全球变暖背景下中国东部季节性冻土的变化特征及其与季风活动的可能联系

Variation of Seasonal Frozen Soil in East China and Their Association with Monsoon Activity under the Background of Global Warming

摘要: 利用国家气候中心提供的1962~2001年逐月平均土壤温度资料，通过拉格朗日插值方法得到的0℃等温线深度表征冻土深度，研究了全球变暖背景下我国东部冬季季节性冻土的时空演变特征及其与季风活动的可能联系。结果表明，我国东部季节性冻土的深度呈现出北深南浅、西厚东薄的空间分布形势，区域性差异显著。1980年以来，研究区内季节性冻土深度由深变浅，南缘线北缩，冻土退化趋势显著。季节性冻土的变化与东亚冬季风的活动关系密切，强(弱)季风年，冻土南边缘位置偏南(北)，其中东部区域冻土南边缘的位置对东亚冬季风的响应最为敏感。

Abstract: Using 1962-2001 monthly soil temperature data provided by National Climate Center, the depth of 0°C iso-therm obtained with Lagrange interpolation method is used to express the frozen soil depth, and the spatial and temporal variations of the frozen soil depth in East China under the background of global warming and its association with winter monsoon activity has been investigated. Results show that the seasonal frozen soil depth in East China exhibits evident regional difference. In general, the seasonal frozen soil depth is deeper in the north part and shallower in the south part, also thicker in the west part than that in east part. Meanwhile, the frozen soil depth becomes shallower with its south edge retreating northward since 1980s, which indicates a significant degrading trend of the seasonal frozen soil. Varia-tions of seasonal frozen soil have close relationship with East Asia winter monsoon. It is revealed that the south edge of the frozen soil depth experiences a southward (northward) movement in the strong (weak) winter monsoon years. In addition, the south edge of the frozen soil depth in the eastern part is more sensitive to the anomalous activity of East Asia winter monsoon.