Residual Ozone and Ozonesonde Correction Factor over Different Sites of Chinaormalsize

Residual ozone Ω_res is the integrated column ozone from the balloon bursting altitude, which is generally from 30~5hPa, to the top of atmosphere. The ozonesonde correction factor C_ref is the ratio of total column ozone Ω, which is precisely observed by ground or spacebased spectrophotometer, to the summery of Ω_ecc and Ω_res. Ω_ecc is the integrated ozonesonde data from ground to the balloon bursting altitude. C_ref is applied to assess and correct the stratospheric ozonesonde data with the well qualified Ω. Based on the sporadic Electrochemical Concentration Cell (ECC) ozonesonde data observed at different sites of China, Ω_res deduced by the Constant Mixing Ratio (CMR) and satellite zonal mean (including SBUV and MLS tables) are presented, and the impact of Ω_res on C_ref is investigated. The contributions of ozone vertical distribution to C_ref are also analyzed, and appropriate method to quantify Ω_res is proposed through the C_ref comparisons. Ω_res deduced by CMR method is sensitive to the balloon-bursting altitude, and is frequently overestimated. As a result, C_ref is generally less than 100%. Ω_res deduced by the satellite zonal mean method is not sensitive to the balloon-bursting altitude. However, C_ref is lower than about -10DU in two regions. One region is in east of China, such as Longfengshan in Heilongjiang province and Beijing, which is high total column ozone; the other region is Tibetan plateau and other low latitude districts including Hong Kong, which is low column ozone. The satellite zonally underestimated Ω_res reflects the longitude dependence of real atmospheric ozone over China. The tropospheric column ozone Ω_tro from the surface to 100hPa, stratospheric column ozone Ω_str from 100 to 10hpa and Ω_res to C_ref account 16%±3.4%, 65%±2.3%, 19%±3.3%, respectively. Therefore, it is necessary to consider the effects from Ω_tro and Ω_res on the evaluation or correction stratospheric ozone measured by ozonesonde if C_ref is used. The satellite zonal mean method is generally recommended, especially the Ω_res obtained when it is very close to the quasi real-time SBUV data. However, as the balloon bursting altitude above 10hPa, the conventional CMR method is also recommended for the two regions including north of east and north in China (winter and summer)-the high total ozone region, and Hong Kong (summer, autumn and winter), Tibetan plateau (summer) -the low total ozone region. It can weaken a system underestimation of C_ref if the satellite deduced Ω_res is used.