Antarctic passive microwave Kmeans derived surface melt days, 1979-2020

This dataset contains the total number of days per year with meltwater present at the surface across the Antarctic ice sheet and surrounding ice shelves derived from passive microwave satellite observations for each melt year from 1979/80 to 2019/20. This data comes from daily and near-daily SMMR, SSM/I, and SSMIS results at 25 km resolution at 19 GHz horizontal polarization. Each melt year starts on July 1 and ends June 30. The melt detection algorithm is described in Johnson and others (2020) and uses KMeans clustering analysis of the annual brightness temperature time series on each pixel to detect melt for that pixel and year.