Melt pond fractions derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) and its corresponding sea ice concentration data set are valuable sources for multi-ple applications in climate sciences. In this case study, melt pond fractions are used to quantify the uncertainties in sea ice concentration data derived from passive microwave im-agery from Advanced Microwave Scanning Radiometer for EOS (AMSR-E) with different retrieval methods. For the test area of the Canadian Archipelago, we found that all AMSR-E algorithms are clearly underestimating MODIS sea ice con-centration by around 20-30% during the occurrence of a high melt pond fraction of 50% in mid-June 2011.