中文摘要：

以大气RH（相对湿度）为基准对上海2005─2009年大气质量和气象资料的日均观测资料进行了分类统计,分析了RH与ρ（PM10）、大气能见度的相关关系.结果表明：在将RH以5%的间隔进行分段后,各区段ρ（PM10）平均值与RH平均值呈显著线性负相关,R（相关系数）达0.97;随着RH增大,大气能见度随ρ（PM10）变化率的绝对值增大;RH在75%以上时,增加相同的ρ（PM10）所导致的大气能见度下降量是RH在40%～45%时的5倍以上;RH小于75%时,大气能见度可较好地反映ρ（PM10）的变化,而RH大于75%时,大气能见度的降低主要反映PM10含水量的快速增加而并不指示ρ（PM10）的增加.

英文摘要：

The relationships among relative humidity,PM10 mass concentration and atmospheric visibility were investigated using reorganized daily air quality and meteorological data for Shanghai during 2005-2009.When the data were sorted and averaged over 5% intervals of relative humidity,a strong negative correlation（R=0.97） was found between PM10 concentration and relative humidity.It was found that the rate of change of visibility versus PM10 increased with increasing relative humidity.With relative humidity above 75%,the visibility degradation caused by the increase of a certain amount of PM10 was five times higher than that at 40%-45% relative humidity.When the relative humidity was below 75%,the expected negative correlation was found between visibility and PM10 concentration.However,when the relative humidity was higher than 75%,visibility degradation mainly indicated the rapid increase of water uptake by the particles,which may not be a real indication of the increase in PM10 concentration.