北半球冰川物质平衡变化的若干特征及其气候意义

根据北半球连续观测的４０多条冰川物质平衡资料，分析了目前冰川物质平衡状态及影响它们的地形因互。冰川物质平衡的变化在区域间存在着一定的联系：斯堪的纳维亚、落基山和天山地 区冰川物质平衡的变化在大多数时间内存在着对应联 系，而与阿尔卑斯山冰川物质平衡的变化具有不同程度的反向波动特征。

VARIATIONS OF GLACIER MASS BALANCE AND THEIR CLIMATIC IMPLICATION

Based on data of mass balance for more than 40 glaciers which are continiously mesaured in the last thirty to fourty years,this parer discusses relationship between mass balance conditions and topographical factors,concerns with some characteristics of mass balance varations for the main glacier areas of the northern hemisphere and analyses sensitivity between ELA and mass balance and sensitivity of mass balance to climatic change. Under the groundback of present climatic warming, mass balance for most of glaciers appear to be negative, but positive balance for a few glaciers also exist. Besides uncertainty of measurements and other factors,appearance of positive balance is largely related to the orientation of glacier with respect to the predominant humidity sources as well as to the distribution of glacier surface area with altitude (hypsometry). It reflects to the large extent that glaciers have to depend upon topographical and itself conditions to reduce effect of climatic warming on them. In regional scale, the topographical conditions glaciers subsist in Tianshan and Rocky Mountains are not totally able to restrain effect of climatic warming on mass loss.Variatoins of mass balance are quite comparable in regions.Fluctuations of mass balance in Scandinavia, Rocky Mountains and Tianshan Mountains mostly show corresponding connection However, compared with glaciers in the Aples, slight anti variations seem to exist between mass balance series in the above regions and the Aples. For the tendency of mass balance variations, from south to north, mass balance appears to tend from decrease to increase. Sensitivity of mass balance shift to ELA is associated with balance conditions: the more mass balance tends to accelerate negative balance, the more larger sensitive value is. Loss of mass balance in various regions corresponds to rise of 0.7 ～1.2℃ in air temperature relative to zero balance (stable state) in the last thirty to fourty years.