Modelling the regional climate and isotopic composition of Svalbard precipitation using REMOiso: a comparison with available GNIP and ice core data |
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| Authors: | D V Divine J Sjolte E Isaksson H A J Meijer R S W van de Wal T Martma V Pohjola C Sturm F Godtliebsen |
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| Institution: | 1. Department of Mathematics and Statistics, University of Troms?, Troms?, Norway;2. Norwegian Polar Institute, Polar Environmental Centre, Troms?, Norway;3. Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Denmark;4. Centre for Isotope Research, Groningen, The Netherlands;5. Institute for Marine and Atmospheric Research Utrecht, Utrecht University, The Netherlands;6. Institute of Geology, Tallinn University of Technology, Tallinn, Estonia;7. Department of Earth Sciences, Uppsala University, Uppsala, Sweden;8. Department of Geology and Geochemistry, Stockholm University, Stockholm, Sweden |
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| Abstract: | Simulations of a regional (approx. 50 km resolution) circulation model REMOiso with embedded stable water isotope module covering the period 1958‐2001 are compared with the two instrumental climate and four isotope series (δ18O) from western Svalbard. We examine the data from ice cores drilled on Svalbard ice caps in 1997 (Lomonosovfonna, 1250 m asl) and 2005 (Holtedahlfonna, 1150 m asl) and the GNIP series from Ny‐Ålesund and Isfjord Radio. The surface air temperature (SAT) and precipitation data from Longyearbyen and Ny‐Ålesund are used to assess the skill of the model in reproducing the local climate. The model successfully captures the climate variations on the daily to multidecadal times scales although it tends to systematically underestimate the winter SAT. Analysis suggests that REMOiso performs better at simulating isotope compositions of precipitation in the winter than summer. The simulated and measured Holtedahlfonna δ18O series agree reasonably well, whereas no significant correlation has been observed between the modelled and measured Lomonosovfonna ice core isotopic series. It is shown that sporadic nature as well as variability in the amount inherent in precipitation process potentially limits the accuracy of the past SAT reconstruction from the ice core data. This effect in the study area is, however, diminished by the role of other factors controlling δ18O in precipitation, most likely sea ice extent, which is directly related with the SAT anomalies. Copyright © 2011 John Wiley & Sons, Ltd. |
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| Keywords: | regional modelling stable water isotopes forward proxy modelling Svalbard climate ice cores |
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