中亚地区气溶胶时空分布及其对云和降水的影响

发布时间：2018-07-14 08:47

【摘要】：中亚地区属干旱半干旱气候区,是水资源缺乏最严重的地区之一,也是全球沙尘气溶胶贡献度较大的区域.利用MODIS气溶胶和云资料以及校准后的TRMM降水数据,可从宏观角度分析中亚地区气溶胶、云、降水的时空分布特征,研究气溶胶与云和降水之间的相互影响关系.结果表明:1中亚地区年平均气溶胶光学厚度表现为春季(0~1)夏季(0~0.8)冬季(0~0.42)秋季(0~0.38),2002—2013年间整体呈现增加趋势;冬季COD量值明显高于其他3个季节,12年间整体表现出下降趋势,夏季变化较小,增幅为-0.876%,冬季最大,增幅为-1.713%;云水路径的区域性和季节性变化较为明显,整体处于降低趋势,其中秋季的新疆塔里木盆地变化最为显著,年变化为-6.607%;利用实测降水数据对TRMM月降水数据进行校准处理,可有效提升数据精度,新疆境内夏季降水占年降水量的比重较大,春、秋次之,咸海地区降水量年内分配相对较均匀,季节性差异不明显,中亚干旱区作为一个整体,降水呈现出增加趋势,其中,冬季降水的增加趋势最明显.2气溶胶光学厚度与云光学厚度呈负相关;与云滴粒子有效半径关系复杂,受水汽影响较大,在云层含水量较低的情况下,云滴粒子与气溶胶光学厚度呈负相关,而在云层含水量较高的情况下,二者呈正相关;云水路径随着气溶胶光学厚度的增加而减小,随AOD的变化的敏感程度在秋季最高,冬季最低.3气溶胶和降水关系复杂,整体来看,中亚地区气溶胶抑制降水.
[Abstract]:Central Asia is an arid and semi-arid climate zone, which is one of the regions with the most serious shortage of water resources, and is also a region with a large contribution of dust aerosol. Using MODIS aerosol and cloud data and calibrated TRMM precipitation data, the spatial and temporal distribution characteristics of aerosol, cloud and precipitation in Central Asia can be analyzed from a macro point of view, and the interaction between aerosol and cloud and precipitation can be studied. The results showed that the annual average aerosol optical thickness in the Central Asian region of 1: 1 was increased in spring (0 / 1), summer (0 / 0.8) and winter (0 / 0.42) / autumn (0 / 0.38) / 2002 / 2013, and the COD value in winter was obviously higher than that in the other three seasons. The change in summer was small, the increase was -0.876 and the biggest in winter was -1.713.The regional and seasonal changes of cloud and water path were obvious, and the overall trend was decreasing, among which the Tarim Basin in Xinjiang in autumn had the most significant change. The annual variation is -6.607.Using the measured precipitation data to calibrate the monthly precipitation data of TRMM, the accuracy of the data can be improved effectively. The summer precipitation in Xinjiang has a large proportion of annual precipitation, followed by spring and autumn. The distribution of precipitation in the Aral Sea region is relatively uniform in the year, but the seasonal difference is not obvious. The precipitation in the arid area of Central Asia as a whole shows an increasing trend, among which, The increasing trend of precipitation in winter is most obvious. 2. The optical thickness of aerosol is negatively correlated with the optical thickness of cloud, and has a complex relationship with the effective radius of cloud droplets, which is greatly affected by water vapor, and when the cloud water content is low, Cloud droplet particles have a negative correlation with aerosol optical thickness, but there is a positive correlation between cloud droplets and aerosol optical thickness, while cloud water path decreases with the increase of aerosol optical thickness, and the sensitivity of AOD changes with AOD is the highest in autumn. The relationship between the lowest 3 aerosol and precipitation in winter is complex. In the whole, the aerosol in Central Asia inhibits precipitation.
【作者单位】：新疆大学资源与环境科学学院;新疆大学绿洲生态教育部重点实验室;新疆交通职业技术学院;
【基金】：自治区重点实验室专项基金(No.2016D03001,2014KL005) 自治区科技支疆项目(No.201591101) 国家自然科学基金(No.U1303381,41261090,41161063) 教育部促进与美大地区科研合作与高层次人才培养项目自治区专家顾问团决策研究与咨询项目(No.201601044) 新疆大学优秀博士研究生创新项目(No.XJUBSCX-2014012)~~
【分类号】：X513;P426

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