Tropospheric ozone measurements at the equatorial region (1980-1988)

Results from surface ozone measurements at Penang (5.5 deg N, 100 deg E) over 1980-88 period are presented. The study indicates the ozone concentrations undergoing significant diurnal and seasonal variations. The peak concentration are observed at around mid-day (up to 35 nb) but the O3 concentration generally drops to zero level in the early evening and remains unchanged until mid-morning. Monthly-averaged daily 1-h average concentrations are generally small (4-13 nb) and decrease continually from the early part of the year to the end. Frequently, varying local weather conditions seem to influence the O3 concentrations.