Total column ozone retrieval using insat-3d sounder in the tropics: A simulation study

Abstract

The present study examines the potential of infrared sounder observations from Indian geostationary satellite INSAT-3D for the estimation of total column integrated ozone over the tropical Indian region. A dataset with diverse profiles was used to create training and testing datasets using forward simulations from a radiative transfer model for infrared sounder channels. A study was carried out for the standard tropical atmospheric profile to examine the sensitivity of ozone band radiance corresponding to the atmospheric temperature, water vapour, and ozone mixing ratios at different atmospheric pressure levels. Further, statistical retrieval technique has been used for the total column ozone estimation using two different approaches: (i) ozone channel observation along with the a-priori estimate of temperature and water vapour profile and (ii) only sounder channels observations. The accuracy of the retrieval algorithms was examined for different errors in the atmospheric profiles for the method (i) and different sensor noise specification for the method (ii). This study has shown that accurate temperature information is very important for ozone estimation and lower instrument noise results in better ozone estimates.