Chinese Journal of Polar Research

Chinese Journal of Polar Research ›› 2024, Vol. 36 ›› Issue (4): 591-607.DOI: 10.13679/j.jdyj.20230019

Previous Articles     Next Articles

Analysis of the surface mass balance over the Greenland ice sheet based on regional climate model RACMO2.3

HUAI Baojuan1, DING Minghu2, ZHANG Qinglin1, SUN Weijun1, ZHANG Wuying1,CHE Jiahang1, KANG Limin1#br#   

  1. 1 College of Geography and Environment, Shandong Normal University, Jinan 250358, China; 
    2 State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081, China
  • Received:2023-04-17 Revised:2023-05-28 Online:2024-12-31 Published:2025-01-15
  • Contact: Ming-Hu DING

PDF (PC)

110

Abstract: The Greenland ice sheet (GrIS) change consists of discharge and surface mass balance (SMB), and SMB is the net of mass income and expenditure at the ice sheet surface, dominating recent GrIS mass loss. In this study, we analyzed the detailed change of SMB and its components over the GrIS from 1958 to 2022, using monthly SMB data (1 km) from regional climate model RACMO2.3 p2 developed by the Royal Netherlands Meteorological Institute. The results show that (1) the multi-year average SMB integrated by the GrIS is 366.8 Gt·a–1, with obvious regional SMB differences. The central part of the edge of the west GrIS is the main strong ablation area (SMB<-1600 mm w.e.·a–1). The high precipitation characteristics of the southeast GrIS lead to high mass accumulation in the accumulation area, especially in the edge of the ice sheet with SMB over 3200 mm w.e.·a–1; (2) Seasonally, the summer SMB is dominated by negative balance at the ice sheet scale, and precipitation accumulation in winter shows a decreasing pattern from coastal to inland and from south to north; The main melt season starts in May and peaks in July (SMB=-123.8 Gt); (3) The interannual variations of net SMB over the GrIS was large during 1958 to 2022. The precipitation dominated the SMB changes before the 1990s. There was a significant negative trend (-48.7 Gt·(10 a)–2, p<0.05) post-1990, caused by the increase of runoff; (4) Spatially, there is a generally negative trend in SMB in the ice sheet melt zone during the study period (<-80 mm w.e.·(10 a)–2, p<0.05), due to increased surface melt and reduced refreezing. The SMB change in the southeast GrIS was forced by precipitation change. The SMB over the GrIS is significantly influenced by large-scale circulation anomalies, radiation, albedo, and ocean. Under the background of future warming, the negative trend of SMB on the GrIS will be more significant, which will induce sea level rise and should be paid more attention to. 

Key words: Greenland Ice sheet, Surface mass balance, Regional climate model, RACMO2.3