Assessment And Evaluation On The Chinese-remade Electrochemical Concentration Cell (C-ECC) Ozonesondes

The thesis focuses the studies of performance testing on Chinese-made electrochemical concentration cell (C-ECC) ozonesondes. The detailed tests including the performance of self-developed hypobaric chamber, pump efficiency factor measurements in the lower atmospheric pressure conditions simulated by the hypobaric chamber, and the resulted pump efficiency correction factors are presented. The influences of SO2 and NO2 on the electrochemical reactions between ozone and KI solution, and the response time of the ECC to the ozone concentration changes are also determined. The measured pump correction factors are applied for correcting ozone data measured by the C-ECC ozonesonde in the atmosphere. Besides, this thesis also describes C-ECC ozonesonde’s technical features, exploring the methods of residual ozone calculations influencing ozonesonde integrated total ozone. The conclusions of this thesis can be drawn as follows:(1) In order to verify whether the self-developed hypobaric chamber satisfies ozonesonde pump efficiency measurement environment or not, we tested and analyzed its parameters such as pressure range, dynamic pressure response characteristics, static pressure response characteristics leakage rate and bias of pressure determination. The results confirm that the hypobaric chamber can be applied to simulate low pressure environment in the indoor condition, satisfying or even exceeding the design standard.(2) Pump efficiency test methods has been designed in laboratory. We tested and analyzed pump efficiency of C-ECC ozonesonde at different pressure levels ranging from 1000 hPa-5 hPa in the hypobaric chamber. These pump efficiency correction factors had been used for correcting the C-ECC ozone profiles.(3) Methods for testing the interferences from the pollutant gases, SO2 and NO2, on the C-ECC measurement are quantitatively tested and analyzed, and the response time of the C-ECC had been measured and compared with those of imported ECC ozonesonde.(4) We contrastively analyzed different methods that were used for computing residual ozone when balloon blows up at different altitude and latitude, and we also investigated the MLS difference between actual measurement and the satellite-derived global zonal band mean. Therefore, we established a suitable method to compute total ozone on the basis of the ECC ozonesonde profiles. Total ozone is also as one of important parameters to evaluate the C-ECC ozone sonde profiles.(5) Comparative experiments had been arranged in Beijing and Yangjiang respectively. C-ECC and imported ECC ozonesonde were simultaneously elevated by a balloon for measuring ozone vertical profiles. In order to verify the validation of the pump efficiency measured in laboratory, we compared ozone profiles from the two kinds of ECC ozonesonde. At the same time, the total ozone measured by Brewer#074 was used also as a reference of the ozonesondes consistency.The results show that ozone profiles have a good consistency between C-ECC imported ECC ozonesonde. In 40-10 hPa, C-ECC data is 2-3 mPa lower than that of the imported ECC, and the difference reduces to only 0.5 mPa after the pump efficiency correction factors has been applied to the C-ECC. C-ECC occasionally overestimates ozone at 70 hPa or at higher pressure, but it tends to be more agreeable with the imported ECC ozonesonde profiles when pressure is 10 hPa or lower. Although the pump efficiency correction factor is not uniform for each C-ECC ozonesonde, it does improve the consistence of column ozone amount from the tropopause to 26 km where more than 40% atmospheric ozone resides. The column ozone would be also overestimated at 28-31 km with the correction factors. Overall, the C-ECC ozonesonde has a good consistency with the imported ECC even though its stability in the performance needs to be improved in the future.