A New Near Real Time Sea Ice Concentration Algorithm for OSI SAF

The retrieval of sea ice concentration (SIC) using passive microwave satellite sensors has become a well-established field over several decades. Various algorithms employing slightly different approaches, such as utilizing diverse microwave satellite channels with the ability to combine frequencies and polarizations, have been tested in previous studies. This paper further explores the possibility of using the Radiative Transfer Model (RTM) to remove atmospheric effects on Brightness Temperature (TB) to improve SIC retrievals. This study specifically falls within the framework of the OSI SAF Near Real Time (NRT) SIC products, actively developed and maintained by the Danish Meteorological Institute (DMI). The findings indicated the feasibility of using the RTTOV package of NWP SAF for the atmospheric corrections. The RTTOV-based atmospheric correction could remove warm TB signals over the ocean due to atmospheric effects, resulting in the removal of false sea ice signatures without using empirical filters. The proposed atmospheric correction scheme is straightforward to adopt for the upcoming passive microwave sensors without intensive sensor-specific calibration (e.g., EUMETSAT’s MWI, JAXA’s AMSR-3, and ESA’s CIMR).