近50年来北极斯瓦尔巴地区冰川物质平衡变化特征

Variation characteristics of glacier mass balance in Svalbard,Arctic,in recent 50 years

利用长时间序列的冰川物质平衡资料,详细分析了北极斯瓦尔巴地区冰川的物质平衡变化特征以及气候因子对物质平衡的影响。结果表明:近50年来斯瓦尔巴地区冰川物质平衡变化主要呈负平衡、零平衡/略微增长两种状态。冰川净平衡一般为负值,年际变化波动幅度较大且呈负平衡趋势,累积物质平衡表现出长期稳定的负平衡增长态势。除Kongsvegen冰川外,其他冰川不存在短期内的平衡波动。季节变化表现为夏季消融、冬季积累,且夏季消融比冬季积累波动更大,冰川净平衡与夏季消融保持同步变化趋势。冰川净平衡与平衡线高度(ELA)呈负相关(平均相关系数为-0.89),与积累区面积比率(AAR)呈正相关(平均相关系数为0.84),该地区大多数冰川AAR减小,说明冰川物质补给处于劣势,冰川物质平衡向负平衡发展。夏季气温升高是斯瓦尔巴地区冰川表面物质加速亏损的直接原因。

This research aims at analyzing mass balances of seven glaciers in Svalbard, Arctic, including Austre Brggerbreen, Austre Lov6nbreen, Hansbreen, Irenbreen, Kongsvegen, Midtre Lov6nbreen and Waldemar- breen, by using their long-time series of mass balance. Also, the effects of temperature and precipitation on the mass balance are discussed. Results show that： In recent 50 years, glacier mass balance in Svalbard has been mainly in negative balance and zero balance with slightly positive balance two states. Cumulative mass balance has showed a negative balance without fluctuation in a short term, except for Kongsvegen. Seasonally, there has been ablation in summer and accumulation in winter, with ablation in summer more than accumulation in winter. Between glacier mass balance and the equilibrium line altitude （ELA）, there is a negatively correlation （mean R = -0.89） ; between glacier mass balance and the accumulation area ratio （AAR）, there is a positively corre- lation （ mean R = 0.84）. Most glacier accumulation area ratio is going to decrease, showing glacier mass supply is in a disadvantage, resulting in a negative balance of glacier mass. Summer temperature increasing is probably a direct cause for accelerating glacier mass loss.