Study On Temporal And Spatial Variation Characteristics And Climate Response Of "Three Polar" Ice Lake Based On Multi-source Remote Sensing Data

As a sensitive indicator of climate change,the temporal and spatial change of"three polar"ice lake is of great significance to the study of global climate.Based on Landsat 2000-2019,this paper studies the emery and Larsen a ice shelves in Antarctica,the southwest of Greenland ice sheet in the Arctic and the western part of Nianqing Tanggula in the Qinghai Tibet Plateau ETM+/OLI image,ASTER image and Lima mosaic image,combined with digital elevation model,the normalized water body index and visual interpretation method are used to extract ice lake area information to analyze its temporal and spatial change characteristics,and the temperature,sea temperature,precipitation and other data are used to analyze the climate change rules of the study area,and finally explore the phase of the two according to the response difference between the temporal and spatial change of the"three polar"ice lake and the climate The main results are as follows:First,the temporal and spatial characteristics of ice lake.(a)The ice lakes in the emery and Larsen a ice shelves are mainly concentrated in the internal low-altitude areas.From 2004 to 2019,the area of the ice lakes in the Antarctic increased by281.44km2,showing a fluctuating growth.From 2003 to 2016,the area of the ice lakes in the Larsen a ice shelf increased by 86.77km~2;(b)the ice lakes in the southwest of Greenland ice sheet showed a trend of expansion to the inland high-altitude areas,showing an overall fluctuating increase in the area However,the ice lake area in 2019is 33.65km~2 less than that in 2000.(c)From 2000 to 2019,the area of glacial lake in the western part of Tanggula in Nianqing increased by 3.54km~2.It mainly exists in the area above 5300m.Second,the characteristics of climate change.(a)From 2000 to 2019,the temperature of the Emory ice shelf has an obvious upward trend,while the temperature of Larsen a has a slight downward trend,and the regional sea temperature of the two regions has an obvious upward trend.(b)The temperature in the southwest of Greenland ice sheet increased,but the precipitation fluctuated regularly.(c)From 2000to 2019,the temperature and precipitation in the west part of Tanggula in Nianqing increased obviously.(d)From 2000 to 2019,the temperature of the three study areas,the emery ice shelf,the southwest of Greenland ice sheet and the west part of Nianqing Tanggula,showed an obvious upward trend,with an average annual growth rate of0.21?/a,0.30?/a and 0.31?/a,respectively.Thirdly,the response of ice lake to climate change is different.(a)Emory ice lake is more sensitive to temperature change(correlation coefficient 0.78687),but the effect of sea temperature on the formation of Emory ice lake is not significant,Larsen a ice lake is more closely related to the regional sea temperature(correlation coefficient0.95237),but its relationship with the regional temperature is not significant,which may be related to the altitude and thickness of the ice shelf,the elevation of the Emory ice shelf is higher,and the ice layer is thicker;(b)From 2000 to 2019,the ice lake in the southwest of Greenland ice sheet has a strong response to the temperature(correlation coefficient 0.4832),but a weak response to the regional precipitation(correlation coefficient 0.4019).From 2000 to 2009,the ice lake has a strong response to the regional temperature(correlation coefficient 0.6473),but after 2009,the ice lake in the region is more sensitive to the precipitation change(correlation coefficient0.6241).(c)In 2000-2019,compared with the regional precipitation of Nianqing Tanggula,the ice lake is more sensitive to the regional temperature(correlation coefficient 0.7943).