Assessment and analysis of correlation between remote sensing albedo in ablation season and annual mass balance for glaciers in High Mountain Asia
Albedo is an important parameter that controls the absorption of solar radiation by the glacier surface and affects the rate of glacier ablation.Previous studies have found a significant correlation between the minimum or average albedo during the ablation season and annual mass balance in several High Mountain Asia glaciers.Due to the diverse types and complex change mechanisms of High Mountain Asia glaciers,the ability of ablation season albedo to characterize the annual mass balance in different types of glaciers and their regional characteristics needs to be further understood.Using the MODIS ice/snow albedo data and in-situ annual mass balance time series from the years 2000 to 2019,this study analyzed the interannual variation characteristics of four ablation season albedo parameters for 23 glaciers in High Mountain Asia and evaluated the correlation between different ablation season albedo parameters and annual mass balance.We also discussed the impact of albedo change on the annual mass balance in different glacial subregions and glacier types(maritime,sub-continental,and extreme continental).In the past 20 years,the albedo of studied glaciers in High Mountain Asia has shown a decreasing trend,except for those in the western Himalayas and the Qilian Mountains.The fluctuation of the minimum albedo during the ablation season is more drastic than that of the average albedo;their values are concentrated in the ranges of 0.1-0.4 and 0.3-0.6,respectively.We found that the interannual variation and the long-term trend of ablation season albedo are consistent within the same glacial subregions.Among the four ablation season albedo parameters,the average albedo derived from the eight-day composite albedo data shows the strongest correlation with annual mass balance.13 glaciers exhibited a significant linear positive correlation(P＜0.05);the highest coefficient of determination is 0.98 for the Gurenhekou glacier,and the lowest is 0.28 for Urumqi glacier No.1.Moreover,the linear correlation between ablation season albedo and annual mass balance shows no obvious regional differences and is not limited by glacier type.There are still 7 glaciers whose albedo did not show a significant correlation with the annual mass balance,mainly due to factors such as glacier size,the number of in-situ annual mass balance measurements,and the quality of albedo estimation.Our study demonstrates that the average albedo outperforms the minimum albedo in reflecting changes in annual mass balance.Since the minimum albedo represents a single time-phase value,indicating the peak absorption of solar radiation,it is susceptible to the influence of perturbing factors such as cloud cover and sudden snowfall.However,the average albedo,which integrates solar radiation absorption over the entire ablation season,better mitigates the influence of the aforementioned perturbing factors and exhibits a stronger correlation with annual mass balance.This study serves as a valuable reference for enhancing our understanding of the impact of ice and snow albedo on glacier mass balance in High Mountain Asia.
remote sensingglacier albedoglacier mass balanceMODIS ice/snow albedoHigh Mountain Asian
NETL
NSTL
万方数据
