TROPOSPHERIC OZONE MEASUREMENTS OVER THE GREAT ATHENS AREA DURING THEMEDCAPHOT-TRACE CAMPAIGN WITH A NEW SHOT-PER-SHOT DIAL INSTRUMENT - EXPERIMENTAL SYSTEM AND RESULTS

Within the MEDCAPHOT-TRACE program of the European Community Tor study ing the photochemical air pollution over the Great Athens Area, we rep ort on 3-D lidar measurements of tropospheric ozone. After a general p resentation of the DIAL technique, the experimental layout of our syst em which is equipped with a unique capability for real-time analysis o f each individual optical backscattered signal is briefly described an d its performance is assessed. The temporal evolution of the ozone con centration up to the top of the boundary layer is then followed over a few days. Ln particular, the first day of the photochemical smog epis ode is presented and commented. (C) 1998 Elsevier Science Ltd. All rig hts reserved.