Antarctic Arctic Arctic Ocean Arctic aerosol Arctic clouds Arctic coast Arctic radiative budget COVID-19 Chandra–Bhaga basin Fram Strait GLCM Greenland Sea Hopen Island ICESat-2 InSAR MODIS NDVI Ny-Ålesund SAR imaging SIOS SPM Sentinel-1 Sentinel-1 and Sentinel-2 Sentinel-2 Svalbard WorldView-2 active layer aerosol microphysical properties aerosol modification aerosol optical properties