南阳市霾天气的气候特征及影响因素分析

Nanyang Haze Weather Climate Characteristic and Influencing Factor Analysis

利用南阳市气象观测站1971-2007年地面气象观测资料,对南阳市霾天气气候特征及其影响因素进行分析,结果表明:南阳市霾日数的年代际变化非常明显,2001年以前呈上升趋势,2001年以后呈下降趋势。20世纪70年代霾平均日数很少,80年代呈明显增长趋势,90年代是急剧上升阶段,2001-2007年年霾日数没有增长,但仍保持在较高的水平。不同月份霾日数明显不同,霾日数最多为1月,最少为8月。南阳市秋冬季霾日数占全年的64.7%,春夏季仅占35.3%。南阳市霾天气多出现在风速一般比较小(≤2 m/s),吹西南风的情况下。正变湿和负变压时,霾出现最多,相对湿度的增强和气压场的减弱更有利于霾的形成。连续不降雨的日数越长,出现霾的概率就越大。

This article uses Nanyang weather station 1971-2007 surface weather observation material, analyzes Nanyang haze weather climate characteristic and the influencing factor. The results indicate that Nanyang haze days interdecadal changes are obvious, assumes the increasing trend before 2001 and declining trend after 2001. The mean haze days was few in the 1970s, obvious increasing trend in the 1980s, sudden ascent stage in the 1990s. The haze days didn＇ t grow year after year from 2001 to 2007, but still maintained at the high level. Different months haze days are obvious different, the haze clays are most in January and least in August. The Nanyang haze days accounts for the whole year 64.7% in autumn and winter, only accounts for 35.3% in spring and summer. Nanyang haze often appears in the wind when the wind speed is quite generally small （ ≤2 m/s） , the wind direction is southwest. The haze presents most in positive wet and negative allobaric situation, the enhancing relative humidity and the weak pressure field is more advantageous to the haze formation. If does not rain continuously, the probability of haze is much bigger.