Surface ozone measurements at Bandung

Abstract

Surface ozone measurements at Bandung (6°54'S, 105°35'E), West Java, Indonesia, have been made since December 1986. Analysis of ozone concentration was conducted for the period, December 1986-December 1988. The analysis exhibits significant diurnal maximum (35 ppbv) occuring at noon, minimum (3.5 ppbv) occuring at night, and diurnal average is 17.5 ppbv. Maximum ozone concentration occurs earlier in wet month (March) than in dry month (July). This condition should be related to varying local weather and observation site condition making possible the occurance of ozone production. Significant seasonal trend of diurnal maximum is not found in December 1986-December 1988 data.

The natural ozone concentration in the troposhere is through photochemical reactions as well as transport processes from the stratosphere (Komala and Ogawa, 1991; Ilyas, 1987; Shaw, 1980). Natural tropospheric ozone near the ground surface is also produced and destroyed by chemical reactions involving free radicals. Besides the natural origin, surface ozone can be produced photochemically due to the presence of NOx, CO, methane, and nonmethane hydrocarbons (NMHC), in association with high levels of solar near-ultraviolet radiation (Ilyas, 1987; Komala and Ogawa, 1991). The global distribution of tropospheric ozone is related with global air quality, and photochemistry, and with impact on atmospheric thermal radiation field (Komala and Ogawa, 1991).