Tropospheric ozone behavior observed in Indonesia

The variation of the surface and free tropospheric ozone has been observed at Watukosek (7.5°S, 112.6°E), Indonesia. This paper is to report the analysis of the ozonesonde data obtained during the period November 1992–June 1994. A seasonal variation of ozone is evident in the lower and middle troposphere, with the maximum occurring in September and October. In the upper troposphere, seasonal variation is not evident, but enhancements were occasionally detected in April, May and June. A common feature that ozone mixing ratio is nearly constant of 20–30 ppbv throughout the troposphere is identified as a basic type of altitude profile appearing in the wet season, December through March, and in the middle of the dry season, July and August. Two other features are occasionally found. One appearing in April, May and June exhibits an enhancement over 50 ppbv in the upper troposphere, and the other appearing in September and October exhibits an enhancement in the lower and middle troposphere.