Pan-Arctic lake area time series (2017-2021)

### Access

Data are available for download at [http://arcticdata.io/data/10.18739/A28G8FK10](http://arcticdata.io/data/10.18739/A28G8FK10)

To download all files in the command line, run the following command in a terminal:

`wget -r -np -nH --cut-dirs=3 -R '\?C=' -R robots.txt https://arcticdata.io/data/10.18739/A28G8FK10`

To download only a subdirectory of the archived files, add the subdirectory to the end of the URL above.

### Overview

Lake area for permanent and seasonal in the Arctic were derived from Landsat satellite imagery from 1984-2021 using machine learning. Data was collected for lakes with a maximum extent larger than one hectare, buffered by 30 meters, within four discontiguous transects across the Arctic region at latitudes greater than 60 degrees North. This region covers large parts of the northern permafrost terrain. This annual lake area data was merged with lake size trend attributes derived from the years 2011-2020. Lake area change rates were normalized by area and/or perimeter. The lake extraction methodology is based on Nitze et al, 2017 and 2018. This dataset is version 2.0. You can find version 1.0, related to Nitze et al. 2018 here: https://apgc.awi.de/dataset/hot-t1-prd-lake-ls-1999-2014 https://apgc.awi.de/dataset/hot-t2-prd-lake-ls-1999-2014 https://apgc.awi.de/dataset/hot-t3-prd-lake-ls-1999-2014 https://apgc.awi.de/dataset/hot-t4-prd-lake-ls-1999-2014

Data files were merged, and the annual permanent and seasonal water data for 2017-2021, a subset of the available years, was fed into the Permafrost Discovery Gateway visualization workflow. This workflow cleaned, standardized, and visualized the data and output two Tile Matrix Sets per year. One Tile Matrix Set is the data in the form of GeoPackages, or staged tiles, and the other Tile Matrix Set is the staged tiles in the form of GeoTIFF tiles. The highest resolution tiles were resampled to produce GeoTIFFs for lower resolutions. In the future, this dataset will be expanded for annual data for 1984-2021. This visualized data will be published on the Permafrost Discovery Gateway portal: https://arcticdata.io/catalog/portals/permafrost/Imagery-Viewer

Data limitations in use: This data is part of an initial release of the pan-Arctic data product for lake area and size trends, and it is expected that there are constraints on its accuracy and completeness. Users are encouraged to provide feedback regarding how they use this data and issues they encounter during post-processing. Please reach out to the dataset contact or a member of the Permafrost Discovery Gateway team via [e-mail].