The Measurement Of Ozone Profiles And Ultraviolet Radiation And Validation Studies With Satellite-derived Products

Based on the ozone profiles observed by Umkehr and ozone-sonde at Waliguan(Xining),Longfenshan,Lin’an, Kunming, Zhongshan and several stations of WOUDC, this thesis uses spline interpolation method to process the satellite-derived ozone profiles(NOAA-SBUV, FY-3 SBUS, Aura-MLS) as well as ground- and ozone-sonde based data, then the validation study mainly focus on the SBUV and SBUS satellite ozone profiles is presented by the comparisons between satellite vs.ground-based, satellite vs. satellite and satellite vs.ozone-sonde at the approximate temporal-spatial scales.The results show that the concentration relative differences(RD) between SBUV and Umkehr ozone profiles occur at different layers: The time series comparisons show an good agreement between satellite and ground-based ozone profiles. The results may vary slightly from different stations or altitude. The prior ozone profiles used in satellite algorithm is derived from the zonal mean ozone profile, and they may result in errors. Umkehr algorithm underestimate ozone amount in lower stratosphere. Seasonal changes and instrument operating environment may also influence the results of comparison. Algorithm and the measurement themselves may influence the results when different satellite instruments compare with each other. For example, the signal of QBO is very clear when comparing SBUS with MLS. The relative differences between satellite and ozone-sonde are mostly within ±20%,but some are larger. Some comparisons in the tropical is generally consistent to within zoneSecondly, the thesis presents the observational study of ultraviolet radiation at Dangxiong, Tuotuhe, Lhasa, Waliguan. The results show that the key factors modifying the ultraviolet radiation over the Tibetan region are SZA and cloud. The “ozone valley” enhance 12% summer surface UVI as compared to that at the similar latitudes but over plain regions. As compared with UVI measured at Lhasa(91.13°E, 29.67°N, 3650 m a.s.l), Tutuhe(92.43°E, 34.22°N, 4500 m a.s.l) and Waliguan(100.90°E, 36.29°N,3810 m a.s.l), the difference of site-altitude is a key influencing factor of the UVB. Under the same SZA conditions, the summer UVB at Lhasa is 7-10% higher than that at Waliguan due to the southern thinner ozone layer caused by the “ozone valley”. Comparison with satellite-derived product show that, averagely, the OMI-UVB is 80% higher than the ground-based values at Dangxiong but with only 8.6% higher in the cloud-free comparisons. The OMI-UVB are all above 65% higher than those ground-based measurements at the other 3 sites but their cloud-free values are only 13%, 9% and 50% higher respectively at Tutuhe, Waliguan and Lhasa. Clouds and geographical mismatches between the satellite pixel and fixed ground –based observation site are speculated to be the main factors of higher space-based UVB values, particularly over Lhasa. As the ground-based UVB was high(UVI>14), the coincident space-based UVB is generally 3% lower at Dangxion owning to the broken clouds strengthening the in-situ radiation.