G. Gastineau, C. Frankignoul, Yongqi Gao, Yu‐Chiao Liang, Young‐Oh Kwon, A. Cherchi, R. Ghosh, E. Manzini, D. Matei, J. Mecking, L. Suo, T. Tian, Shuting Yang, Ying Zhang
{"title":"Forcing and impact of the Northern Hemisphere continental snow cover in 1979–2014","authors":"G. Gastineau, C. Frankignoul, Yongqi Gao, Yu‐Chiao Liang, Young‐Oh Kwon, A. Cherchi, R. Ghosh, E. Manzini, D. Matei, J. Mecking, L. Suo, T. Tian, Shuting Yang, Ying Zhang","doi":"10.5194/tc-17-2157-2023","DOIUrl":null,"url":null,"abstract":"Abstract. The main drivers of the continental Northern Hemisphere snow cover are investigated in the 1979–2014 period. Four observational datasets are used\nas are two large multi-model ensembles of atmosphere-only simulations with prescribed sea surface temperature (SST) and sea ice concentration (SIC). A\nfirst ensemble uses observed interannually varying SST and SIC conditions for 1979–2014, while a second ensemble is identical except for SIC with\na repeated climatological cycle used. SST and external forcing typically explain 10 % to 25 % of the snow cover variance in model\nsimulations, with a dominant forcing from the tropical and North Pacific SST during this period. In terms of the climate influence of the snow cover\nanomalies, both observations and models show no robust links between the November and April snow cover variability and the atmospheric circulation\n1 month later. On the other hand, the first mode of Eurasian snow cover variability in January, with more extended snow over western Eurasia, is\nfound to precede an atmospheric circulation pattern by 1 month, similar to a negative Arctic oscillation (AO). A decomposition of the variability\nin the model simulations shows that this relationship is mainly due to internal climate variability. Detailed outputs from one of the models\nindicate that the western Eurasia snow cover anomalies are preceded by a negative AO phase accompanied by a Ural blocking pattern and a\nstratospheric polar vortex weakening. The link between the AO and the snow cover variability is strongly related to the concomitant role of the\nstratospheric polar vortex, with the Eurasian snow cover acting as a positive feedback for the AO variability in winter. No robust influence of the\nSIC variability is found, as the sea ice loss in these simulations only drives an insignificant fraction of the snow cover anomalies, with few\nagreements among models.\n","PeriodicalId":56315,"journal":{"name":"Cryosphere","volume":" ","pages":""},"PeriodicalIF":4.4000,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cryosphere","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.5194/tc-17-2157-2023","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOGRAPHY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Abstract. The main drivers of the continental Northern Hemisphere snow cover are investigated in the 1979–2014 period. Four observational datasets are used
as are two large multi-model ensembles of atmosphere-only simulations with prescribed sea surface temperature (SST) and sea ice concentration (SIC). A
first ensemble uses observed interannually varying SST and SIC conditions for 1979–2014, while a second ensemble is identical except for SIC with
a repeated climatological cycle used. SST and external forcing typically explain 10 % to 25 % of the snow cover variance in model
simulations, with a dominant forcing from the tropical and North Pacific SST during this period. In terms of the climate influence of the snow cover
anomalies, both observations and models show no robust links between the November and April snow cover variability and the atmospheric circulation
1 month later. On the other hand, the first mode of Eurasian snow cover variability in January, with more extended snow over western Eurasia, is
found to precede an atmospheric circulation pattern by 1 month, similar to a negative Arctic oscillation (AO). A decomposition of the variability
in the model simulations shows that this relationship is mainly due to internal climate variability. Detailed outputs from one of the models
indicate that the western Eurasia snow cover anomalies are preceded by a negative AO phase accompanied by a Ural blocking pattern and a
stratospheric polar vortex weakening. The link between the AO and the snow cover variability is strongly related to the concomitant role of the
stratospheric polar vortex, with the Eurasian snow cover acting as a positive feedback for the AO variability in winter. No robust influence of the
SIC variability is found, as the sea ice loss in these simulations only drives an insignificant fraction of the snow cover anomalies, with few
agreements among models.
期刊介绍:
The Cryosphere (TC) is a not-for-profit international scientific journal dedicated to the publication and discussion of research articles, short communications, and review papers on all aspects of frozen water and ground on Earth and on other planetary bodies.
The main subject areas are the following:
ice sheets and glaciers;
planetary ice bodies;
permafrost and seasonally frozen ground;
seasonal snow cover;
sea ice;
river and lake ice;
remote sensing, numerical modelling, in situ and laboratory studies of the above and including studies of the interaction of the cryosphere with the rest of the climate system.