【摘要】 利用东莞1957—2011年降水、能见度、相对湿度等地面观测资料,分析了东莞降水和灰霾的长期变化趋势,并探讨了气溶胶对降水长期变化趋势的影响。结果显示:东莞的降水量和不同等级降水日数均呈现明显的年际变化特征;年降水量在1990年后呈增加趋势,2007年开始呈逐渐下降趋势;痕量、微量和小雨降水日从1980年代中期后呈缓慢下降趋势,大雨、暴雨和大暴雨日数则没有明显的变化趋势;东莞的灰霾变化历经3个阶段,分别是1980年—1980年代中期、1990年代初—2000年和2000—2011年。气溶胶浓度的不断增加使降水日数减少,但对强降水的降水频率和降水强度有促进作用。更多还原

【Abstract】 The data of precipitation,visibility,relative humidity in Donguan from 1957 to 2011 are analyzed.It shows that the annual variation of precipitation and graded precipitation days was significant.There was an increasing trend after 1990 and a decreasing trend after 2007 in the annual precipitation.There was a decreasing trend in trace(no amount),slight(≤1 mm/d),and light rain days and the trend in large,heavy and very heavy rain day was not obvious.There were three phases in the change of the haze in Dongguan.The first phase is from 1980 to the middle of the 1980s,the second phase from the early 1990s to 2000 and the third phase from 2000 to the present.The increase of aerosol concentration leads to the decrease of rain days and also enhances the frequency and intensity of heavy rainfalls.更多还原