Terra Nova Bay Polynya Evolution by MODIS Imagery during Winter 2003 - 2016

Remote sensing is essential for monitoring polynyas dynamics. On regional scales, passive microwave (PM) radiometers provide useful information about their extent. Their coarse resolution often limits an accurate separation of open water from ice cover. Despite their sensitivity to the presence of clouds, thermal infrared (TIR) Moderate Resolution Imaging Spectroradiometers (MODIS) provide high resolution information (typically 1 Km) at large swath widths, several times per day. In this study we apply a new methodology that combines a sequence of MODIS swath-based scenes to examine the TNB evolution in the winter season during the last 14 years (2003-2016). Results have been validated through the comparison with a huge set of SAR images acquired by ENVISAT, SENTINEL and COSMO-SkyMed satellites. The good agreement with most of the analyzed SAR images demonstrated the potential of this tool for the continuous monitoring of the polynya extent and the consequent estimation of ice production rates. A comparison with TNB polynya extent estimations retrieved by other MODIS and PM based tools has also been carried out and differences discussed. Furthermore, the polynya events identified through our technique have been compared to the katabatic events captured by the automatic weather stations located along the TNB coast, and their interannual variability analyzed.