太原一次持续性雾霾天气过程中大气电场特征及影响因子

Characteristic and Influence Factors of Atmospheric Electric Field During a Continuous Fog and Haze Weather Process in Taiyuan

利用山西省太原观象台的大气污染资料和小店气象站的气象观测资料,对2013年1月19—23日太原地区一次持续性雾霾天气过程的大气电场特征进行分析。结果表明:(1)雾霾过程中大气电场发生剧烈变化,不仅极值有较大变化,出现陡升陡降,且电场极性出现多次转变,电场强度的绝对值比晴天大气电场减少30%;(2)雾霾天气下大气电场与相对湿度有较高的负相关性,相对湿度较高是雾霾过程中大气电场值变为负值的主要原因;(3)相对湿度降低导致气溶胶脱水形成干气溶胶是雾霾过程中大气电场转为正值的主要原因,大气电场形成机制的影响使得部分时段在相对湿度降低时大气电场仍为负值。

Based on the atmospheric pollution data from Taiyuan Observatory,and the meteorological observation data of Xiaodian station,characteristic of atmospheric electric field during a continuous fog and haze weather process occurring from 19 to 23 on January2013 in Taiyuan area was analyzed. The results are as follows：（ 1） The atmospheric electric field during the fog and haze weather process changed dramatically,not only the extreme value exhibited rapid variation,but also the electric field polarity changed several times. The absolute value of the electric field intensity was reduced by 30% compared with the atmospheric electric field under the fair weather condition.（ 2） There was a high negative correlation between atmospheric electric field and relative humidity under the haze weather condition. High relative humidity played an important role in the negative value of atmospheric electric field during the haze process.（ 3） The decrease of relative humidity led to the formation of dry aerosol,which was the main reason for the positive value of electric field under the fog and haze weather process. The influence of formation mechanism of atmospheric electric field made the atmospheric electric field still negative in some periods when the relative humidity decreased.