| Summary: | 2019 Living Planet Symposium, 13-17 May 2019, Milan, Italy As a direct response to the Polar Expert Group recommendations for sea ice concentration and high latitude SST’s, EU and ESA have initiated phase A studies for a low frequency high spatial and temporal resolution polar orbiting satellite microwave radiometer in preparation for the Expansion phase of the Copernicus Space Component from 2025: the Copernicus Imaging Microwave Radiometer (CIMR). Compared to the existing and planned Passive Microwave Radiometers (SSMIS, MWRI, AMSR2,.) CIMR will have significantly higher spatial resolution and for one of the two primary geophysical variables: sea ice concentration (SIC) it will have high resolution and very low noise at the same time. These two things are trade-offs with current radiometers. The second primary parameter sea surface temperature (SST) will significantly increase coverage at high latitudes because of the microwave cloud penetrating capabilities. Using simulated brightness temperature (Tb) datasets over snow covered sea ice (SIC=100%) the sensitivity of SIC algorithms each using CIMR channels have been investigated. The simulated Tb dataset has been generated using a combination of a column thermodynamical model and an emission model. We then know the truth, which is 100% SIC, and noise is defined as variability near this reference point. In general, the sources of geophysical noise are: 1) surface emissivity and effective temperature variations, and 2) atmospheric influence on the measured radiances and how these propagate in different SIC algorithms. The goal is to identify SIC algorithms where the combination of CIMR channels is minimizing the geophysical noise or alternatively find algorithms with low sensitivity to noise sources that we cannot correct for. Spatial resolution is a strong requirement in SIC applications and spatial resolution varies with electromagnetic frequency. Therefore we compare the geophysical SIC noise for each algorithm with the representativeness uncertainty using a ...
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