becoming more frequent and intense. The Arctic Ocean also suffers from this development: The absence of sea ice will lead to more extreme fluctuations in ocean temperatures, with abrupt temperature changes [...] Wegener Institute shows how marine heatwaves will also become much more intense and frequent in the Arctic in the 21st century. With drastic consequences for the ecosystem. The researchers published their

Molecular Sea Ice Ecology Polar oceans are seasonally covered by sea ice with an average size of the continent of North America. Despite harsh conditions therein, sea ice and its lower surface can carry [...] community, typically dominated by Diatoms. Sea ice can provide important primary production to polar oceans via these communities, although they are often very patchy. In times of declining sea ice coverage [...] biodiversity, functions provided by its biota, and the future of sea ice communities in a warming ocean. We address these questions through analyses of total communities, their molecular biodiversity and

Main REcoM references: Schourup-Kristensen, V., Wekerle, C., Wolf-Gladrow, D., Völker, C. (2018): Arctic Ocean biogeochemistry in the high resolution FESOM 1.4-REcoM2 model, Progress in Oceanography, 168, [...] (2014). A skill assessment of the biogeochemical model REcoM2 coupled to the Finite Element Sea Ice-Ocean Model (FESOM 1.3), Geoscientific Model Development, 7 (6), 2769-2802. doi:10.5194/gmd-7-2769-2014 [...] Losch, M. and Wolf-Gladrow, D.A. (2013). Seasonally different carbon flux changes in the Southern Ocean in response to the southern annular mode, Global Biogeochemical Cycles, 27 (4), 1236-1245. doi:10

sea ice models used for? Example of a sea ice model (Graphic: Alfred Wegener Institut) The Arctic areas - ocean even more than land - are difficult to reach, for several winter months not at all. Instruments [...] time. Variability is determined e.g. by air and ocean temperature. The velocity in turn depends on the thickness of the ice, the wind conditions and the ocean current. The changes of the sea ice over time [...] This explains the expression "compute the model forward in time". The area of interest- here the Arctic Ocean is overlaid with a three-dimensional grid. The geometry of this grid can be as simple or complicated

research with an Autonomous Underwater Vehicle: Payload structure and arctic operations. OCEANS - Bergen, 2013 MTS/IEEE, doi:10.1109/OCEANS-Bergen.2013.6608043. Wulff, T., Lehmenhecker, S., Hoge, U. (2010) [...] On their way through the ocean they carry different instruments to measure several parameters from the temperature of the water to the amount of light penetrating the ocean. At the end of a mission the [...] I 115: 253-264. Wulff, U., Wulff, T. (2015). Correcting Navigation Data of Shallow-Diving AUV in Arctic. Sea Technology 56(3): 27-30. Wulff, T., Lehmenhecker, S., Bauerfeind, E., Hoge, U., Shurn, K., Klages

within one year due to the self-discharge of the battery in -1.75°C bottom waters of the deep Arctic Ocean. TRAMPER can be deployed with pin-point accuracy by means of a video-controlled cabled launching [...] crawler for long-term benthic oxygen flux studies in remote deep sea ecosystems , OCEANS 2016 MTS/IEEE Monterey, doi: 10.1109/OCEANS.2016.776121.

the buoyancy and stickiness of floating microplastic particles leading to an export to the deeper ocean and sediments. Meanwhile, scientists and authorities worldwide have recognized the massive accumulation [...] stipend), Sebastian Primpke and Gunnar Gerdts) Fram Pollution Observatory / Microplastics in the Arctic (in-house project; PIs: Melanie Bergmann, Ilka Peeken and Gunnar Gerdts) “Microplastics Reactor” [...] Defining the baselines and standards for microplastics analyses in European waters); www.jpi-oceans.eu/ecological-aspects-microplastics (PIs: Sebastian Primpke and Gunnar Gerdts) WT.SH project “Size

in different Arctic environments. Contact: A. Boetius, C. Bienhold, M. Wietz Literature: Cardozo Mino, M., Fadeev, E., Salman-Carvalho, V., Boetius, A. (2021). Spatial Distribution of Arctic Bacterioplankton [...] Effects of Ice-Algal Aggregate Export on the Connectivity of Bacterial Communities in the Central Arctic Ocean. Frontiers in Microbiology 9. doi: 10.3389/fmicb.2018.01035 Hoffmann, K., Hassenrück, C., Sal [...] Boetius, A. (2014): Composition, Buoyancy Regulation and Fate of Ice Algal Aggregates in the Central Arctic Ocean. PLOS One 9(9): e107452. doi:10.1371/journal.pone.0107452 Jacob, M., Soltwedel, T., Boetius, A

, e.g. in water bodies, the soil and the air. Via ocean currents and rivers, the tiny plastic particles can even reach the Arctic, Antarctic or ocean depths. A new overview study has now shown that wind [...] the Institute for Advanced Sustainability Studies in Potsdam, and the GEOMAR Helmholtz Centre for Ocean Research in Kiel – describes how microplastic finds its way into the atmosphere and how it is subsequently

of an Arctic Sea Ice–Ocean Model by a Genetic Algorithm, doi.org/10.1175/MWR-D-18-0360.1 Sumata, H., Kauker, F., Karcher, M. und Gerdes, R., 2019b: Covariance of Optimal Parameters of an Arctic Sea Ice–Ocean [...] the Arctic summer minimum sea ice extent in September from the beginning of the melting season in May/June on. While the strongest greenhouse gas induced changes are currently observed in the Arctic, it [...] However, this approach neglects all feedbacks of the sea ice-ocean system on the atmosphere. Since 2015 the initial state of the sea ice-ocean model is constrained by sea ice observations (data assimilation)