【摘要】 利用1946—2005年北极Svalbard、斯堪的纳维亚及挪威南部冰川物质平衡资料,分析了冰川物质平衡的变化特征及其对气候变化的响应.结果表明:北极Svalbard地区冰川物质平衡具有较低的年振幅和较小的年际变化;环北极的斯堪的纳维亚地区和挪威南部地区冰川物质平衡则具有较高的年振幅和较大的年际变化;20世纪80年代末90年代初,3个地区冰川物质平衡均达极大或较大值,之后呈加速向负平衡发展之势.冰川物质平衡对气候变化的敏感性与其物质平衡状态有关:物质平衡越是趋向正平衡发展的冰川,其敏感值较高,反之亦然;海洋性冰川较大陆性冰川对平衡线高度变化(气候变化)敏感.平均而言,三个地区冰川物质平衡在观测期内的亏损量相对于零平衡状态而言,相当于气温上升了0.32℃.冰川净物质平衡对1℃升温的敏感性变化范围为-0.42～-0.99mw.e..a-1,对10%降雪增量的敏感性为+0.01mw.e..a-1～+0.57mw.e..a-1;平衡1℃升温导致的冰川净物质平衡消融需要降雪量增加24%.冰川物质平衡对气候变化的敏感性与其所处气候环境背景(大陆度)相关性,越是趋向海洋性的冰川其敏感性越高.更多还原

【Abstract】 On the basis of the data of glacier mass balances during 1946—2005 over Svalbard,Scandinavia and Southern Norway,the characteristics of glacier mass balance are analyzed,and their sensitivities to climate change are calculated using a simple degree-day model.The results are as followings:1)The mass balances of glaciers in Svalbard had low annual amplitude and small interannual variability.By contrast,the mass balances of glaciers in Scandinavia and Southern Norway had large annual amplitude and interannual variability.The mass balances of glaciers in these three regions reached the maximum or comparatively high values in the late 1980s or the early 1990s.After that there was an accelerating negative tendency.2)The mass balances of glaciers in Svalbard kept in a stable negative state between the late 1960s and the middle of 1980s,subsequently,there was a short trend to zero balance.From the late 1980s to the early 1990s,the mass balances of glaciers in Scandinavia and Southern Norway showed the characteristics of positive oscillation,but there existed difference in oscillation amplitude.3)The sensitivity of glacier mass balance to ELA(or climatic)change was associated with mass balance condition:the glacier with more positive mass balance had higher sensitivity value,and vice versa.Maritime glacier was more sensitive to ELA(or climatic)change than continental glacier.In average,the loss of mass during 1946—2005 in these three regions was equivalent to the result of an air temperature rise of 0.32 in relatively to zero net balance state.The highest temperature increase was found in Svalbard with 0.55 ℃,however,only a rise of 0.12 ℃ was found in Southern Norway.4)The net balance sensitivity to hypothetical air temperature increase of +1 ℃ ranges from -0.42 to -0.99 m w.e.·a-1,and the net balance sensitivity to an assumed increase in precipitation of +10% varies from +0.01 to +0.57 m w.e.·a-1,thus,24% increase of snow precipitation is needed to compensate the net mass loss induced by air temperature increase of +1 ℃.The summer balance sensitivity to hypothetical air temperature increase of +1 ℃ varies from -0.43 to -0.87 m w.e.·a-1,and the winter balance sensitivity to an assumed increase in precipitation of +10% ranges from +0.07 to +0.31 m w.e.·a-1.The sensitivity of glacier mass balance to climatic change is correlated with climatic and environmental backgrounds(continental/maritime):maritime glaciers have comparatively higher sensitivity than continental glaciers.更多还原