet. Ku-band enables surface penetration at firn covered areas, which hampers the direct interpretation of surface elevation change from Cryosat-2 and other Ku-band altimeters. However, mapping the changes in penetration depth can provide information on firn stratigraphy. If the physical surface (snow/air interface) of the ice sheet can be determined from an independent source, the differences in the two surfaces may directly be linked to the penetration depth of Ku-band radar altimetry, and hence to the temperature and density of the upper firn. Here, we use independent estimates of the surface elevation changes from the Ka-band radar altimeter (AltiKa) operated onboard the French/Indian satellite SARAL. The higher frequency of Ka-band reduces surface penetration to a minimum and combining the records from both Ku- and Ka-band satellites are the key to utilizing the full potential of CryoSat-2. Hence, providing both high spatial-resolution surface elevation change and insights into changes in firn properties. The interpretation of dual-frequency altimetry is supported by firn modeling. The model has previously been applied to gain mass balance from ICESat and is now updated with a conceptual model for Ku-band radar penetration. Ultimately, a dual-band radar altimeter operating from space may provide ice sheet wide measurements of firn densities, a key parameter in determining direct ice mass balance from satellite altimetry.

Published
2018

14. ESA CryoVEx/EU ICE-ARC 2016 - Airborne field campaign with ASIRAS radar and laser scanner over Austfonna, Fram Strait and the Wandel Sea

Author

Skourup, H., Simonsen, S. B., Sørensen, L. Sandberg, Helm, V., Hvidegaard, S. M., Di Bella, A., Forsberg, R., Skourup, H., Simonsen, S. B., Sørensen, L. Sandberg, Helm, V., Hvidegaard, S. M., Di Bella, A., and Forsberg, R.

Abstract

This report outlines the airborne field operations with the ESA airborne Ku‐band interferometric radar (ASIRAS) and coincident airborne laser scanner (ALS) to acquire gridded data over Austfonna ice cap in Svalbard for CryoSat‐2 validation, first direct Sentinel‐3A underflight over sea ice in the Fram Strait and additional repeat some previously flown sea tracks in Fram Strait and the Wandel Sea. Vertical photography was acquired during sea ice flights to support analysis of ASIRAS and ALS observations. The airborne campaign took place April 4‐16, 2016, operating out of Svalbard and StationNord. The campaign was coordinated by DTU Space using the Norlandair Twin Otter (TF‐POF). It was partly funded by ESA CryoVEx (Austfonna ice cap flights) and partly by EU FP7 project ICE‐ARC (Fram Strait and Wandel sea ice flights). The mobilization costs were shared equally between the projects.The CryoVEx/ICE‐ARC 2016 campaign was a success and the processed data is of high quality. Preliminary comparisons between CryoSat‐2 and ALS data at Austfonna ice cap, proves the concept of using a gridded ALS data set of lines parallel to CryoSat‐2 ground tracks in areas with varying topography. First direct comparisons of Sentinel‐3A and ALS also show consistent results.

Published
2018

15. Interleukin (IL)-17A and IL-22-producing neutrophils in psoriatic skin

Author

Dyring-Andersen, B, Honoré, T V, Madelung, A, Bzorek, M, Simonsen, S, Clemmensen, S N, Clark, R A, Borregaard, N, Skov, L, Dyring-Andersen, B, Honoré, T V, Madelung, A, Bzorek, M, Simonsen, S, Clemmensen, S N, Clark, R A, Borregaard, N, and Skov, L

Published
2017

16. CryoSat Land Ice Product Validation within the CryoVal-LI project

Author

Sandberg Sørensen, L., Baker, S., Csatho, B., Forsberg, R., Gourmelen, N., Helm, Veit, Langley, K., Martinez, B., Nienow, P., Schrama, E., Shepherd, A., Davidson, M., Simonsen, S. B., Sandberg Sørensen, L., Baker, S., Csatho, B., Forsberg, R., Gourmelen, N., Helm, Veit, Langley, K., Martinez, B., Nienow, P., Schrama, E., Shepherd, A., Davidson, M., and Simonsen, S. B.

Abstract

The main objective of the ESA funded CryoVal-LI project has been to identify and quantify the error sources for the CryoSat-2 mission over land ice. This has been undertaken through the careful documentation of the possible error sources, the identification of suitable validation sites and the creation of a public database containing validation data for these areas from recent ground and airborne field campaigns. These sites also offer considerable potential as sites on which to focus future validation efforts. Through the utilization of these observational datasets, an extensive comparative analysis has been carried out in which Cryosat-2 data has been evaluated against airborne and in-situ data. A number of different Cryosat-2 data sets have been included in this analysis with the goal of testing the performance of different processing and retracking algorithms. A similar, but smaller validation analysis has also been carried out for ICESat data. Here, we present the results of these analyses and outline the conclusions reached. Based on the findings from the project, a set of recommendations for the design of future land-ice/satellite validation campaigns will be given. Furthermore, the outcome of the re-tracker inter-comparison will be used to advocate a set of optimal re-tracking algorithms for Cryosat-2 in the next generation of L2 products.

Published
2016

17. CryoSat Land Ice Product Validation within the CryoVal-LI project

Author

Sandberg Sørensen, L., Baker, S., Csatho, B., Forsberg, R., Gourmelen, N., Helm, Veit, Langley, K., Martinez, B., Nienow, P., Schrama, E., Shepherd, A., Davidson, M., Simonsen, S. B., Sandberg Sørensen, L., Baker, S., Csatho, B., Forsberg, R., Gourmelen, N., Helm, Veit, Langley, K., Martinez, B., Nienow, P., Schrama, E., Shepherd, A., Davidson, M., and Simonsen, S. B.

Abstract

The main objective of the ESA funded CryoVal-LI project has been to identify and quantify the error sources for the CryoSat-2 mission over land ice. This has been undertaken through the careful documentation of the possible error sources, the identification of suitable validation sites and the creation of a public database containing validation data for these areas from recent ground and airborne field campaigns. These sites also offer considerable potential as sites on which to focus future validation efforts. Through the utilization of these observational datasets, an extensive comparative analysis has been carried out in which Cryosat-2 data has been evaluated against airborne and in-situ data. A number of different Cryosat-2 data sets have been included in this analysis with the goal of testing the performance of different processing and retracking algorithms. A similar, but smaller validation analysis has also been carried out for ICESat data. Here, we present the results of these analyses and outline the conclusions reached. Based on the findings from the project, a set of recommendations for the design of future land-ice/satellite validation campaigns will be given. Furthermore, the outcome of the re-tracker inter-comparison will be used to advocate a set of optimal re-tracking algorithms for Cryosat-2 in the next generation of L2 products.

Published
2016

18. ESA CryoVEx 2014 - Airborne ASIRAS radar and laser scanner measurements during 2014 CryoVEx campaign in the Arctic

Author

Hvidegaard, S. M., Nielsen, J. E., Sørensen, L. Sandberg, Simonsen, S. B., Skourup, H., Forsberg, R., Helm, V., Bjerg, T., Hvidegaard, S. M., Nielsen, J. E., Sørensen, L. Sandberg, Simonsen, S. B., Skourup, H., Forsberg, R., Helm, V., and Bjerg, T.

Abstract

This report outlines the airborne field operations with the ESA airborne Ku‐band interferometric radar (ASIRAS), coincident airborne laser scanner (ALS) and vertical photography to acquire data over sea‐ and land ice along validation sites and CryoSat‐2 ground tracks. The airborne campaign was coordinated by DTU Space using the Norlandair Twin Otter (TF‐POF). The campaign consisted of two experiment periods: Mid‐march to early April and late April to mid‐May with focus on sea ice and land ice, respectively. The sea ice measurements covered several validation sites with sea ice camps located in the Beaufort Sea lead by US office of Naval Research (ONR) and north of Greenland as a dedicated ESA CryoVEx initiative. In addition, selected CryoSat‐2 ground tracks were under‐flown in the Lincoln Sea from CFS Alert, North of Greenland and Svalbard from St. Nord and Longyearbyen. Several of the flights in the Beaufort and Lincoln Sea were coordinated with Uni. of York (UY) lead Basler aircraft towing an electromagnetic (AEM/EM bird) sounder to obtain sea ice thickness and Operation IceBridge (OIB) NASA P‐3 carrying a variety of instruments for sea ice and snow retrievals. Land ice measurements were acquired over the Greenland ice sheet (the EGIG line and selected CryoSat‐ 2 ground tracks), together with Austfonna and Devon ice caps. At Austfonna and Devon ice caps ground teams measured ice and snow properties, and raised corner reflectors acting as a surface reference point in order to estimate the penetration depth of the ASIRAS radar. An opportunity site on the Greenland Ice Sheet was surveyed near Jakobshavn Isbræ. No other ground experiments were coordinated with the CryoVEx campaing on the Greenland Ice Sheet. The CryoVEx 2014 campaign was a success and the processed data is of high quality. The data set includes 13 CryoSat underflights covering distances from 25‐560 km. The preliminary comparisons to CryoSat‐2 data show the potential of the extensive dataset.

Published
2015

21. Eemian interglacial reconstructed from a Greenland folded ice core

Author

Dahl-Jensen, D., Albert, M. R., Aldahan, Ala, Azuma, N., Balslev-Clausen, D., Baumgartner, M., Berggren, Ann-Marie, Bigler, M., Binder, T., Blunier, T., Bourgeois, J. C., Brook, E. J., Buchardt, S. L., Buizert, C., Capron, E., Chappellaz, J., Chung, J., Clausen, H. B., Cvijanovic, I., Davies, S. M., Ditlevsen, P., Eicher, O., Fischer, H., Fisher, D. A., Fleet, L. G., Gfeller, G., Gkinis, V., Gogineni, S., Goto-Azuma, K., Grinsted, A., Gudlaugsdottir, H., Guillevic, M., Hansen, S. B., Hansson, M., Hirabayashi, M., Hong, S., Hur, S. D., Huybrechts, P., Hvidberg, C. S., Iizuka, Y., Jenk, T., Johnsen, S. J., Jones, T. R., Jouzel, J., Karlsson, N. B., Kawamura, K., Keegan, K., Kettner, E., Kipfstuhl, S., Kjaer, H. A., Koutnik, M., Kuramoto, T., Koehler, P., Laepple, T., Landais, A., Langen, P. L., Larsen, L. B., Leuenberger, D., Leuenberger, M., Leuschen, C., Li, J., Lipenkov, V., Martinerie, P., Maselli, O. J., Masson-Delmotte, V., McConnell, J. R., Miller, H., Mini, O., Miyamoto, A., Montagnat-Rentier, M., Mulvaney, R., Muscheler, R., Orsi, A. J., Paden, J., Panton, C., Pattyn, F., Petit, J. -R, Pol, K., Popp, T., Possnert, Göran, Prie, F., Prokopiou, M., Quiquet, A., Rasmussen, S. O., Raynaud, D., Ren, J., Reutenauer, C., Ritz, C., Rockmann, T., Rosen, J. L., Rubino, M., Rybak, O., Samyn, D., Sapart, C. J., Schilt, A., Schmidt, A. M. Z., Schwander, J., Schuepbach, S., Seierstad, I., Severinghaus, J. P., Sheldon, S., Simonsen, S. B., Sjolte, J., Solgaard, A. M., Sowers, T., Sperlich, P., Steen-Larsen, H. C., Steffen, K., Steffensen, J. P., Steinhage, D., Stocker, T. F., Stowasser, C., Sturevik, A. S., Sturges, W. T., Sveinbjornsdottir, A., Svensson, A., Tison, J. -L, Uetake, J., Vallelonga, P., van de Wal, R. S. W., van der Wel, G., Vaughn, B. H., Vinther, B., Waddington, E., Wegner, A., Weikusat, I., White, J. W. C., Wilhelms, F., Winstrup, M., Witrant, E., Wolff, E. W., Xiao, C., Zheng, J., Dahl-Jensen, D., Albert, M. R., Aldahan, Ala, Azuma, N., Balslev-Clausen, D., Baumgartner, M., Berggren, Ann-Marie, Bigler, M., Binder, T., Blunier, T., Bourgeois, J. C., Brook, E. J., Buchardt, S. L., Buizert, C., Capron, E., Chappellaz, J., Chung, J., Clausen, H. B., Cvijanovic, I., Davies, S. M., Ditlevsen, P., Eicher, O., Fischer, H., Fisher, D. A., Fleet, L. G., Gfeller, G., Gkinis, V., Gogineni, S., Goto-Azuma, K., Grinsted, A., Gudlaugsdottir, H., Guillevic, M., Hansen, S. B., Hansson, M., Hirabayashi, M., Hong, S., Hur, S. D., Huybrechts, P., Hvidberg, C. S., Iizuka, Y., Jenk, T., Johnsen, S. J., Jones, T. R., Jouzel, J., Karlsson, N. B., Kawamura, K., Keegan, K., Kettner, E., Kipfstuhl, S., Kjaer, H. A., Koutnik, M., Kuramoto, T., Koehler, P., Laepple, T., Landais, A., Langen, P. L., Larsen, L. B., Leuenberger, D., Leuenberger, M., Leuschen, C., Li, J., Lipenkov, V., Martinerie, P., Maselli, O. J., Masson-Delmotte, V., McConnell, J. R., Miller, H., Mini, O., Miyamoto, A., Montagnat-Rentier, M., Mulvaney, R., Muscheler, R., Orsi, A. J., Paden, J., Panton, C., Pattyn, F., Petit, J. -R, Pol, K., Popp, T., Possnert, Göran, Prie, F., Prokopiou, M., Quiquet, A., Rasmussen, S. O., Raynaud, D., Ren, J., Reutenauer, C., Ritz, C., Rockmann, T., Rosen, J. L., Rubino, M., Rybak, O., Samyn, D., Sapart, C. J., Schilt, A., Schmidt, A. M. Z., Schwander, J., Schuepbach, S., Seierstad, I., Severinghaus, J. P., Sheldon, S., Simonsen, S. B., Sjolte, J., Solgaard, A. M., Sowers, T., Sperlich, P., Steen-Larsen, H. C., Steffen, K., Steffensen, J. P., Steinhage, D., Stocker, T. F., Stowasser, C., Sturevik, A. S., Sturges, W. T., Sveinbjornsdottir, A., Svensson, A., Tison, J. -L, Uetake, J., Vallelonga, P., van de Wal, R. S. W., van der Wel, G., Vaughn, B. H., Vinther, B., Waddington, E., Wegner, A., Weikusat, I., White, J. W. C., Wilhelms, F., Winstrup, M., Witrant, E., Wolff, E. W., Xiao, C., and Zheng, J.

Abstract

Efforts to extract a Greenland ice core with a complete record of the Eemian interglacial (130,000 to 115,000 years ago) have until now been unsuccessful. The response of the Greenland ice sheet to the warmer-than-present climate of the Eemian has thus remained unclear. Here we present the new North Greenland Eemian Ice Drilling ('NEEM') ice core and show only a modest ice-sheet response to the strong warming in the early Eemian. We reconstructed the Eemian record from folded ice using globally homogeneous parameters known from dated Greenland and Antarctic ice-core records. On the basis of water stable isotopes, NEEM surface temperatures after the onset of the Eemian (126,000 years ago) peaked at 8 +/- 4 degrees Celsius above the mean of the past millennium, followed by a gradual cooling that was probably driven by the decreasing summer insolation. Between 128,000 and 122,000 years ago, the thickness of the northwest Greenland ice sheet decreased by 400 +/- 250 metres, reaching surface elevations 122,000 years ago of 130 +/- 300 metres lower than the present. Extensive surface melt occurred at the NEEM site during the Eemian, a phenomenon witnessed when melt layers formed again at NEEM during the exceptional heat of July 2012. With additional warming, surface melt might become more common in the future.

Published
2013
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22. Eemian interglacial reconstructed from a Greenland folded ice core

Author

Dahl-Jensen, D., Albert, M. R., Aldahan, A., Azuma, N., Balslev-Clausen, D., Baumgartner, M., Berggren, A. -M, Bigler, M., Binder, T., Blunier, T., Bourgeois, J. C., Brook, E. J., Buchardt, S. L., Buizert, C., Capron, E., Chappellaz, J., Chung, J., Clausen, H. B., Cvijanovic, I., Davies, S. M., Ditlevsen, P., Eicher, O., Fischer, H., Fisher, D. A., Fleet, L. G., Gfeller, G., Gkinis, V., Gogineni, S., Goto-Azuma, K., Grinsted, A., Gudlaugsdottir, H., Guillevic, M., Hansen, S. B., Hansson, Margareta, Hirabayashi, M., Hong, S., Hur, S. D., Huybrechts, P., Hvidberg, C. S., Iizuka, Yoshinori, Jenk, T., Johnsen, S. J., Jones, T. R., Jouzel, J., Karlsson, N. B., Kawamura, K., Keegan, K., Kettner, E., Kipfstuhl, S., Kjaer, H. A., Koutnik, M., Kuramoto, T., Koehler, P., Laepple, T., Landais, A., Langen, P. L., Larsen, L. B., Leuenberger, D., Leuenberger, M., Leuschen, C., Li, J., Lipenkov, V., Martinerie, P., Maselli, O. J., Masson-Delmotte, V., McConnell, J. R., Miller, H., Mini, O., Miyamoto, A., Montagnat-Rentier, M., Mulvaney, R., Muscheler, R., Orsi, A. J., Paden, J., Panton, C., Pattyn, F., Petit, J. -R, Pol, K., Popp, T., Possnert, G., Prie, F., Prokopiou, M., Quiquet, A., Rasmussen, S. O., Raynaud, D., Ren, J., Reutenauer, C., Ritz, C., Rockmann, T., Rosen, J. L., Rubino, M., Rybak, O., Samyn, D., Sapart, C. J., Schilt, A., Schmidt, A. M. Z., Schwander, J., Schuepbach, S., Seierstad, I., Severinghaus, J. P., Sheldon, S., Simonsen, S. B., Sjolte, J., Solgaard, A. M., Sowers, T., Sperlich, P., Steen-Larsen, H. C., Steffen, K., Steffensen, J. P., Steinhage, D., Stocker, T. F., Stowasser, C., Sturevik, A. S., Sturges, W. T., Sveinbjornsdottir, A., Svensson, A., Tison, J. -L, Uetake, J., Vallelonga, P., van de Wal, R. S. W., van der Wel, G., Vaughn, B. H., Vinther, B., Waddington, E., Wegner, A., Weikusat, I., White, J. W. C., Wilhelms, F., Winstrup, M., Witrant, E., Wolff, E. W., Xiao, C., Zheng, J., Dahl-Jensen, D., Albert, M. R., Aldahan, A., Azuma, N., Balslev-Clausen, D., Baumgartner, M., Berggren, A. -M, Bigler, M., Binder, T., Blunier, T., Bourgeois, J. C., Brook, E. J., Buchardt, S. L., Buizert, C., Capron, E., Chappellaz, J., Chung, J., Clausen, H. B., Cvijanovic, I., Davies, S. M., Ditlevsen, P., Eicher, O., Fischer, H., Fisher, D. A., Fleet, L. G., Gfeller, G., Gkinis, V., Gogineni, S., Goto-Azuma, K., Grinsted, A., Gudlaugsdottir, H., Guillevic, M., Hansen, S. B., Hansson, Margareta, Hirabayashi, M., Hong, S., Hur, S. D., Huybrechts, P., Hvidberg, C. S., Iizuka, Yoshinori, Jenk, T., Johnsen, S. J., Jones, T. R., Jouzel, J., Karlsson, N. B., Kawamura, K., Keegan, K., Kettner, E., Kipfstuhl, S., Kjaer, H. A., Koutnik, M., Kuramoto, T., Koehler, P., Laepple, T., Landais, A., Langen, P. L., Larsen, L. B., Leuenberger, D., Leuenberger, M., Leuschen, C., Li, J., Lipenkov, V., Martinerie, P., Maselli, O. J., Masson-Delmotte, V., McConnell, J. R., Miller, H., Mini, O., Miyamoto, A., Montagnat-Rentier, M., Mulvaney, R., Muscheler, R., Orsi, A. J., Paden, J., Panton, C., Pattyn, F., Petit, J. -R, Pol, K., Popp, T., Possnert, G., Prie, F., Prokopiou, M., Quiquet, A., Rasmussen, S. O., Raynaud, D., Ren, J., Reutenauer, C., Ritz, C., Rockmann, T., Rosen, J. L., Rubino, M., Rybak, O., Samyn, D., Sapart, C. J., Schilt, A., Schmidt, A. M. Z., Schwander, J., Schuepbach, S., Seierstad, I., Severinghaus, J. P., Sheldon, S., Simonsen, S. B., Sjolte, J., Solgaard, A. M., Sowers, T., Sperlich, P., Steen-Larsen, H. C., Steffen, K., Steffensen, J. P., Steinhage, D., Stocker, T. F., Stowasser, C., Sturevik, A. S., Sturges, W. T., Sveinbjornsdottir, A., Svensson, A., Tison, J. -L, Uetake, J., Vallelonga, P., van de Wal, R. S. W., van der Wel, G., Vaughn, B. H., Vinther, B., Waddington, E., Wegner, A., Weikusat, I., White, J. W. C., Wilhelms, F., Winstrup, M., Witrant, E., Wolff, E. W., Xiao, C., and Zheng, J.

Abstract

Efforts to extract a Greenland ice core with a complete record of the Eemian interglacial (130,000 to 115,000 years ago) have until now been unsuccessful. The response of the Greenland ice sheet to the warmer-than-present climate of the Eemian has thus remained unclear. Here we present the new North Greenland Eemian Ice Drilling ('NEEM') ice core and show only a modest ice-sheet response to the strong warming in the early Eemian. We reconstructed the Eemian record from folded ice using globally homogeneous parameters known from dated Greenland and Antarctic ice-core records. On the basis of water stable isotopes, NEEM surface temperatures after the onset of the Eemian (126,000 years ago) peaked at 8 +/- 4 degrees Celsius above the mean of the past millennium, followed by a gradual cooling that was probably driven by the decreasing summer insolation. Between 128,000 and 122,000 years ago, the thickness of the northwest Greenland ice sheet decreased by 400 +/- 250 metres, reaching surface elevations 122,000 years ago of 130 +/- 300 metres lower than the present. Extensive surface melt occurred at the NEEM site during the Eemian, a phenomenon witnessed when melt layers formed again at NEEM during the exceptional heat of July 2012. With additional warming, surface melt might become more common in the future., AuthorCount:133

Published
2013
Full Text
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23. Eemian interglacial reconstructed from a Greenland folded ice core

Author

Dahl-Jensen, D., Albert, M. R., Aldahan, A., Azuma, N., Balslev-Clausen, D., Baumgartner, M., Berggren, A.-M., Bigler, M., Binder, T., Blunier, T., Bourgeois, J. C., Brook, E. J., Buchardt, S. L., Buizert, C., Capron, E., Chappellaz, J., Chung, J., Clausen, H. B., Cvijanovic, I., Davies, S. M., Ditlevsen, P., Eicher, O., Fischer, H., Fisher, D. A., Fleet, L. G., Gfeller, G., Gkinis, V., Gogineni, S., Grinsted, A., Goto-Azuma, K., Gudlaugsdottir, H., Guillevic, M., Hansen, S. B., Hansson, M., Hirabayashi, M., Hong, S., Hur, S. D., Huybrechts, P., Hvidberg, C. S., Jenk, T., Iizuka, Y., Johnsen, S. J., Jones, T. R., Jouzel, J., Karlsson, N. B., Kawamura, K., Keegan, K., Kettner, E., Kipfstuhl, Sepp, Kjær, H. A., Koutnik, M., Kuramoto, T., Köhler, Peter, Laepple, Thomas, Landais, A., Langen, P. L., Larsen, L. B., Leuenberger, D., Leuenberger, M., Leuschen, C., Li, J., Lipenkov, V., Martinerie, P., Maselli, O. J., Masson-Delmotte, V., McConnell, J. R., Miller, Heinrich, Mini, O., Miyamoto, A., Montagnat-Rentier, M., Mulvaney, R., Muscheler, R., Paden, J., Orsi, A. J., Panton, C., Pattyn, F., Petit, J.-R., Pol, K., Popp, T., Possnert, G., Prié, F., Prokopiou, M., Quiquet, A., Rasmussen, S. O., Raynaud, D., Ren, J., Reutenauer, C., Ritz, C., Röckmann, T., Rosen, J. L., Rubino, M., Rybak, O., Samyn, D., Sapart, C. J., Schilt, A., Schmidt, A. M. Z., Schüpbach, S., Schwander, J., Seierstad, I., Severinghaus, J. P., Sheldon, S., Simonsen, S. B., Sjolte, J., Solgaard, A. M., Sowers, T., Sperlich, P., Steen-Larsen, H. C., Steffen, K., Steffensen, J. P., Steinhage, Daniel, Stocker, T. F., Stowasser, C., Sturevik, A. S., Sturges, W. T., Sveinbjörnsdottir, A., Svensson, A., Tison, J.-L., Uetake, J., Vallelonga, P., van de Wal, R. S. W., van der Wel, G., Vaughn, B. H., Vinther, B., Waddington, E., Wegner, Anna, Weikusat, Ilka, White, J. W. C., Wilhelms, Frank, Winstrup, M., Witrant, E., Wolff, E. W., Xiao, C., Zheng, J., Dahl-Jensen, D., Albert, M. R., Aldahan, A., Azuma, N., Balslev-Clausen, D., Baumgartner, M., Berggren, A.-M., Bigler, M., Binder, T., Blunier, T., Bourgeois, J. C., Brook, E. J., Buchardt, S. L., Buizert, C., Capron, E., Chappellaz, J., Chung, J., Clausen, H. B., Cvijanovic, I., Davies, S. M., Ditlevsen, P., Eicher, O., Fischer, H., Fisher, D. A., Fleet, L. G., Gfeller, G., Gkinis, V., Gogineni, S., Grinsted, A., Goto-Azuma, K., Gudlaugsdottir, H., Guillevic, M., Hansen, S. B., Hansson, M., Hirabayashi, M., Hong, S., Hur, S. D., Huybrechts, P., Hvidberg, C. S., Jenk, T., Iizuka, Y., Johnsen, S. J., Jones, T. R., Jouzel, J., Karlsson, N. B., Kawamura, K., Keegan, K., Kettner, E., Kipfstuhl, Sepp, Kjær, H. A., Koutnik, M., Kuramoto, T., Köhler, Peter, Laepple, Thomas, Landais, A., Langen, P. L., Larsen, L. B., Leuenberger, D., Leuenberger, M., Leuschen, C., Li, J., Lipenkov, V., Martinerie, P., Maselli, O. J., Masson-Delmotte, V., McConnell, J. R., Miller, Heinrich, Mini, O., Miyamoto, A., Montagnat-Rentier, M., Mulvaney, R., Muscheler, R., Paden, J., Orsi, A. J., Panton, C., Pattyn, F., Petit, J.-R., Pol, K., Popp, T., Possnert, G., Prié, F., Prokopiou, M., Quiquet, A., Rasmussen, S. O., Raynaud, D., Ren, J., Reutenauer, C., Ritz, C., Röckmann, T., Rosen, J. L., Rubino, M., Rybak, O., Samyn, D., Sapart, C. J., Schilt, A., Schmidt, A. M. Z., Schüpbach, S., Schwander, J., Seierstad, I., Severinghaus, J. P., Sheldon, S., Simonsen, S. B., Sjolte, J., Solgaard, A. M., Sowers, T., Sperlich, P., Steen-Larsen, H. C., Steffen, K., Steffensen, J. P., Steinhage, Daniel, Stocker, T. F., Stowasser, C., Sturevik, A. S., Sturges, W. T., Sveinbjörnsdottir, A., Svensson, A., Tison, J.-L., Uetake, J., Vallelonga, P., van de Wal, R. S. W., van der Wel, G., Vaughn, B. H., Vinther, B., Waddington, E., Wegner, Anna, Weikusat, Ilka, White, J. W. C., Wilhelms, Frank, Winstrup, M., Witrant, E., Wolff, E. W., Xiao, C., and Zheng, J.

Abstract

Efforts to extract a Greenland ice core with a complete record of the Eemian interglacial (130,000 to 115,000 years ago) have until now been unsuccessful. The response of the Greenland ice sheet to the warmer-than-present climate of the Eemian has thus remained unclear. Here we present the new North Greenland Eemian Ice Drilling (‘NEEM’) ice core and show only a modest ice-sheet response to the strong warming in the early Eemian. We reconstructed the Eemian record from folded ice using globally homogeneous parameters known from dated Greenland and Antarctic ice-core records. On the basis of water stable isotopes, NEEM surface temperatures after the onset of the Eemian (126,000 years ago) peaked at 8 ± 4 degrees Celsius above the mean of the past millennium, followed by a gradual cooling that was probably driven by the decreasing summer insolation. Between 128,000 and 122,000 years ago, the thickness of the northwest Greenland ice sheet decreased by 400 ± 250 metres, reaching surface elevations 122,000 years ago of 130 ± 300 metres lower than the present. Extensive surface melt occurred at the NEEM site during the Eemian, a phenomenon witnessed when melt layers formed again at NEEM during the exceptional heat of July 2012. With additional warming, surface melt might become more common in the future.

Published
2013

24. Eemian interglacial reconstructed from a Greenland folded ice core

Author

Dahl-Jensen, D., Albert, M. R., Aldahan, A., Azuma, N., Balslev-Clausen, D., Baumgartner, M., Berggren, A.-M., Bigler, M., Binder, T., Blunier, T., Bourgeois, J. C., Brook, E. J., Buchardt, S. L., Buizert, C., Capron, E., Chappellaz, J., Chung, J., Clausen, H. B., Cvijanovic, I., Davies, S. M., Ditlevsen, P., Eicher, O., Fischer, H., Fisher, D. A., Fleet, L. G., Gfeller, G., Gkinis, V., Gogineni, S., Grinsted, A., Goto-Azuma, K., Gudlaugsdottir, H., Guillevic, M., Hansen, S. B., Hansson, M., Hirabayashi, M., Hong, S., Hur, S. D., Huybrechts, P., Hvidberg, C. S., Jenk, T., Iizuka, Y., Johnsen, S. J., Jones, T. R., Jouzel, J., Karlsson, N. B., Kawamura, K., Keegan, K., Kettner, E., Kipfstuhl, Sepp, Kjær, H. A., Koutnik, M., Kuramoto, T., Köhler, Peter, Laepple, Thomas, Landais, A., Langen, P. L., Larsen, L. B., Leuenberger, D., Leuenberger, M., Leuschen, C., Li, J., Lipenkov, V., Martinerie, P., Maselli, O. J., Masson-Delmotte, V., McConnell, J. R., Miller, Heinrich, Mini, O., Miyamoto, A., Montagnat-Rentier, M., Mulvaney, R., Muscheler, R., Paden, J., Orsi, A. J., Panton, C., Pattyn, F., Petit, J.-R., Pol, K., Popp, T., Possnert, G., Prié, F., Prokopiou, M., Quiquet, A., Rasmussen, S. O., Raynaud, D., Ren, J., Reutenauer, C., Ritz, C., Röckmann, T., Rosen, J. L., Rubino, M., Rybak, O., Samyn, D., Sapart, C. J., Schilt, A., Schmidt, A. M. Z., Schüpbach, S., Schwander, J., Seierstad, I., Severinghaus, J. P., Sheldon, S., Simonsen, S. B., Sjolte, J., Solgaard, A. M., Sowers, T., Sperlich, P., Steen-Larsen, H. C., Steffen, K., Steffensen, J. P., Steinhage, Daniel, Stocker, T. F., Stowasser, C., Sturevik, A. S., Sturges, W. T., Sveinbjörnsdottir, A., Svensson, A., Tison, J.-L., Uetake, J., Vallelonga, P., van de Wal, R. S. W., van der Wel, G., Vaughn, B. H., Vinther, B., Waddington, E., Wegner, Anna, Weikusat, Ilka, White, J. W. C., Wilhelms, Frank, Winstrup, M., Witrant, E., Wolff, E. W., Xiao, C., Zheng, J., Dahl-Jensen, D., Albert, M. R., Aldahan, A., Azuma, N., Balslev-Clausen, D., Baumgartner, M., Berggren, A.-M., Bigler, M., Binder, T., Blunier, T., Bourgeois, J. C., Brook, E. J., Buchardt, S. L., Buizert, C., Capron, E., Chappellaz, J., Chung, J., Clausen, H. B., Cvijanovic, I., Davies, S. M., Ditlevsen, P., Eicher, O., Fischer, H., Fisher, D. A., Fleet, L. G., Gfeller, G., Gkinis, V., Gogineni, S., Grinsted, A., Goto-Azuma, K., Gudlaugsdottir, H., Guillevic, M., Hansen, S. B., Hansson, M., Hirabayashi, M., Hong, S., Hur, S. D., Huybrechts, P., Hvidberg, C. S., Jenk, T., Iizuka, Y., Johnsen, S. J., Jones, T. R., Jouzel, J., Karlsson, N. B., Kawamura, K., Keegan, K., Kettner, E., Kipfstuhl, Sepp, Kjær, H. A., Koutnik, M., Kuramoto, T., Köhler, Peter, Laepple, Thomas, Landais, A., Langen, P. L., Larsen, L. B., Leuenberger, D., Leuenberger, M., Leuschen, C., Li, J., Lipenkov, V., Martinerie, P., Maselli, O. J., Masson-Delmotte, V., McConnell, J. R., Miller, Heinrich, Mini, O., Miyamoto, A., Montagnat-Rentier, M., Mulvaney, R., Muscheler, R., Paden, J., Orsi, A. J., Panton, C., Pattyn, F., Petit, J.-R., Pol, K., Popp, T., Possnert, G., Prié, F., Prokopiou, M., Quiquet, A., Rasmussen, S. O., Raynaud, D., Ren, J., Reutenauer, C., Ritz, C., Röckmann, T., Rosen, J. L., Rubino, M., Rybak, O., Samyn, D., Sapart, C. J., Schilt, A., Schmidt, A. M. Z., Schüpbach, S., Schwander, J., Seierstad, I., Severinghaus, J. P., Sheldon, S., Simonsen, S. B., Sjolte, J., Solgaard, A. M., Sowers, T., Sperlich, P., Steen-Larsen, H. C., Steffen, K., Steffensen, J. P., Steinhage, Daniel, Stocker, T. F., Stowasser, C., Sturevik, A. S., Sturges, W. T., Sveinbjörnsdottir, A., Svensson, A., Tison, J.-L., Uetake, J., Vallelonga, P., van de Wal, R. S. W., van der Wel, G., Vaughn, B. H., Vinther, B., Waddington, E., Wegner, Anna, Weikusat, Ilka, White, J. W. C., Wilhelms, Frank, Winstrup, M., Witrant, E., Wolff, E. W., Xiao, C., and Zheng, J.

Abstract

Efforts to extract a Greenland ice core with a complete record of the Eemian interglacial (130,000 to 115,000 years ago) have until now been unsuccessful. The response of the Greenland ice sheet to the warmer-than-present climate of the Eemian has thus remained unclear. Here we present the new North Greenland Eemian Ice Drilling (‘NEEM’) ice core and show only a modest ice-sheet response to the strong warming in the early Eemian. We reconstructed the Eemian record from folded ice using globally homogeneous parameters known from dated Greenland and Antarctic ice-core records. On the basis of water stable isotopes, NEEM surface temperatures after the onset of the Eemian (126,000 years ago) peaked at 8 ± 4 degrees Celsius above the mean of the past millennium, followed by a gradual cooling that was probably driven by the decreasing summer insolation. Between 128,000 and 122,000 years ago, the thickness of the northwest Greenland ice sheet decreased by 400 ± 250 metres, reaching surface elevations 122,000 years ago of 130 ± 300 metres lower than the present. Extensive surface melt occurred at the NEEM site during the Eemian, a phenomenon witnessed when melt layers formed again at NEEM during the exceptional heat of July 2012. With additional warming, surface melt might become more common in the future.

Published
2013

25. Continuous monitoring of summer surface water vapour isotopic composition above the Greenland Ice Sheet

Author

Steen-Larsen, H. C., Johnsen, S. J., Masson-Delmotte, V., Stenni, B., Risi, C., Sodemann, H., Balslev-Clausen, D., Blunier, T., Dahl-Jensen, D., Ellehøj, M. D., Falourd, S., Gkinis, V., Grindsted, A., Jouzel, J., Popp, T., Sheldon, S., Simonsen, S. B., Sjolte, J., Steffensen, J. P., Sperlich, P., Sveinbjörnsdóttir, A. E., Vinther, B. M., White, J. W. C., Steen-Larsen, H. C., Johnsen, S. J., Masson-Delmotte, V., Stenni, B., Risi, C., Sodemann, H., Balslev-Clausen, D., Blunier, T., Dahl-Jensen, D., Ellehøj, M. D., Falourd, S., Gkinis, V., Grindsted, A., Jouzel, J., Popp, T., Sheldon, S., Simonsen, S. B., Sjolte, J., Steffensen, J. P., Sperlich, P., Sveinbjörnsdóttir, A. E., Vinther, B. M., and White, J. W. C.

Published
2013

26. Continuous monitoring of summer surface water vapour isotopic composition above the Greenland Ice Sheet

Author

Steen-Larsen, H. C., Johnsen, S. J., Masson-Delmotte, V., Stenni, B., Risi, C., Sodemann, H., Balslev-Clausen, D., Blunier, T., Dahl-Jensen, D., Ellehøj, M. D., Falourd, S., Gkinis, V., Grindsted, A., Jouzel, J., Popp, T., Sheldon, S., Simonsen, S. B., Sjolte, J., Steffensen, J. P., Sperlich, P., Sveinbjörnsdóttir, A. E., Vinther, B. M., White, J. W. C., Steen-Larsen, H. C., Johnsen, S. J., Masson-Delmotte, V., Stenni, B., Risi, C., Sodemann, H., Balslev-Clausen, D., Blunier, T., Dahl-Jensen, D., Ellehøj, M. D., Falourd, S., Gkinis, V., Grindsted, A., Jouzel, J., Popp, T., Sheldon, S., Simonsen, S. B., Sjolte, J., Steffensen, J. P., Sperlich, P., Sveinbjörnsdóttir, A. E., Vinther, B. M., and White, J. W. C.

Published
2013

27. Continuous monitoring of summer surface water vapour isotopic composition above the Greenland Ice Sheet

Author

Steen-Larsen, H. C., Johnsen, S. J., Masson-Delmotte, V., Stenni, B., Risi, C., Sodemann, H., Balslev-Clausen, D., Blunier, T., Dahl-Jensen, D., Ellehøj, M. D., Falourd, S., Gkinis, V., Grindsted, A., Jouzel, J., Popp, T., Sheldon, S., Simonsen, S. B., Sjolte, J., Steffensen, J. P., Sperlich, P., Sveinbjörnsdóttir, A. E., Vinther, B. M., White, J. W. C., Steen-Larsen, H. C., Johnsen, S. J., Masson-Delmotte, V., Stenni, B., Risi, C., Sodemann, H., Balslev-Clausen, D., Blunier, T., Dahl-Jensen, D., Ellehøj, M. D., Falourd, S., Gkinis, V., Grindsted, A., Jouzel, J., Popp, T., Sheldon, S., Simonsen, S. B., Sjolte, J., Steffensen, J. P., Sperlich, P., Sveinbjörnsdóttir, A. E., Vinther, B. M., and White, J. W. C.

Published
2013

28. Continuous monitoring of summer surface water vapour isotopic composition above the Greenland Ice Sheet

Author

Steen-Larsen, H. C., Johnsen, S. J., Masson-Delmotte, V., Stenni, B., Risi, C., Sodemann, H., Balslev-Clausen, D., Blunier, T., Dahl-Jensen, D., Ellehøj, M. D., Falourd, S., Gkinis, V., Grindsted, A., Jouzel, J., Popp, T., Sheldon, S., Simonsen, S. B., Sjolte, J., Steffensen, J. P., Sperlich, P., Sveinbjörnsdóttir, A. E., Vinther, B. M., White, J. W. C., Steen-Larsen, H. C., Johnsen, S. J., Masson-Delmotte, V., Stenni, B., Risi, C., Sodemann, H., Balslev-Clausen, D., Blunier, T., Dahl-Jensen, D., Ellehøj, M. D., Falourd, S., Gkinis, V., Grindsted, A., Jouzel, J., Popp, T., Sheldon, S., Simonsen, S. B., Sjolte, J., Steffensen, J. P., Sperlich, P., Sveinbjörnsdóttir, A. E., Vinther, B. M., and White, J. W. C.

Published
2013

33. Everolimus Prevents the Quilty Phenomenon – A Risk Factor for Microvasculopathy in Biopsy (RAD B253 Trial)

Author

UCL - SSS/IREC/CARD - Pôle de recherche cardiovasculaire, UCL - (SLuc) Service de chirurgie cardiovasculaire et thoracique, Hiemann, N.E., Bara, C., Segovia, J., Parameshwar, J., Simonsen, S., Crespo-Leiro, M., Eiskjaer, H., Vanhaecke, J., Arizon, J.M., Poncelet, Alain, Przybylowski, P., Frigerio, M., Lehmkuhl, H., Meyer, R., UCL - SSS/IREC/CARD - Pôle de recherche cardiovasculaire, UCL - (SLuc) Service de chirurgie cardiovasculaire et thoracique, Hiemann, N.E., Bara, C., Segovia, J., Parameshwar, J., Simonsen, S., Crespo-Leiro, M., Eiskjaer, H., Vanhaecke, J., Arizon, J.M., Poncelet, Alain, Przybylowski, P., Frigerio, M., Lehmkuhl, H., and Meyer, R.

Published
2011

34. Everolimus for the Prevention of Microvasculopathy in Biopsy: Final Results from Re-Evaluation of the RAD B253 Trial

Author

UCL - SSS/IREC/CARD - Pôle de recherche cardiovasculaire, UCL - (SLuc) Service de chirurgie cardiovasculaire et thoracique, Hiemann, N.E., Bara, C., Segovia, J., Parameshwar, J., Simonsen, S., Crespo-Leiro, M., Eiskjaer, H., Vanhaecke, J., Arizon, J.M., Poncelet, Alain, Przybylowski, P., Frigerio, M., Lehmkuhl, H., Meyer, R., UCL - SSS/IREC/CARD - Pôle de recherche cardiovasculaire, UCL - (SLuc) Service de chirurgie cardiovasculaire et thoracique, Hiemann, N.E., Bara, C., Segovia, J., Parameshwar, J., Simonsen, S., Crespo-Leiro, M., Eiskjaer, H., Vanhaecke, J., Arizon, J.M., Poncelet, Alain, Przybylowski, P., Frigerio, M., Lehmkuhl, H., and Meyer, R.

Published
2011

35. Validating firn compaction model with remote sensing data

Author

Simonsen, S. B., Stenseng, Lars, Sørensen, Louise Sandberg, Adalgeirsdottir, G., Hvidberg, C. S., Simonsen, S. B., Stenseng, Lars, Sørensen, Louise Sandberg, Adalgeirsdottir, G., and Hvidberg, C. S.

Abstract

A comprehensive understanding of firn processes is of outmost importance, when estimating present and future changes of the Greenland Ice Sheet. Especially, when remote sensing altimetry is used to assess the state of ice sheets and their contribution to global sea level rise, firn compaction models have been shown to be a key component. Now, remote sensing data can also be used to validate the firn models. Radar penetrating the upper part of the firn column in the interior part of Greenland shows a clear layering. The observed layers from the radar data can be used as an in-situ validation of firn models over large length scales. Here, a simple empirical firn model that is forced with the output of high-resolution (5km) regional climate model (HIRHAM5) is explored. The model is capable of describing a layered structure of the firn column and has previously been used to estimate changes of firn compaction to correct ICESat measurements and assessing the present mass loss of the Greenland ice sheet. Validation of the model against the radar data gives good results and confidence in using the model to answer important questions. Questions such as; how large is the firn compaction correction relative to the changes in the elevation of the surface observed with remote sensing altimetry? What model time resolution is necessary to resolved the observed layering? What model refinements are necessary to give better estimates of the surface mass balance of the Greenland ice sheet from remote sensing altimetry?

Published
2011

36. Validating firn compaction model with remote sensing data

Author

Simonsen, S. B., Stenseng, Lars, Sørensen, Louise Sandberg, Adalgeirsdottir, G., Hvidberg, C. S., Simonsen, S. B., Stenseng, Lars, Sørensen, Louise Sandberg, Adalgeirsdottir, G., and Hvidberg, C. S.

Abstract

A comprehensive understanding of firn processes is of outmost importance, when estimating present and future changes of the Greenland Ice Sheet. Especially, when remote sensing altimetry is used to assess the state of ice sheets and their contribution to global sea level rise, firn compaction models have been shown to be a key component. Now, remote sensing data can also be used to validate the firn models. Radar penetrating the upper part of the firn column in the interior part of Greenland shows a clear layering. The observed layers from the radar data can be used as an in-situ validation of firn models over large length scales. Here, a simple empirical firn model that is forced with the output of high-resolution (5km) regional climate model (HIRHAM5) is explored. The model is capable of describing a layered structure of the firn column and has previously been used to estimate changes of firn compaction to correct ICESat measurements and assessing the present mass loss of the Greenland ice sheet. Validation of the model against the radar data gives good results and confidence in using the model to answer important questions. Questions such as; how large is the firn compaction correction relative to the changes in the elevation of the surface observed with remote sensing altimetry? What model time resolution is necessary to resolved the observed layering? What model refinements are necessary to give better estimates of the surface mass balance of the Greenland ice sheet from remote sensing altimetry?

Published
2011

37. Everolimus Introduction and Calcineurin Reduction in Thoracic Transplant Recipients with Advanced Chronic Renal Failure in JOURNAL OF HEART AND LUNG TRANSPLANTATION, vol 30, issue 4, pp S25-S25

Author

Arora, S, Rundqvist, B, Mortensen, S-A, Eiskjaer, H, Riise, G, Mared, L, Bjortuft, O, Ekmehag, B, Jansson, Kjell, Simonsen, S, Gude, E, Solbu, D, Iversen, M, Gullestad, L, Arora, S, Rundqvist, B, Mortensen, S-A, Eiskjaer, H, Riise, G, Mared, L, Bjortuft, O, Ekmehag, B, Jansson, Kjell, Simonsen, S, Gude, E, Solbu, D, Iversen, M, and Gullestad, L

Abstract

n/a

Published
2011

38. Effect of Everolimus Introduction and Calcineurin Inhibitor Reduction on Cardiac Allograft Vasculopathy Assessed by Virtual Histology in JOURNAL OF HEART AND LUNG TRANSPLANTATION, vol 30, issue 4, pp S33-S34

Author

Arora, S, Erikstad, I, Wennerblom, B, Sigurdardottir, V, Eiskjaer, H, Botker, H, A Mortensen, S, Saunameki, K, Ekmehag, B, Jansson, Kjell, Simonsen, S, Gude, E, Ragnarsson, A, Solbu, D, Gullestad, L, Arora, S, Erikstad, I, Wennerblom, B, Sigurdardottir, V, Eiskjaer, H, Botker, H, A Mortensen, S, Saunameki, K, Ekmehag, B, Jansson, Kjell, Simonsen, S, Gude, E, Ragnarsson, A, Solbu, D, and Gullestad, L

Abstract

n/a

Published
2011

39. Everolimus for the Prevention of Microvasculopathy in Biopsy in Cardiac Transplant Recipients: Preliminary Results from Re-Evaluation of the RAD B253 Trial

Author

UCL - (SLuc) Service de chirurgie cardiovasculaire et thoracique, UCL - SSS/IREC/CARD - Pôle de recherche cardiovasculaire, Hiemann, N. E., Bara, C., Segovia, J., Simonsen, S., Crespo-Leiro, M., Eiskjaer, H., Vanhaecke, Johan, Poncelet, Alain, Przybylowski, P., Frigerio, M., Lehmkuhl, H. B., Meyer, R., UCL - (SLuc) Service de chirurgie cardiovasculaire et thoracique, UCL - SSS/IREC/CARD - Pôle de recherche cardiovasculaire, Hiemann, N. E., Bara, C., Segovia, J., Simonsen, S., Crespo-Leiro, M., Eiskjaer, H., Vanhaecke, Johan, Poncelet, Alain, Przybylowski, P., Frigerio, M., Lehmkuhl, H. B., and Meyer, R.

Published
2010

42. Everolimus Introduction with CNI Minimization Significantly Improves Renal Function in Thoracic Transplant Recipients: A Scandinavian Multicenter, Randomized Study in JOURNAL OF HEART AND LUNG TRANSPLANTATION, vol 29, issue 2, pp S49-S49

Author

Gullestad, L, Rundqvist, B, A Mortensen, S, Eiskjaer, H, C Riise, G, Mared, L, Bjortuft, O, Ekmehag, B, Jansson, Kjell, Simonsen, S, Gude, E, Fagertun, H, Solbu, D, Iversen, M, Gullestad, L, Rundqvist, B, A Mortensen, S, Eiskjaer, H, C Riise, G, Mared, L, Bjortuft, O, Ekmehag, B, Jansson, Kjell, Simonsen, S, Gude, E, Fagertun, H, Solbu, D, and Iversen, M

Abstract

n/a

Published
2010

43. Effect of Everolimus Introduction and Calcineurin Inhibitor Reduction on Graft Vasculopathy in Heart Transplant Recipients in JOURNAL OF HEART AND LUNG TRANSPLANTATION, vol 29, issue 2, pp S50-S50

Author

Arora, S, Wennerblom, B, Rundqvist, B, Eiskjaer, H, E Botker, H, Mortensen, S-A, Saunameki, K, Ekmehag, B, Jansson, Kjell, Simonsen, S, Gude, E, Endresen, K, Solbu, D, Gullestad, L, Arora, S, Wennerblom, B, Rundqvist, B, Eiskjaer, H, E Botker, H, Mortensen, S-A, Saunameki, K, Ekmehag, B, Jansson, Kjell, Simonsen, S, Gude, E, Endresen, K, Solbu, D, and Gullestad, L

Abstract

n/a

Published
2010

46. Carbonatite melt-CO2 fluid inclusions in mantle xenoliths from Tenerife, Canary Islands: a story of trapping, immiscibility and fluid-rock interaction in the upper mantle

Author

Frezzotti, M, Andersen, T, Neumann, E, Simonsen, S, Neumann, Er, Simonsen, Sl, Frezzotti, M, Andersen, T, Neumann, E, Simonsen, S, Neumann, Er, and Simonsen, Sl

Abstract

Three types of fluid inclusions have been identified in olivine porphyroclasts in the spinel harzburgite and lherzolite xenoliths from Tenerife: pure CO2 (Type A); carbonate-rich CO2-SO2 mixtures (Type B); and polyphase inclusions dominated by silicate glass +/- fluid +/- sp +/- silicate +/- sulfide +/- carbonate (Type C). Type A inclusions commonly exhibit a "coating" (a few microns thick) consisting of an aggregate of a platy, hydrous Mg-Fe-Si phase, most likely tale, together with very small amounts of halite, dolomite and other phases. Larger crystals (e.g. (Na,K)Cl, dolomite, spinel, sulfide and phlogopite) may be found on either side of the "coating", towards the wall of the host mineral or towards the inclusion center. These different fluids were formed through the immiscible separations and fluid-wall-rock reactions from a common, volatile-rich, siliceous, alkaline carbonatite melt infiltrating the upper mantle beneath the Tenerife. First, the original siliceous carbonatite melt is separated from a mixed CO2-H2O-NaCl fluid and a silicate/silicocarbonatite melt (preserved in Type A inclusions). The reaction of the carbonaceous silicate melt with the wall-rock minerals gave rise to large poikilitic orthopyroxene and clinopyroxene grains, and smaller neoblasts. During the metasomatic processes, the consumption of the silicate part of the melt produced carbonate-enriched Type B CO2-SO2 fluids which were trapped in exsolved orthopyroxene porphyroclasts. At the later stages, the interstitial silicate/silicocarbonatite fluids were trapped as Type C inclusions. At a temperature above 650 degreesC, the mixed CO2-H2O-NaCl fluid inside the Type A inclusions were separated into CO2-rich fluid and H2O-NaCl brine. At T<650 degreesC, the residual silicate melt reacted with the host olivine, forming a reaction rim or "coating" along the inclusion walls consisting of talc (or possibly serpentine) together with minute crystals of NaCl, KCl, carbonates and sulfides, leaving a

Published
2002

47. Mid-Proterozoic crustal recycling and rare element deposits in the Gardar province, S. Greenland.

Author

Finch A.A., Andersen T., Borst A.M., Horsburgh N.J., Hutchison W., Simonsen S., Finch A.A., Andersen T., Borst A.M., Horsburgh N.J., Hutchison W., and Simonsen S.

Abstract

Lu-Hf isotope values from several early and late centres across the Mesoproterozoic Gardar province are consistent with a model that suggests recycling of Archaean crust via the mantle in the Gardar period of alkaline magmatism from intraplate rifting, helping to explain the significant numbers of rare element deposits formed in Garda times. Such processes may have been important in providing the conditions for rare element deposit formation throughout geological time., Lu-Hf isotope values from several early and late centres across the Mesoproterozoic Gardar province are consistent with a model that suggests recycling of Archaean crust via the mantle in the Gardar period of alkaline magmatism from intraplate rifting, helping to explain the significant numbers of rare element deposits formed in Garda times. Such processes may have been important in providing the conditions for rare element deposit formation throughout geological time.

48. Mass balance of the Antarctic Ice Sheet from 1992 to 2017

Author

Shepherd, A., Ivins, E., Rignot, E., Smith, B., van den Broeke, M., Velicogna, I., Whitehouse, P., Briggs, K., Joughin, I., Krinner, G., Nowicki, S., Payne, T., Scambos, T., Schlegel, N., Geruo, A., Agosta, C., Ahlstrom, A., Bobonis, G., Barletta, v., Blazquez, A., Bonin, J., Csatho, B., Cullather, R., Felikson, D., Fettweis, X., Forsberg, R., Gallee, H., Gardner, A., Gilbert, L., Groh, A., Gunter, B., Hanna, Edward, Harig, C., Helm, V., Horvath, A., Horwath, M., Khan, S., Kjeldsen, K.K., Konrad, H., Langen, P., Lecavalier, B., Loomis, B., Luthcke, S., McMillan, M., Melini, D., Mernild, S., Mohajerani, Y., Moore, P., Mouginot, J., Moyano, G., Muir, A., Nagler, T., Nield, G., Nilsson, J., Noel, B., Otosaka, I., Pattle, M.E., Peltier, W.R., Pie, N., Bietbroek, R., Rott, H., Sandberg-Sorensen, L., Sasgen, I., Save, H., Scheuchl, B., Schrama, E., Schroder, L., Seo, K.-W., Simonsen, S., Slater, T., Spada, G., Sutterley, T., Talpe, M., Tarasov, L., van de Berg, W., van der Wal, W., van Wessem, M., Vishwakarma, B., Wiese, D., Wouters, B., Shepherd, A., Ivins, E., Rignot, E., Smith, B., van den Broeke, M., Velicogna, I., Whitehouse, P., Briggs, K., Joughin, I., Krinner, G., Nowicki, S., Payne, T., Scambos, T., Schlegel, N., Geruo, A., Agosta, C., Ahlstrom, A., Bobonis, G., Barletta, v., Blazquez, A., Bonin, J., Csatho, B., Cullather, R., Felikson, D., Fettweis, X., Forsberg, R., Gallee, H., Gardner, A., Gilbert, L., Groh, A., Gunter, B., Hanna, Edward, Harig, C., Helm, V., Horvath, A., Horwath, M., Khan, S., Kjeldsen, K.K., Konrad, H., Langen, P., Lecavalier, B., Loomis, B., Luthcke, S., McMillan, M., Melini, D., Mernild, S., Mohajerani, Y., Moore, P., Mouginot, J., Moyano, G., Muir, A., Nagler, T., Nield, G., Nilsson, J., Noel, B., Otosaka, I., Pattle, M.E., Peltier, W.R., Pie, N., Bietbroek, R., Rott, H., Sandberg-Sorensen, L., Sasgen, I., Save, H., Scheuchl, B., Schrama, E., Schroder, L., Seo, K.-W., Simonsen, S., Slater, T., Spada, G., Sutterley, T., Talpe, M., Tarasov, L., van de Berg, W., van der Wal, W., van Wessem, M., Vishwakarma, B., Wiese, D., and Wouters, B.

Abstract

The Antarctic Ice Sheet is an important indicator of climate change and driver of sea-level rise. Here we combine satellite observations of its changing volume, flow and gravitational attraction with modelling of its surface mass balance to show that it lost 2,720 ± 1,390 billion tonnes of ice between 1992 and 2017, which corresponds to an increase in mean sea level of 7.6 ± 3.9 millimetres (errors are one standard deviation). Over this period, ocean-driven melting has caused rates of ice loss from West Antarctica to increase from 53 ± 29 billion to 159 ± 26 billion tonnes per year; ice-shelf collapse has increased the rate of ice loss from the Antarctic Peninsula from 7 ± 13 billion to 33 ± 16 billion tonnes per year. We find large variations in and among model estimates of surface mass balance and glacial isostatic adjustment for East Antarctica, with its average rate of mass gain over the period 1992–2017 (5 ± 46 billion tonnes per year) being the least certain.

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