DOI: 10.5194/tc-9-2383-2015
Scopus记录号: 2-s2.0-84951868137
论文题名: Summertime evolution of snow specific surface area close to the surface on the Antarctic Plateau
作者: Libois Q ; , Picard G ; , Arnaud L ; , Dumont M ; , Lafaysse M ; , Morin S ; , Lefebvre E
刊名: Cryosphere
ISSN: 19940416
出版年: 2015
卷: 9, 期: 6 起始页码: 2383
结束页码: 2398
语种: 英语
英文关键词: absorption
; air temperature
; annual variation
; crystal
; energy budget
; ice sheet
; metamorphism
; parameterization
; satellite data
; snow cover
; snowpack
; solar radiation
; summer
; surface area
; wind field
; Antarctic Plateau
; Antarctica
; East Antarctica
; Crocus
英文摘要: On the Antarctic Plateau, snow specific surface area (SSA) close to the surface shows complex variations at daily to seasonal scales which affect the surface albedo and in turn the surface energy budget of the ice sheet. While snow metamorphism, precipitation and strong wind events are known to drive SSA variations, usually in opposite ways, their relative contributions remain unclear. Here, a comprehensive set of SSA observations at Dome C is analysed with respect to meteorological conditions to assess the respective roles of these factors. The results show an average 2-to-3-fold SSA decrease from October to February in the topmost 10 cm in response to the increase of air temperature and absorption of solar radiation in the snowpack during spring and summer. Surface SSA is also characterized by significant daily to weekly variations due to the deposition of small crystals with SSA up to 100 m2 kg-1 onto the surface during snowfall and blowing snow events. To complement these field observations, the detailed snowpack model Crocus is used to simulate SSA, with the intent to further investigate the previously found correlation between interannual variability of summer SSA decrease and summer precipitation amount. To this end, some Crocus parameterizations have been adapted to Dome C conditions, and the model was forced by ERA-Interim reanalysis. It successfully matches the observations at daily to seasonal timescales, except for the few cases when snowfalls are not captured by the reanalysis. On the contrary, the interannual variability of summer SSA decrease is poorly simulated when compared to 14 years of microwave satellite data sensitive to the near-surface SSA. A simulation with disabled summer precipitation confirms the weak influence in the model of the precipitation on metamorphism, with only 6 % enhancement. However, we found that disabling strong wind events in the model is sufficient to reconciliate the simulations with the observations. This suggests that Crocus reproduces well the contributions of metamorphism and precipitation on surface SSA, but snow compaction by the wind might be overestimated in the model. © Author(s) 2015. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75210
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: Univ. Grenoble Alpes, LGGE (UMR5183), Grenoble, France; CNRS, LGGE (UMR5183), Grenoble, France; Météo-France - CNRS, CNRM - GAME (UMR 3589), Centre d'Études de la Neige, Grenoble, France; ESCER Centre, Department of Earth and Atmospheric Sciences, Université du Québec À Montréal, 201 Av. du Président-Kennedy, Montréal, Canada
Recommended Citation:
Libois Q,, Picard G,, Arnaud L,et al. Summertime evolution of snow specific surface area close to the surface on the Antarctic Plateau[J]. Cryosphere,2015-01-01,9(6)