Measurement of Changes in Lower Tropospheric Ozone Distribution through One Day Using a Compact UV Solar-Blind Lidar

Abstract

Successive measurements of atmospheric ozone up to an altitude of 3km through 24 hours have been made using a differential absorption lidar (DIAL). The wavelengths 277nm and 313nm were chosen for the DIAL taking into account the solar-blind effect due to to the stratospheric ozone. The performances of the compact ozone lidar developed are evaluated in the actual lidar observations, and it is demonstrated that the lower tropospheric ozone can be measured in daytime without deterioration in the SN ratio if the solar-blind effect is considered. The errors in the ozone concentration due to aerosols, NO2 and 502 are discussed and the data are corrected for the aerosols. It is expected that the altitude range can be extended from the ground to 10km, making upward and downward observations from an airplane at altitudes of 3km and 6km. In three sets of successive measurements, the lidar was used to observe the ozone around the boundary between the free atmosphere and the Ekman layer. In the absence of a surface inversion layer, the nighttime ozone density in the mixed layer decreased considerably.