Characteristics of Surface Atmospheric Electric Field Under Atmospheric Pollution Conditions in Beijing Urban Area

It is well known that aerosols can absorb small ions, which dominate the conductivity of air．Variation of fair weather atmospheric electric field is closely related to the variation of aerosol concentrations and related meteorological parameters such as temperature stratification and humidity．As the concentration of aerosol increases, the concentration of small ions decreases, the conductivity decreases, the near ground static electric field increases as well．To a certain degree there is a correlation between atmospheric electric field and atmospheric environment, especially PM2.5. So it is a useful way to analyze the process of atmospheric pollution by using time series of atmospheric electric field data.

The purpose of this work is to analyze the characteristics of atmospheric electric field in different weather conditions and relation between electric field and other meteorological elements based on one year high temporal resolution ground atmospheric electric field and various meteorological elements data. As air pollution in Beijing has been heavily concerned in recent years, it is significant to find empirically quantitative relationship between electric field and aerosol concentration such as PM2.5.

The results indicate that clear days in different seasons have similar diurnal variations patterns and exhibits a double oscillation with trough at around 2：00 and 16：00 and peak at 12：00 and 20：00(Beijing time)．However, the magnitude of diurnal variation varies greatly in different Seasons. Also, during different weather system, typical diurnal variation are destroyed and other characteristics are shown

As heavy polluted conditions in Beijing are generally happened in stable weather system with wind from south and with relatively high humidity, probably because aerosols are easy to be accumulated near the surface. Several cases will be studied to understand these processes.