ALBERT

Description: Particles sinking out of the euphotic zone are important vehicles of carbon export from the surface ocean. Most of the particles produce heavier aggregates by coagulating with each other before they sink. We implemented an aggregation model into the biogeochemical model of Regional Oceanic Modelling System (ROMS) to simulate the distribution of particles in the water column and their downward transport in the Northwest African upwelling region. Accompanying settling chamber, sediment trap and particle camera measurements provide data for model validation. In situ aggregate settling velocities measured by the settling chamber were around 55 m d(-1). Aggregate sizes recorded by the particle camera hardly exceeded I mm. The model is based on a continuous size spectrum of aggregates, characterised by the prognostic aggregate mass and aggregate number concentration. Phytoplankton and detritus make up the aggregation pool, which has an averaged, prognostic and size dependent sinking. Model experiments were performed with dense and porous approximations of aggregates with varying maximum aggregate size and stickiness as well as with the inclusion of a disaggregation term. Similar surface productivity in all experiments has been generated in order to find the best combination of parameters that produce measured deep water fluxes. Although the experiments failed to represent surface particle number spectra, in the deep water some of them gave very similar slope and spectrum range as the particle camera observations. Particle fluxes at the mesotrophic sediment trap site off Cape Blanc (CB) have been successfully reproduced by the porous experiment with disaggregation term when particle remineralisation rate was 0.2 d(-1). The aggregation-disaggregation model improves the prediction capability of the original biogeochemical model significantly by giving much better estimates of fluxes for both upper and lower trap. The results also point to the need for more studies to enhance our knowledge on particle decay and its variation and to the role that stickiness play in the distribution of vertical fluxes

Description: Permafrost regions are highly sensitive to climate change. Bringing research data and metadata from diverse sources together and visualising them within a publicly available worldwide system would have an enormous impact on data accessibility and availability and would significantly promote scientific work. The CarboPerm WebGIS, a case study focusing on the Lena River Delta in the Laptev Sea Region (Siberia), shows how a WebGIS infrastructure can support scientific work, data management, data visualisation, and data publication. CarboPerm is an interdisciplinary German project with Russian cooperation, investigating the formation, turnover and release of carbon in Siberian permafrost landscapes. There, the Lena River formed the largest delta in the Arctic and is place of long-term Russian-German scientific cooperation in permafrost research. The CarboPerm WebGIS is being set up to visualise and emphasise the spatial context of local samples, measurements, and analyses versus the thematic background information (e.g., geomorphology, pedology, geology and vegetation), using the WebGIS infrastructure “maps@awi” at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI). The CarboPerm WebGIS database includes historical data from long-term Russian-German cooperation and recent field campaigns as well as environmental datasets that are freely available via the internet or research data repositories.

Description: Permafrost-Landschaften reagieren sehr sensibel auf den Klimawandel. Die Synthese von Forschungsdaten und Metadaten über diese Gebiete und deren Visualisierung in einem interoperablen, weltweit zugänglichen System ist von hohem Nutzen für Wissenschaft und Gesellschaft. Innerhalb des Permafrost-Forschungsprojektes CarboPerm wird für das Lena- Delta und die Laptevmeer-Region ein WebGIS-Projekt entwickelt, welches die wissenschaftliche Forschertätigkeit durch Datenmanagement, Datenvisualisierung und Datenpublikation unterstützt. CarboPerm ist ein interdisziplinäres deutsch-russisches Kooperationsprojekt, das die Bildung, den Umsatz und die Freisetzung von Kohlenstoff in sibirischen Permafrost-Landschaften untersucht. Der Fluss Lena hat das größte Delta in der Arktis ausgebildet und ist gleichzeitig ein Kerngebiet langjähriger russisch-deutscher Kooperation in der Permafrost-Forschung. Das CarboPerm WebGIS wurde ins Leben gerufen, um den räumlichen Bezug von lokalen Probennahmen, Messergebnissen und Analysen mit thematischen Hintergrundinformationen, wie z.B. Geomorphologie, Pedologie, Geologie und Vegetation zu visualisieren. Die CarboPerm-WebGIS-Datenbank entstand unter Nutzung der WebGIS-Infrastruktur „maps@awi“ am Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI). Sie beinhaltet sowohl historische Daten aus der langjährigen russisch-deutschen Kooperation als auch von aktuellen Geländekampagnen, sowie umweltrelevante räumliche Datensätze, die aus öffentlich zugänglichen Datenquellen und Daten-Repositorien stammen.

Description: In this opinion paper, we, a group of scientists from environmental-, geo-, ocean- and information science, argue visual data exploration should become a common analytics approach in Earth system science due to its potential for analysis and interpretation of large and complex spatio-temporal data. We discuss the challenges that appear such as synthesis of heterogeneous data from various sources, reducing the amount of information and facilitating multidisciplinary, collaborative research. We argue that to fully exploit the potential of visual data exploration, several bottlenecks and challenges have to be addressed: providing an efficient data management and an integrated modular workflow, developing and applying suitable visual exploration concepts and methods with the help of effective and tailored tools as well as generating and raising the awareness of visual data exploration and education. We are convinced visual data exploration is worth the effort since it significantly facilitates insight into environmental data and derivation of knowledge from it.

Description: Permafrost is an important component of the Cryosphere, which is affected by rapid warming of the Arctic. The degradation and thaw of permafrost in vertical as well as lateral directions results in a reduction of permafrost in high latitudes and high altitudes. Since permafrost affects the ecosystem conditions of the about 23 million square kilometer large permafrost region, its loss has strong effects on hydrology, geomorphology, biogeochemistry, and biota. In addition, permafrost soils store about 1500 Gt of organic carbon, about twice the amount currently in the atmosphere and hence changes in permafrost will likely have impacts well beyond local scales. Remote sensing has become an essential tool for quantitatively detecting and monitoring changes in permafrost and associated landscapes. The European Space Agency (ESA) has supported permafrost-focused remote sensing activities in two recent projects, ESA DUE Permafrost (2009-2012) and the ESA GlobPermafrost (2016-2019; http://www.globpermafrost.info). The first ESA DUE Permafrost project with spatial overage of the Northern Hemisphere developed, validated and implemented Earth Observation to support research communities and international organizations in their work on better understanding permafrost characteristics and dynamics. Now, the GlobPermafrost project expands on this successful approach by including both polar hemispheres as well as mountain permafrost regions. Products in the new project will cover different aspects of permafrost by integrating in situ measurements of subsurface properties and surface properties, Earth Observation, and modelling. Currently, the GlobPermafrost team is creating prototype remote sensing derived datasets for defined product and user groups. Selected users will be able to access the usability and validity of the products and provide feedback back to the GlobPermafrost team. The feedback from the Users Groups will be integrated into optimized remote sensing products until they have achieved a final state. To bring the resulting data products closer to the permafrost user communities, the Permafrost Information System (PerSys) has been conceptualized as an Open Access geospatial data dissemination and visualization portal for Earth Observation, i.e. remote sensing derived datasets produced within the GlobPermafrost project. The prototype and final remote sensing products and their metadata will be visualized in the PerSys WebGIS, described and searchable via the PerSys Data Catalogue. The WebGIS visualization is managed via the AWI WebGIS Infrastructure maps@awi (http://maps.awi.de) relying on OGC-standardized Web Mapping Service (WMS) and Web Feature Service (WFS) technologies for data display and visualization. The PerSys WebGIS projects allow visualisation of raster and vector products such as land cover classification, Landsat multispectral index trend datasets, lake and wetland extents, InSAR-based land surface deformation maps, rock glacier velocity fields, spatially distributed permafrost model outputs, and land surface temperature datasets. Each of these WebGIS projects is adapted to the spatial scale of the specific products, ranging from local to hemispherical coverage. The PerSys Data Catalogue will provide the metadata and the access to all mature-state and final-state GlobPermafrost products. PerSys can be accessed through the GlobPermafrost project webpage. PerSys is also a core component of the Arctic Permafrost Geospatial Centre (APGC), a geodata portal for permafrost launched within the framework of the ERC PETA-CARB project at the Alfred-Wegener-Institut Helmholtz Zentrum für Polar and Meeresforschung. The APGC framework features a range of permafrost-specific geospatial data projects, including PerSys, and will allow searching for project-specific geospatial data by tags, keywords, data type and format, licence type, or by location. PerSys will be launched within APGC in early 2017. In addition, the Open Access data library PANGAEA as a certified ICSU member will serve as permanent archive for the GlobPermafrost final products, providing permanent Digital Object Identifiers (DOIs) for each dataset archived. The ESA DUE Permafrost final product data set is already published under DOI doi:10.1594/PANGAEA.780111. The final GlobPermafrost remote sensing products published in PANGAEA will remain visualised in the PerSys WebGIS and catalogued and made searchable and accessible via the PerSys Data Catalogue.