Midwinter thaw events over Greenland derived from Seawinds QuikScat 2000-2008

Scatterometer data acquired in Ku-band from the QuikSCAT satellite have been used to identify midwinter melt events over Greenland. The focus was set on winter months (November-March) 2000 to 2008. Several approaches were examined for their capability of detecting thaw events. In the first case the change of the backscatter coefficient sigma0 based on a three-day moving window was used. In the second case the difference between two consecutive days was used. Two types of parameterization have been investigated for both cases: a constant threshold of 1.5 dB (Approach I and III) and a location specific noise level (Approach II and IV). Thaw events were detected for all winters, however, the spatially largest extent was found during late November in 2005 in case of all approaches. The dataset (csv files) includes the results from all four approaches. Grid spacing is 10km (pre-processed based on Bartsch et al. 2007). The following values are provided for each detected event: grid point ID (GP_NAME), latitude, longitude, date, depending on the approach a three day average difference or a day to day difference of sigma0 and if used (Approach II and IV) the location specific noise multiplied by three. Shape files are provided for the three largest detected events in addition: 26.11.-30.11.2005, 17.11.-21.11.2007 and 01.-04.11.2008. No Data value is -9999. Algorithm details and overview maps are provided in Freund (2017).