格陵兰冰盖物质平衡由其触地线处冰通量和表面物质平衡组成，表面物质平衡是冰盖表面物质收入和支出的净值，在近期格陵兰冰盖物质损失中占主导地位。本文基于荷兰皇家气象研究院开发的1 km区域气候模式RACMO2。3 p2 日表面物质平衡数据，对1958-2022年格陵兰冰盖的表面物质平衡及其组分做了详细分析。结果表明，(1)格陵兰冰盖多年平均表面物质平衡为366。8 Gt·a-1，表面物质平衡区域差异明显，冰盖西侧中部为主要强消融区域(表面物质平衡<-1600 mm w。e。·a-1)，冰盖东南部的高降水特征导致此处积累区表现为高物质累积态，积累区下部年表面物质平衡超过3200 mm w。e。·a-1;(2)季节上，格陵兰冰盖表面物质平衡在冰盖尺度上夏季以负平衡为主，冬季以降水积累为主，呈现从沿海到内陆、从南到北递减的格局;其主要消融季从5月开始，7月达到顶峰(表面物质平衡为-123。8 Gt);(3)近60年来格陵兰冰盖表面物质平衡年际变化大，整体上，20世纪90年代之前，降水主导了表面物质平衡变化，20世纪90年代后，表面物质平衡的显著负趋势(-48。7 Gt·(10 a)-2，p<0。05)则由融水径流的快速增加所致;(4)空间上，由表面消融增加和再冻结能力下降导致的冰盖消融区普遍呈现负趋势(<-80 mm w。e。·(10 a)-2，p<0。05)，冰盖东南部的表面物质平衡变化主要受降水变化驱动。格陵兰冰盖表面物质平衡受大气环流异常、辐射、反照率、海洋等因素影响，未来变暖背景下，冰盖表面物质平衡负趋势更为显著，并诱发海平面上升。
Analysis of the surface mass balance over the Greenland ice sheet based on regional climate model RACMO2.3
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 Neth-erlands 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 sig-nificant,which will induce sea level rise and should be paid more attention to.
Greenland ice sheetsurface mass balanceregional climate modelRACMO2.3
万方数据
维普
