ALBERT

Description: Thematic Open Access data portals foster and support an open data culture in order to reduce knowledge gaps and data uncertainty. Here we present the Arctic Permafrost Geospatial Center (APGC), which provides open access, high quality spatial data in the field of permafrost research. The distribution and easy access of a wide range of permafrost-related data products supports multi-scale and interdisciplinary analysis of combined field, remote sensing and modelling data. The APGC mission is to provide data that is of high usability, significance and impact, and to facilitate data discovery, data view and supports metadata documentation and exchange via the APGC data catalogue at https://apgc.awi.de/. The catalogue structure can host data models of varying themes, formats, and spatial and temporal extents. Data can be searched by interactively selecting locations on a base map and by many predefined metadata filters. Data can be downloaded directly through a link to the publishing data repository such as PANGAEA. The Catalogue is based on the open source CKAN catalogue architecture, which allows on-the-fly access to catalogued data in QGIS. The APGC currently features over 200 selected datasets from projects such as ERC PETA-CARB, ESA GlobPermafrost, and others. Data products provide information about surface and subsurface permafrost characteristics in the Arctic, Antarctica, or mountain permafrost areas, e.g., soil temperatures, soil carbon, ground ice, land cover, vegetation, periglacial landforms, subsidence and more. Collections of datasets allow users to easily get an overview of the spatial distributions of datasets or their availability in different formats. An additional WebGIS application allows users to explore most of the data interactively (https://maps.awi.de). Data submissions are evaluated according to the following access criteria: permafrost focus, broader significance and impact, open access, high quality, and available metadata.

Description: Uncertainty in carbon cycling in terrestrial ecosystems contributes to overall uncertainty in Earth System Models. In particular, polar terrestrial ecosystems are understudied. Here, we focus on optical and radar remote sensing approaches to understand above-ground carbon dynamics related to vegetation as primary producers in tundra permafrost landscapes. In the ongoing Russian-German research cooperation and joint field expeditions we evaluate the applicability of remote sensing for assessing vegetation stocks and short-term fluxes in the Lena River Delta in the Siberian Arctic. New spaceborne satellite missions such as Sentinel-1, Sentinel-2 and ESA Data User Element DUE Permafrost provide useful services and data for this investigation. i) We evaluated and ground-truthed circumarctic-harmonized geospatial products of land cover and vegetation height from the ESA GlobPermafrost program for the Lena Delta region. The remote sensing products were derived from radar Sentinel-1 and optical Sentinel-2 satellite data. They are findable in the Arctic Permafrost Spatial Center (APGC) (apgc.awi.de) and are published under 10.1594/PANGAEA.897916, [Titel anhand dieser DOI in Citavi-Projekt übernehmen] and 10.1594/PANGAEA.897045 [Titel anhand dieser DOI in Citavi-Projekt übernehmen] . ii) We classified land cover using Sentinel-2 data based on in-situ vegetation data and optimized on biomass and wetness regimes. iii) We investigated the applicability of different land cover products for upscaling in-situ field-based biomass estimates to landscape-scale above-ground vegetation carbon stocks. iv) We investigated how disturbances enhance above-ground vegetation carbon cycling using in-situ data on vegetation community, biomass, and stand age and including remote sensing observations. Our research suggests that subarctic land cover needs to show biomass and moisture regimes to be applicable. Sentinel-1 and Sentinel-2 satellite missions provide adequate spatial high resolution to upscale vegetation communities and biomass in permafrost tundra landscapes. Biomass is providing the magnitude of the carbon flux, whereas stand age is irreplaceable to provide the cycle rate. High disturbance regimes such as floodplains, valleys, and other areas of thermo-erosion are linked to high and rapid carbon fluxes compared to low disturbance on Yedoma upland tundra and holocene terraces with polygonal tundra.