Observational Analysis of Surface O3、NOX and SO2 in China

From August 1994 to August 1995, the continuous in-site measurements of surface O3, NOX and SO2 have been made in three sites of China which are Lin’an, Longfengshan background stations, and Waliguan baseline observatory. The preliminary analysis of the data indicates that the average concentration, monthly and diurnal change of surface O3 mainly depend on geographic environment, sea level and weather conditions. During the priods of measurement, the average concentrations of surface O3 are 34.8×10-9 in Longfengshan, 39.1×10-9 in Lin’an and 49.3×10-9 in Waliguan, respectively. The monthly average concentrations of surface O3 are quite different in these sites, in Lin’an and Longfengshan, O3 concentrations show lower in December and January, and in June and July, respectively, and higher from the end of October to early November, while in Waliguan, the monthly variation of O3 concentration is much smaller, the lowest value in December, and the highest in June. The diurnal variation of surface O3 concentration shows an obvious diurnal cycle with a maximum in the afternoon and a minimum in the early morning in Longfengshan and Lin’an, but with a small diurnal variation in Waliguan. The distributions of NOX and SO2 show an obvious local characteristies, the average concentrations are 2.7×10-9 (NOX) and 0.7×10-9 (SO2), 8.1×10-9 (NOX) and 16.1×10-9 (SO2), 0.04×10-9 (NO2) and 0.15×10-9 (SO2), respectively in Longfengshan, Lin’an and Waliguan stations