青藏高原气候与冰冻圈变化研究进展

Research Progress on Climate and Cryosphere Changes in the Qinghai-Tibetan Plateau

青藏高原是全球气候变化最敏感、最具指示性的区域,也是中低纬度地区冰冻圈最发育的地区。近几十年来,全球气候变化对青藏高原冰冻圈产生了广泛而深刻的影响,成为气候系统多圈层相互作用研究的热点地区。本文利用气象台站观测资料分析了高原气候变化特征,梳理了高原冰冻圈关键要素(冰川、积雪、冻土)的时空变化研究进展。总体来看,1961-2021年青藏高原暖湿化特征明显,气温变化率为0.33℃/(10 a)(P<0.01),降水量变化率为8.63 mm/(10 a)(P<0.01),直接影响冰冻圈关键要素(冰川、积雪、冻土)的时空演化。青藏高原冰川整体呈退缩和亏损态势,东部和南部的冰川萎缩速率较大,平均积雪面积在2000年以后显著减少,积雪日数逐年递减,积雪深度在2000年之后出现显著下降且存在空间异质性。1980年以来青藏高原多年冻土、季节冻土面积呈显著减小趋势,其中季节冻土冻融周期缩短,冻结日期推后、解冻日期提前。目前,青藏高原气候要素观测依然不足,特别是针对冰川、冻土、积雪等冰冻圈要素的业务化观测明显不足。建议多部门协作、统一规范,构建以“水”和“防灾减灾”为主线的综合观测系统,强化气温、降水、冰川、冻土和积雪等关键气候变量的一体化监测、预测和服务能力,填补我国山地气候与气候变化业务的空白,为青藏高原水资源管理及经济社会可持续发展提供数据支撑。

The Qinghai-Tibetan Plateau is the most sensitive and indicative region of global climate change and is also the area of typical cryosphere development in the middle and low latitude regions.In recent decades,climate and cryosphere changes have become a hot topic in the study of multilayer interactions of climate systems,as global climate change has extensive and profound impacts on the cryosphere of the Qinghai-Tibetan Plateau.In this study,we analyzed the characteristics of climate change on the Qinghai-Tibetan Plateau using observation data from 94 meteorological stations on the plateau,summarized the research progress on the spatial and temporal evolution of key elements of the plateau cryosphere(glaciers,snow cover,permafrost).Overall,the climate of the Qinghai-Tibetan Plateau from 1961 to 2021 showed significant warming and humidifying characteristics,with an average annual temperature increase rate of 0.33℃/(10 a)(P<0.01)and an annual precipitation increase rate of 8.63 mm/(10 a)(P<0.01).This directly affected the spatial and temporal evolution of the key elements of the cryosphere(glaciers,snow cover,and permafrost).The glaciers on the Qinghai-Tibetan Plateau generally showed retreat and loss,with greater rates of glacier shrinkage in the east and south.After 2000,the snow depth on the Qinghai-Tibetan Plateau decreased significantly,the number of snow days decreased year by year,and the snow depth decreased significantly with spatial heterogeneity.Since 1980,the area of perennial permafrost and seasonal permafrost on the plateau showed a significant decrease,the seasonal permafrost shortened the freeze-thaw cycle,the freezing date was postponed,and the thawing date was pushed forward.At present,there is still insufficient observation of climate elements on the Qinghai-Tibetan Plateau,especially the operational observation of cryosphere elements such as glaciers,permafrost and snow cover.It is recommended to coordinate and standardize multi-departments,establish a comprehensive observation network system for the cryosphere with‘water’and‘disaster prevention and reduction’as the principle lines,and strengthen the integration of monitoring,prediction,early warning and service of key meteorological variables such as temperature,precipitation,glacier,permafrost and snow cover.It will fill the gaps in China′s mountain climate and climate change operation and provide data support for water resource management and sustainable economic and social development on the Qinghai-Tibetan Plateau.