Study On Alpine Glacial Mass Balance Change And Climate Sensitivity Of Equilibrium Line Height Of The Arctic

Glacier is the product of climate,and many information of climate and environment change is stored in glacier.By studying the glaciers,we can understand the past and predict the future climate and environment change.Climate change leads to a corresponding change in the state of material budget balance on glaciers,which can also cause the changes of glaciers motion characteristic and glacier thermal state,then lead to the changes in the position,area and ice reserves at the end of the glaciers.So glaciers interact with the local climate each other.Affected by oceanic climate,Arctic mountain glaciers are more sensitive to climate change and more suitable for capturing global and regional climate change.In this paper,23 glaciers with a long time series of observational data in the Arctic region were selected as research objects,and the current situation of glacial mass balance changes was analyzed,and the main factors affecting the change of glacial mass balance in the Arctic region were discussed.A statistical relationship model was established to analyze the climate sensitivity of the height of the equilibrium line.The results were showed as follow:(1)From 1960 to 2015,the average annual mass balance of the glaciers in the Arctic region was decreasing as a whole,with an average annual mass balance of-278 mm and a cumulative mass balance of-12.72 m.Before 1990 s,the mass balance of the Arctic glacier was in a state of steady deficit The annual mass deficit of glacier began to intensify in 1990-2000 and further intensified in 2000-2010.Alaska has the largest annual glacial mass balance,followed by Svalbard.Canadian Arctic and northern Scandinavia have a small annual glacial mass balances.The minimum value of mass balance was in the Russian Arctic.(2)Regression analysis showed that there was a negative correlation between the glacial mass balance and the height of the equilibrium line.When the glacial mass balance decreases by 100 mm,the height of glaciers equilibrium line in Canadian Arctic raised the most,about 92 m.Followed by Svalbard,raised about 18 m.Northern Scandinavia and Alaska glacier equilibrium line height are both about 11 m.The elevation of the balance line of the Russian Arctic glacier was the smallest,which was only about 5 m.(3)The increase of Arctic temperature,especially in autumn and winter,is the main cause of glacial ablation,and the contribution of precipitation to glacial mass balance is small.The warming of SST(sea surface temperature)is closely related to the decrease of sea ice range.The sharp melting of Arctic sea ice increases the surface water temperature,and there is a good positive correlation between the warming of Arctic sea temperature and the rise of SST(R=0.64),which further increases the melting of glaciers.Different types of glaciers have different melting rates.As warm current increasing temperature and humidification,cold current cooling and reducing humidification,glacial accumulation and ablation were affected,and lead to the obvious difference in the annual fluctuation range of glacier mass balance.(4)The largest change in the area of Arctic glaciers was in Alaska,followed by Svalbard,Scandinavia,Iceland and the Russian Arctic,and the lowest change in the area of Arctic glaciers was in Canada.The single glacier shrank most in Iceland,followed by the Canadian Arctic and Alaska,with the Scandinavian glacier in the middle and the Russian Arctic in the lowest.(5)The height of most ice balance lines in the Arctic is on the rise,the elevation of the ice balance line in the Canadian Arctic was the most significant,followed by the northern Scandinavian glacier.The smallest elevation of the balance line was the Russian Arctic glacier.By analyzing the correlation between the height of the equilibrium line and the meteorological data,it is found that the height of the equilibrium line is highly correlated with the temperature in the warm season.The temperature rise of 1? in the warm season has the greatest influence on the height of the Svalbard glacier equilibrium line,with an average increase of 81 m,followed by the Canadian Arctic and northern Scandinavia,with the least impact on the glaciers in Alaska and the Russian Arctic.The effect of increasing or decreasing precipitation on the height of the equilibrium line is less than that of the temperature rise,but the change of the height of the glacier equilibrium line in northern Scandinavia is mainly affected by the change of precipitation.The amount of precipitation increases or decrease by 10%,and the height of the balance line will decrease or rise about 83 mm,and then followed by the Canadian Arctic.The least significant is the Russian Arctic.