Evaluation of Total Column Ozone derived from CAMS against AIRS datasets across the Indian subcontinent

Present work examined the spatio-temporal variability of total column ozone (TCO) using the Copernicus Atmospheric Monitoring Service (CAMS) reanalysis dataset (2005–2020) over the Indian subcontinent. TCO data from CAMS is evaluated against the TCO from the Atmospheric Infrared Sounder (AIRS) satellite dataset using descriptive statistical analysis. CAMS TCO shows better agreement with AIRS TCO with a correlation coefficient ranging from 0.72 to 0.83 across different regions of Indian subcontinent. From the seasonal variation of TCO, an increasing shift of TCO is observed from low (Southern India) to high (North-West & Indo-Gangetic Plains) latitudinal regions during pre-monsoon and monsoon seasons ranging from 280 to 310 DU. From the seasonal evaluation of CAMS TCO against AIRS TCO a strong correlation ranges from 0.85 to 0.92 is observed during the winter (DJF) and pre-monsoon (MAM) seasons, followed by the monsoon (JJAS) and post-monsoon (ON) seasons. Monthly evaluation of CAMS TCO with AIRS TCO, shows that CAMS TCO underestimates in comparison to AIRS TCO during all the monsoon and post-monsoon months over the Indian sub-continent. • Higher TCO are prevalent over Indo-Gangetic Plains and North-West India, while lower values in Southern and Central India. • CAMS TCO shows better resemblance and agreement with the AIRS TCO. • Seasonal variations in TCO follow photochemical processes that peak during the warmer months with maximum solar radiation.