冰川反照率影响着冰川表面能量收支状况，其强烈的反馈机制是驱动冰川物质平衡变化的关键因素。本文基于MOD10A1和MYD10A1反照率产品、萨吾尔山冰川物质平衡大地测量法结果、木斯岛冰川实测反照率及物质平衡，开展了2000-2022年萨吾尔山冰川反照率变化及物质平衡估算研究。结果表明，2000-2022年，消融期内萨吾尔山冰川平均反照率下降了约0。035，变化速率约为0。0015 a-1。最小反照率最早出现时间为6月16日，最晚出现时间为9月8日，平均以10 d·(10a)-1的速率提前。在95%的置信水平下，木斯岛冰川反照率-物质平衡模型(A-Ms模型，即单条冰川模型)的决定系数R2为0。84。基于冰川编目及现场环境考察，将萨吾尔山冰川划分为冰斗冰川、山谷冰川和悬冰川，对应类型的A-Mr模型(区域冰川模型)的决定系数R2分别为0。81、0。74和0。72。2000-2020年，A-Ms模型重建萨吾尔山冰川物质平衡值为-1。24 m w。e。·a-1，A-Mr模型相应的重建值为-0。90 m w。e。·a-1，A-Mr模型模拟结果更能反映萨吾尔山冰川的物质损失状况。与亚洲高山区各山地冰川相比，萨吾尔山冰川物质损失最大。
Glacier surface albedo changes and mass balance estimation in the Sawir Mountains,Central Asia
Net shortwave radiation provides the main melting energy for mountain glaciers,which is modulated by a combination of glacier surface albedo and incoming shortwave radiation.Glacier mass balance,as a link be-tween atmosphere and glaciers,is an important glacier parameter that characterize glacier accumulation and melt-ing,and is sensitive to climate change.Many scholars have used the albedo method to study mass balance for an individual glacier,but less attention has been given to large-area glaciers.This study helps to understand that glacier melting is a result of climate and atmospheric changes,as well as feedback from glacier surface albedo.In order to investigate variations of glacier surface albedo from 2000 to 2022 in the Sawir Mountains and further estimate annual mass balance,two models(A-Ms and A-Mr)between albedo and mass balance were established based on MOD10A1 and MYD10A1 snow products retrieved glacier surface albedo,geodetic mass balance in the Sawir Mountains,in situ measured albedo and mass balance on Muz Taw Glacier.During ablation season,glacier albedo decreased by 0.035 in the Sawir Mountains at the rate of 0.0015 a-1,and dates of minimum albe-do appeared to have a shift towards earlier at the rate of 10 d·(10a)-1.The A-Ms model established a linear rela-tionship between albedo and mass balance on Muz Taw Glacier at the 95%confidence level,and indicated that a strong linear coefficient(R2=0.84)was found between albedo changes and mass balance.For A-Mr model,the R2 between albedo and mass balance in cirque,valley and hanging glaciers in the Sawir Mountains were 0.81,0.74 and 0.72 at the 99%confidence level,respectively.The reconstructed two albedo-mass balance relation-ships can be used to retrieve glacier mass balance.Furthermore,average annual mass balance in the Sawir Mountains estimated from A-Ms and A-Mr models were-1.24 m w.e.·a-1 and-0.90 m w.e.·a-1,respectively.Mass balance estimated from A-Mr model was closer to geodetic mass balance,which could better reflect mass loss in the Sawir Mountains.In addition,compared with glaciers in High Mountain Asia,glacier mass loss in the Sawir Mountains was the greatest.Glacier mass loss in the northern and western regions of High Mountain Asia was smaller than that in the southeast,and in recent years,glacier mass in High Mountain Asia had been in a state of severe loss.
glacier surface albedoglacier mass balanceSawir MountainsMuz Taw GlacierMODIS
NETL
NSTL
万方数据
