Pan-Arctic surface water (yearly and trend over time) 2000-2021

Surface water change has been documented across the Arctic due to thawing permafrost and changes in the precipitation/evapotranspiration balance. This dataset uses Moderate Resolution Imaging Spectroradiometer (MODIS) data to track changes in surface water across the region over the past two decades. The superfine water index (SWI) is a unitless global water cover index developed specifically for MODIS data and validated in high northern latitudes. Variation in SWI can also track changes in surface water that occur at the sub-MODIS pixel scale (i.e., changes in water bodies smaller a MODIS pixel, ~500 meters (m)). This dataset (1) maps the average July SWI over pan-Arctic for each year of the MODIS record (2000-2021) and (2) maps the trends in July SWI over 2000-2012 (i.e., Sen's slope of the pixel-wise SWI vs. time). The spatial resolution of this dataset is ~500 m. The yearly SWI files are processed for the entire continuous and discontinuous permafrost zone. The trend file is processed for lake-rich regions of the Arctic (i.e., lake coverage greater than 5%), as was published in the Webb et al, 2022 paper.