2000-2020年格陵兰冰盖夏季表面温度变化及其对物质平衡的影响

Summer surface temperature change of Greenland Ice Sheet from 2000 to 2020 and its effect on mass balance

基于MODIS温度产品,着重分析了2000-2020年格陵兰冰盖夏季表面温度和表面融化范围的年际变化趋势;联合IMBIE(冰盖物质平衡对比实验)数据分析表面温度对于冰盖物质平衡的影响;进一步讨论了大气环流对于格陵兰冰盖表面温度变化的影响。结果表明:格陵兰冰盖夏季表面温度和融化范围趋势较为一致,2000年初期呈现出显著的上升趋势,2012年达到峰值,随后波动下降;整个研究阶段北部区域是增温速率最大的区域,高于其他任何区域两倍,东南部和西南部是温度最高的区域却具有最小的增长率;格陵兰冰盖夏季表面温度、融化范围以及物质平衡之间都具有显著的相关性,同时格陵兰冰盖夏季表面温度每上升1℃,会导致其物质损失增加74.29Gt·a;最后,经过对北大西洋涛动(NAO)和格陵兰阻塞指数(GBI)指数的分析得到,格陵兰冰盖夏季表面温度受到GBI的影响要强于NAO的影响,冰盖夏季表面温度和NAO呈现出负相关(r=-0.64,P<0.05),和GBI呈现出正相关(r=0.77,P<0.05)。

The monitoring of the Greenland Ice Sheet is of great significance to global and Arctic climate change. As the largest Ice Sheet in the Northern Hemisphere,the Greenland Ice Sheet is critical to the climate response and has always been the focus of global attention. Based on the MODIS temperature product data,this paper analyzes the interannual trend of the Greenland Ice Sheet summer surface temperature and surface melting range from2000 to2020. The effect of surface temperature on the mass balance of the Greenland Ice Sheet is analyzed with IMBIE data,and the effect of atmospheric circulation on the surface temperature of the Greenland Ice Sheet is discussed. The results show that the trend of summer surface temperature and melting range of the Greenland Ice Sheet is consistent,showing a positive upward trend from2000 to2012,reaching a peak in2012,and then showing a downward trend of fluctuation. The northern part of the Greenland Ice Sheet had the highest rate of warming during the study period,more than twice as fast as any other region,the south-east and southwest had the highest temperatures but the lowest growth rates;And there was a strong correlation between the Greenland Ice Sheet’s summer surface temperature,the extent of melting,and the mass balance,at the same time,an increase of1°C in the summer surface temperature of the Greenland Ice Sheet will lead to an increase of74.29 Gt·ain mass loss. Finally,the NAO(North Atlantic Oscillation)and GBI(Greenland blocking index)indices are analyzed,the influence of GBI on the surface temperature of Greenland Ice Sheet in summer is stronger than that of NAO. Greenland Ice Sheet surface temperature is negatively correlated with NAO(r=-0.64,P<0.05)and positively correlated with GBI(r=0.77,P<0.05).