Retrieval of atmospheric water vapor and temperature profiles over Antarctica from satellite microwave observations using an iterative approach

Retrieving atmospheric water vapor and temperature profiles over land using microwave radiometry is challenging due to uncertainties in estimating surface emissions. To address this, we developed an approach that couples the atmospheric retrieval algorithm with the surface emission estimation in an iterative loop. Using sounding channels from Ka- to G-band on the Advanced Technology Microwave Sounder (ATMS), we retrieved temperature and humidity profiles across the Antarctic region throughout the year 2016. The atmospheric profiles are updated in each iteration and used in the following step to refine the surface emissivity. This process continues until the atmospheric solution converges. The main innovation is the integration of surface and atmospheric retrievals, which improves overall accuracy. We validated our results against in situ radiosonde data. The algorithm accurately retrieved temperature profiles, along with surface emissivity across 23–165 GHz, and successfully detected ice sheet meltings. While it captured water vapor variability, accurate absolute humidity values still require an independent surface emissivity retrieval using additional observations.