DOI: 10.5194/tc-14-1809-2020
论文题名: The added value of high resolution in estimating the surface mass balance in southern Greenland
作者: Jan Van De Berg W. ; Van Meijgaard E. ; Van Ulft L.H.
刊名: Cryosphere
ISSN: 19940416
出版年: 2020
卷: 14, 期: 6 起始页码: 1809
结束页码: 1827
语种: 英语
英文关键词: climate modeling
; estimation method
; mass balance
; precipitation (climatology)
; regional climate
; Arctic
; Arctic Ocean
; Greenland
; Greenland Ice Sheet
; Greenland Sea
; Norwegian Sea
英文摘要: The polar version of the regional climate model RACMO2, version 2.3p1, is used to study the effect of model resolution on the simulated climate and surface mass balance (SMB) of south Greenland for the current climate (2007-2014). The model data at resolutions of 60, 20, 6.6, and 2.2 span classCombining double low line"inline-formula"km/span are intercompared and compared to SMB observations using three different data refinement methods: nearest neighbour, bilinear interpolation, and a statistical downscaling method utilising the local dependency of fields on elevation. Furthermore, it is estimated how the errors induced by model resolution compare to errors induced by the model physics and initialisation./p pThe results affirm earlier studies that SMB components which are tightly linked to elevation, like runoff, can be refined successfully, as soon as the ablation zone is reasonably well resolved in the source dataset. Precipitation fields are also highly elevation dependent, but precipitation has no systematic correlation with elevation, which inhibits statistical downscaling to work well. If refined component-wise, 20 span classCombining double low line"inline-formula"km/span resolution model simulations can reproduce the SMB ablation observations almost as well as the finer-resolution model simulations. Nonetheless, statistical downscaling and regional climate modelling are complementary; the best results are obtained when high-resolution RACMO2 data are statistically refined. Model estimates in the accumulation zone do not benefit from statistical downscaling; hence, a resolution of about 20 span classCombining double low line"inline-formula"km/span is sufficient to resolve the majority of the accumulation zone of the Greenland Ice Sheet with respect to the limited measurements we have./p pFurthermore, we demonstrate that using RACMO2, a hydrostatic model, at 2.2 span classCombining double low line"inline-formula"km/span resolution led to invalid results as topographic and synoptic vertical winds exceed 10 span classCombining double low line"inline-formula"m s-1/span, which violates the hydrostatic model assumptions./p pFinally, additional tests show that model resolution is as important as properly resolving spatial albedo patterns, correctly initialising the firn column, and uncertainties in the modelled precipitation and turbulent exchange. © Author(s) 2020. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164491
Appears in Collections: 气候变化与战略
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作者单位: IMAU, Utrecht University, Utrecht, Netherlands; KNMI, De Bilt, Netherlands
Recommended Citation:
Jan Van De Berg W.,Van Meijgaard E.,Van Ulft L.H.. The added value of high resolution in estimating the surface mass balance in southern Greenland[J]. Cryosphere,2020-01-01,14(6)