新疆干旱区气溶胶间接效应区域性分析

利用MODIS气溶胶和云资料以及实测的降水数据，可从宏观角度分析新疆区域气溶胶时空分布特征，研究气溶胶与云和降水之间的相互影响关系.结果表明：近十年来受区域暖-干趋势的转变影响，新疆地区气溶胶光学厚度空间分布呈现显著的区域性和季节性差异；南疆地区气溶胶光学厚度整体高于北疆地区，春、夏高，秋、冬低，整体呈现增加趋势，其中，北疆地区气溶胶光学厚度变化程度相对较为显著；受气候变化和颗粒粒径差异影响，新疆干旱区云光学厚度与气溶胶光学厚度呈负相关变化趋势，相关系数北疆地区高于南疆地区；云水路径受温度、湿度影响较大，对气溶胶光学厚度的变化的敏感程度北疆大于南疆，夏季最高，冬季最低；气溶胶光学厚度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，云滴粒子有效半径与气溶胶光学厚度呈负相关，说明在干燥地区或季节，气溶胶的增加，抑制云滴粒子的增长；整体来看，新疆干旱区气溶胶的增加抑制了区域降水的形成.

Regional analysis of aerosol indirect effects in Xinjiang region

Aerosol optical depth and cloud data from satellite measurements, the precipitation data from ground observations were used to evaluate the spatial-temporal variations of aerosol characteristics and the interaction between aerosols, cloud and precipitation. The results showed:1. The spatial distribution of aerosol optical depth in Xinjiang had a significant regional and seasonal variation due to the change of regional warm-dry conditions over the last decade. 2. The aerosol optical depth in South Xinjiang was higher than North Xinjiang. It was high in spring and summer and low in autumn and winter. It demonstrated an increasing trend. Wherein, aerosol optical depth in North Xinjiang changes more significantly. 3. There was a negative correlation between cloud optical depth and aerosol optical depth. Due to the influence of climate changes and size differences among particles, the correlation coefficient between cloud optical depth and aerosol optical depth in North Xinjiang was higher than South Xinjiang. 4. The cloud water path was greatly affected by temperature and humidity, and the sensitivity of the change of aerosol optical depth was greater than the southern. It was highest in summer and lowest in winter. 5. The relationship between aerosol optical depth and effective radius of cloud droplets was complex. They were greatly influenced by water vapour. When the water content in clouds was low, the effective radius of cloud droplets was negatively correlated with the aerosol optical depth. This indicated that the increase of aerosols in dry areas or seasons will inhibit the increase of cloud droplets. On the whole, the increase of aerosols in Xinjiang province suppressed regional precipitation.