DOI: 10.5281/zenodo.7886426
title: Data accompanying "Summer drought weakens land surface cooling of tundra vegetation"

description: This dataset contains the spatial and meteorological data underlying the statistical analysis in: <em>Rietze et al. (in press) - Summer drought weakens land surface cooling by tundra vegetation</em> All code to preprocess, analyze and visualize this data can be found under https://github.com/nrietze/ArcticDroughtPaper. This dataset contains three major components: The drone-derived mosaics of multispectral, RGB, and thermal imagery. The training polygons used for the land cover classification. Meteorological and micrometeorological observations used in the analysis and descriptions of flight conditions. <strong>Folder structure:</strong> <pre><code class="language-bash">└───data ├───landcover ├───mosaics ├───shapefiles └───tables ├───intermediate └───results</code></pre> Clone the Github repository before downloading this data and insert the contents of this dataset into the empty "data" folder from the Github repo. <strong>Cite as:</strong> Rietze, Nils, Assmann, Jakob J., Damm, Alexander, Naegeli, Kathrin, Karsanaev, Sergey V., Maximov, Trofim C.,Plekhanova, Elena, Schaepman-Strub, Gabriela. <em>(in press</em>). Summer drought weakens land surface cooling of tundra vegetation. <strong>Abstract (from manuscript):</strong> Siberia experienced a prolonged heat wave in the spring of 2020, resulting in extreme summer drought and major wildfires in the North Eastern Siberian lowland tundra. In the Arctic tundra, plants play a key role in regulating the summer land surface energy budget by contributing to land surface cooling through evapotranspiration. Yet we know little about how drought conditions impact plant-mediated land surface cooling by tundra plant communities, and related positive feedback to the high air temperatures. Here we used high-resolution land surface temperature and vegetation maps based on drone imagery to determine the impact of the extreme summer drought in 2020 on land surface cooling in the lowland tundra of North-Eastern Siberia. We found strong differences in land surface cooling among plant communities in the drought year 2020 and the reference year 2021. Further, we observed a decrease in the normalized land surface cooling between the two years using the water deficit index (WDI) across all plant communities during the drought year. This shift indicates an energy budget regime dominated by sensible heat fluxes, contributing to land surface warming. Overall, our findings suggest significant variation in land surface cooling among common Arctic plant communities in the North-Eastern Siberian lowland tundra and a pronounced effect of drought on all community types. Based on our results we suggest accounting for tundra plant communities if we want to accurately predict the impacts and consequences of droughts on land surface cooling and energy flux related processes such as permafrost thaw and wildfires. <strong>Acknowledgements (from manuscript):</strong> N.R. was supported through the TRISHNA Science and Electronics Contribution (T-SEC), an ESA PRODEX project (contract no. 4000133711). Drone data acquisition was supported by the University Research Priority Program on Global Change and Biodiversity of the University of Zurich and by the Swiss National Science Foundation (grant no. 178753). We would like to thank Geert Hensgens of VU Amsterdam for sharing the flux tower data at the research site with us.