Characterization of fog and near fog event during Paris fog field campaign
Abstract
Fog is important atmospheric phenomena interns of air quality. Low visibility as imperative fog factor may result due to high level of aerosol number concentration in affirmative meteorological condition and high relative humidity. This work analysis micro-physical and optical aerosol properties and meteorological condition of a fog (13-14March 2007) and near fog (10-11March 2007) event to improve understanding of micro-physical process during fog occurrence. Based on high decrease on visibility on foggy days(less than 1km) and near fog (between1km and 2 km), we have compared the temporal evolution of aerosol parameters (mass and number concentration, extinction and absorption coefficient) for fog and near fog event. In addition, the analysis of temporal series of meteorological parameter (temperature, humidity, wind speed, wind direction) help us to better understand the micro-physical process which are the important reason for formation removal or modification of particle and increase of fine aerosol number concentration during fog event. An increase in aerosol micro-physical or optical properties (mass, accumulation number, extinction coefficient) shows large variation in visibility. This variability is much higher in case of fog event compare to near fog. The chemical analysis used to find the influence of fog on aerosol type characteristic specially the aerosol acidity. The cation-to-anion ratio for explain how accumulation mode are acidity. There is a good correlation between the Pm2.5 and visibility during fog event with a correlation coefficient of R=0.84.
- Publication:
-
5th International Conference on Fog
- Pub Date:
- July 2010
- Bibcode:
- 2010ffcd.confE.138B