Article
Wind, temperature, relative humidity and aerosol mass concentration were monitored simultaneously in Wuhan,
China. Several observations were found after analyzing the physical fields of these data. It was obvious that weak
pressure and saddle patterns occurred during fog-haze episodes. An inversion layer occurred before heavy fog haze events and became thicker during fog-haze events. The boundary layer structure index was relatively
higher during fog-haze days and had a significant negative correlation with the planetary boundary layer height
and turbulence parameters. Wind speeds were generally less than 5 m/s and rarely exceeded this speed on the
selected polluted days. Turbulence variation characteristics had special representations, especially before fog haze events. Turbulence intensities always reached abnormal peak values before fog-haze processes, while the
intensities remained steady before and during pollution processes with low relative humidity. Both the turbu lence kinetic energy and momentum flux decreased to near zero before heavy fog-haze processes. Momentum
flux often presented abnormal disturbances before heavy fog-haze processes. These disturbances were often in an
active phase before and during pollution processes with low relative humidity, a situation that is not similar to
fog-haze events that maintained high relative humidity. There was a feedback mechanism between solar radi ation and aerosol mass concentration, and the occurrence of turbulence anomalies may be related to the regu lation of atmospheric circulation by wave-flow interaction. The results presented in this study suggest that the
turbulence parameters, which display anomalies before the occurrence of heavy fog-haze processes under the
background of inversion layers and stable atmospheric patterns, can serve as a means of predicting disastrous
weather conditions such as fog-haze pollution