Variation Of Total Ozone Over China For30Years And Meteorological Factors On Ozone Concentrations Near The Ground

Ozone is an important atmospheric trace gas. The changes of ozone have a significant impact on the global climate and environmental changes. This paper focuses on the temporal and spatial dynamics of total ozone over China from1981with multi-resource remotely sensed data and ground-level monitoring.The results indicate the precision of the total ozone retrieved from SBUV is higher than that from TOMS; the estimated TOMS total ozone has a higher precision at higher latitudes, while OMI total ozone accuracy is better than TOMS at lower latitudes; compared to TOU, OMI total ozone data has greater uncertainty and the retrieval error is bigger than TOU total ozone.The total ozone over China is continuously decreasing. The decreasing speed is lower than that of the whole world and almost the same as that of the northern hemisphere. The total ozone declines by0.11%per year, reaching0.36DU. However, the pace of decreasing slowed down since2000. The total ozone tended to increase from2005.The seasonal variation of total ozone in China shows a sine curve,, the average maximum and the minimum value is about333.36DU and284.54DU, which occurs in March and October respectively. The total ozone of eastern region is higher than that of the western region. The seasonal variation of the southern area and the northern area is almost opposite.We use the data of ground-based observations from Nanjing University of Information Science&Technology, including near-surface to analyze influence of the meteorological conditions to the ozone concentration variation. The results show that the ozone concentration near the ground has a day cyclical fluctuation and a single peak distribution. Maximum values appears in the afternoon around15:00, while at night there exists a low level ozone concentrations, and the lowest value appears around07:00in the morning. Diurnal and seasonal ozone concentrations near the ground increase with the air temperature rising, Compared to air temperature, precipitation, relative humidity have an opposite effect on near-surface ozone concentration. When the wind speed reaches to1.1～3.0m/s, the ozone concentration near the ground maintain a higher value, while the concentration of ozone is smaller if the wind speed is less than1.0m/s. A higher ozone concentration exists in June when the dominant wind direction is south-east or west.