中国北方沙尘暴的气候特征及其对春季青藏高原地面感热异常的响应

选用中国185个常规气象观测站,建站～2000年历年沙尘暴日数资料,分析了近50年来中国北方沙尘暴的气候特征及其对青藏高原地面感热异常的响应。结果表明虽然单个沙尘暴过程属于一次中尺度天气过程,但年沙尘暴日数具有较好的空间一致性,在空间上有五个自然尘源区,即河西走廊、南疆盆地南缘、阿拉善高原、鄂尔多斯高原和浑善达克沙地等沙尘暴高发区。比较近50年来中国沙尘暴日数的年代际变化,总体趋势在减少,20世纪90年代是近5个年代中最少的。但20世纪末至21世纪初,中国沙尘暴日数有明显的回升趋势。进一步研究表明,中国沙尘暴与春季青藏高原地面感热关系密切,当春季青藏高原地面感热呈EOF1模态时,当年中国北方沙尘暴日数明显较常年偏多。

The Climatic Characteristics of Sand-Dust Storm in Northern China and Its Response to The Abnormal Sensible Heat of Surface in Qinghai-Xizang Plateau in Spring

conventional meteorology observation stations' data about the annual sand-dust storm days from beginning to 2000,were applied to analyze the climatic characteristics of sand-dust storm in northern China and its response to the abnormal sensible heat of surface in spring in Qinghai-Xizang plateau in recent 50 years. The results indicated: although each process of sand-dust storm belong to a process of mesoscale weather, sand-dust storm days of each year have a better coherence in space. There are five nature sand-dust source in space: Gansu corridor, southern rim of south xinjiang basin, Alashan plateau, Eerduosi plateau and Hunshandake sandlot. The comparison the interdecade variability of the sand-dust storm days in recent 50 years in China.Demonstated that the trend of the sand storm occurrence was decreasing. The days of sand-dust storm in 1990's was the least in recent 5 decade.But from end of 20 century to the beginning of 21 century, the sand-dust storm days showed an obvious trend of hoist in China. The further research indicated: in China, the sand-dust storm had an osculatory relation with the sensible heat of surface in Qinghai-Xizang plateau in spring. When the sensible heat of surface took on EOF1 mode in Qinghai-Xizang plateau in spring, the days of dust storm in northern China was obviously more than normal year.