Multi-year investigations of aerosol layer using lidar measurements at Chung-Li, Taiwan

Height, evolution and structure of the nocturnal aerosol layers in the lower troposphere is reported by using a ground-based lidar over Chung-Li (24.58∘N,121.10°E), Taiwan, during the period from March 2002 to December 2008. Investigation shows that the aerosol layers mainly distributed at an altitude range between 0.2 and 3 km. The mean height and depth of the aerosol layer are 0.57±0.11 km and 0.63±0.14 km, respectively. Seasonality is observed for the depth and height of the aerosol layer. The wind shear and temperature inversion is calculated from the radiosonde data. The statistical interpretation shows a correlation between lidar-derived aerosol layer height and wind shear and also with the temperature inversion. The depth and height of aerosol layer have a positive correlation with Bulk Richardson number. The seasonal features of tropospheric aerosols and their impact on the PM10 mass concentrations are also examined.

► Nocturnal aerosol layer (NAL) is investigated form lidar observation.
► Seasonality is observed for the depth and height of NAL.
► NAL have an impact on the ground air pollutant.