A possible positive feedback of reduction of precipitation and increase in aerosols over eastern central China
A possible positive feedback of reduction of precipitation and increase in aerosols over eastern central China
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DOI：
10.1029/2006gl025959
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发表时间：
2006-06
影响因子：
5.2
通讯作者：
Chunsheng Zhao;X. Tie;Yun Lin
中科院分区：
文献类型：
--
作者：
Chunsheng Zhao;X. Tie;Yun Lin
本文利用中国中东部地区的实测降水资料、MODIS资料和探空资料进行了分析。结果表明，近40年来该地区降水明显减少，且这种减少与气溶胶的高浓度有很强的相关性。气象探测数据表明，在过去的17年里，对流层的大气稳定性一直在增加。推测对流层下部的气溶胶层影响辐射过程，从而导致大气稳定性的变化。大气稳定度的增强有抑制该地区上升运动和降水的趋势。由于降水在冲刷过程中对气溶胶粒子的汇起主要作用，降水减少会导致气溶胶粒子的增加。这种可能的正反馈循环(多气溶胶→少降水→多气溶胶)将导致中国中东部地区降水减少的加速过程。
In this study, observed precipitation, MODIS data and meteorological sounding data over eastern central China were analyzed. The result shows that the precipitation in this region is significantly reduced during the last 40 years and this reduction of precipitation is strongly correlated to the high concentrations of aerosols. Meteorological sounding data indicates that the atmospheric stability in the troposphere has been increasing during the last 17 years. It is speculated that the aerosol layer in the lower troposphere affects the radiative processes, which lead to changes in atmospheric stability. The enhancement in the atmospheric stability tends to depress upward motion and precipitation in this region. Because precipitation plays a major role for the sink for aerosol particles through washout process, less precipitation will lead to an increase in aerosol particles. This possible positive feed back cycle (more aerosols → less precipitation → more aerosols) will induce an acceleration process for the reduction of precipitation in eastern central China.