Ozone Observation And Correction Of Ground-Based Total Ozone Retrieval Algorithm At Kunming

Based on the ozone sounding experiments made at Kunming during a one-year period (November 2013 to April 2015), and focus on the correction of ground-based total ozone retrieval algorithm, the performance of Microwave Limb Sounder (MLS) and Atmospheric Infrared Sounder (AIRS) ozone profile was evaluated. Then we researched the effect of approximate calculation of ozone air mass factor (AMF) on the total ozone measurement. Brewer total SO2 data was corrected to study the influence of SO2 on Dobson spectrophotometer total ozone measurement. Application of four different absorption cross sections in total ozone retrieval was evaluated. Finally the comprehensive approach was presented to correct total ozone data measured by Dobson and Brewer spectrophotometer.The result shows:(1) the quality of MLS version 4.2 ozone profile is better than version 3.3 in troposphere, but it has a large positive bias (about (80.5±65.1)%) at 82.5 hPa. AIRS ozone products can not correctly describe the distribution and change of ozone in troposphere and low-stratosphere. (2) when using ozonesonde data to calculate ozone effective height and temperature, the error can be reduced by supplement of sateIlite profile to sounding data.(3) SO2 concentration is mainly below 60 ?g/m3, the peak value appears during 9 to 10 o'clock, diurnal variation is affected by air pollution emission, solar radiation and development situation of boundary layer. (4) The accuracy of Brewer total column SO2 was improved when using near ground SO2 concentration data to correct Brewer SO2. (5) For large zenith angles (?>60°), sphericity effects and atmospheric refraction cause the error in Brewer or Dobson approximation to become increasingly large, AMF is sensitive to ozone-layer height that the lower the ozone-layer, the higher the value of AMF. (6) SO2 absorption coefficient ??AD is 1.843, moreover, the presence of SO2 leads to higher amount of Dobson ozone than the actual values.On the other hand, the effect of SO2 on Dobson total ozone is reduced due to the decrease of total SO2, but it should still be taken into account during a high-pollution period.(7) the systematic annual differences between Brewer and Dobson instruments are due to the different temperature dependence in the instruments' ozone retrieval algorithm, the temperature dependence of Brewer instrument is small than Dobson instrument. Total ozone column (TOC) retrieval algorithm is sensitive to the choice of ozone cross-section data sets:with the application of the SAC cross-section, the difference between Brewer and Dobson data sets vanish, whereas using those of BPQ, DBM and SER produces differences of about 2.92%,-2.57% and-1.83%. (8) The Brewer and Dobson instrument results agree best after correction by using the comprehensive approach. At a low or middle-latitude observation station where the air is clean, the correction is mostly affected by the temperature-dependent ozone absorption coefficient which contributes 57.9?91.2%.