caa a22 4500 605474796 CHVBK 20210128100349.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s00382-014-2356-5 doi (NATIONALLICENCE)springer-10.1007/s00382-014-2356-5 Effect of snow cover on pan-Arctic permafrost thermal regimes [Elektronische Daten] [Hotaek Park, Alexander Fedorov, Mikhail Zheleznyak, Pavel Konstantinov, John Walsh] This study quantitatively evaluated how insulation by snow depth (SND) affected the soil thermal regime and permafrost degradation in the pan-Arctic area, and more generally defined the characteristics of soil temperature (TSOIL) and SND from 1901 to 2009. This was achieved through experiments performed with the land surface model CHANGE to assess sensitivity to winter precipitation as well as air temperature. Simulated TSOIL, active layer thickness (ALT), SND, and snow density were generally comparable with in situ or satellite observations at large scales and over long periods. Northernmost regions had snow that remained relatively stable and in a thicker state during the past four decades, generating greater increases in TSOIL. Changes in snow cover have led to changes in the thermal state of the underlying soil, which is strongly dependent on both the magnitude and the timing of changes in snowfall. Simulations of the period 2001-2009 revealed significant differences in the extent of near-surface permafrost, reflecting differences in the model's treatment of meteorology and the soil bottom boundary. Permafrost loss was greater when SND increased in autumn rather than in winter, due to insulation of the soil resulting from early cooling. Simulations revealed that TSOIL tended to increase over most of the pan-Arctic from 1901 to 2009, and that this increase was significant in northern regions, especially in northeastern Siberia where SND is responsible for 50% or more of the changes in TSOIL at a depth of 3.6m. In the same region, ALT also increased at a rate of approximately 2.3cm per decade. The most sensitive response of ALT to changes in SND appeared in the southern boundary regions of permafrost, in contrast to permafrost temperatures within the 60°N-80°N region, which were more sensitive to changes in snow cover. Finally, our model suggests that snow cover contributes to the warming of permafrost in northern regions and could play a more important role under conditions of future Arctic warming. Springer-Verlag Berlin Heidelberg, 2014 Active layer thickness nationallicence Arctic climate nationallicence Land surface model nationallicence Permafrost extent nationallicence Snow depth nationallicence Soil temperature nationallicence Park Hotaek Research and Development Center for Global Change, JAMSTEC, Yokosuka, Japan aut Fedorov Alexander Melnikov Permafrost Institute, SB RAS, Yakutsk, Russia aut Zheleznyak Mikhail Melnikov Permafrost Institute, SB RAS, Yakutsk, Russia aut Konstantinov Pavel Melnikov Permafrost Institute, SB RAS, Yakutsk, Russia aut Walsh John International Arctic Research Center, University of Alaska Fairbanks, 99775, Fairbanks, AK, USA aut Climate Dynamics Springer Berlin Heidelberg 44/9-10(2015-05-01), 2873-2895 0930-7575 44:9-10<2873 2015 44 382 https://doi.org/10.1007/s00382-014-2356-5 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00382-014-2356-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Park Hotaek Research and Development Center for Global Change, JAMSTEC, Yokosuka, Japan aut NATIONALLICENCE 700 1- Fedorov Alexander Melnikov Permafrost Institute, SB RAS, Yakutsk, Russia aut NATIONALLICENCE 700 1- Zheleznyak Mikhail Melnikov Permafrost Institute, SB RAS, Yakutsk, Russia aut NATIONALLICENCE 700 1- Konstantinov Pavel Melnikov Permafrost Institute, SB RAS, Yakutsk, Russia aut NATIONALLICENCE 700 1- Walsh John International Arctic Research Center, University of Alaska Fairbanks, 99775, Fairbanks, AK, USA aut NATIONALLICENCE 773 0- Climate Dynamics Springer Berlin Heidelberg 44/9-10(2015-05-01), 2873-2895 0930-7575 44:9-10<2873 2015 44 382