2022 ), and to include the sensitivity of phytoplankton growth to ocean acidification ( Seifert et al., 2022 ). Main REcoM references (chronological order): •[3 phytoplankton functional groups and CO2 [...] Schwinger, J., Séférian, R., 2020. Consistency and Challenges in the Ocean Carbon Sink Estimate for the Global Carbon Budget. Front. Mar. Sci. 7, 571720. doi.org/10.3389/fmars.2020.571720 •[Arctic [...] , 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, 65-81, doi:10.1016/j.pocean

tightly coupled to the global circulation of the atmosphere and the ocean. The climate of the Arctic is subject to visible changes and the sea-ice albedo feedback mechanism acts as an amplifier of climate change. The observed decrease of Arctic summer sea ice cover over the last decades is best viewed as a combination of strong natural variability due to large-scale dynamics [...] aerosols in the Arctic and its role for climate change. Processes in polar regions, connected with a variety of feedbacks, including cloud-, aerosol-,

The role of clouds and warm air masses from the open ocean for the rapid warming of the Arctic is at the heart of a recent Alfred Wegener Institute project on Svalbard. The researchers are

Changing Arctic Carbon cycle in the cOastal Ocean Near-shore - CACOON No other region has warmed as much or as rapidly in the past decades as the [...] globally from land to ocean, despite the Arctic Ocean making up only approximately 1% of the Earth’s ocean volume. Arctic shelf waters are therefore dominated [...] on the type and fate of river-borne organic matter delivered to Arctic coastal waters, and the resultant changes to ecosystem functioning in the coastal Arctic Ocean. We will achieve this through a

targets four events: heat waves, hydrological extreme events , ocean eddies and the thawing of permafrost . Hydrological extreme events Recent global projections predict a 10-20 % increase in the [...] and a large portion of the Siberian and North American shelves. Arctic warming occurs at a much higher rate (by up to 8 to 10 times) compared to the rest of the world. Warming permafrost thaws and degrades

water input, which affects density and salinity layers of the ocean. Besides its direct climatic impact, the snow layer also adds to the uncertainty of sea ice thickness estimates by satellite altimeters [...] ice (Photo: Alfred Wegener Institut) We deploy snow buoys in the Arctic and Antarctic. They are equipped with echo sounders to record changes at the snow surface. Buoy data can be accessed via the

with respect to tipping points Horizon 2020: OceanNETs : Ocean-based Negative Emission Technologies - analyzing the feasibility, risks, and co-benefits of ocean-based negative emission [...] by Alkalinity Enhancement: Potential, Benefits and Risks BMBF nuArctic: Towards a better understanding of the nutrient cycles in the ‘new’ Arctic Ocean and implications for future primary productivity and carbon export OceanICU : OceanICU is a Horizon Europe project aiming to produce new data, information and understanding on the role of the Ocean in the

marine organisms under pressure. However, jellyfish in the world’s oceans could actually benefit from the rising water temperatures – also and especially in the Arctic Ocean, as researchers from the Alfred [...] successfully shown. In computer models, they exposed eight widespread Arctic jellyfish species to rising temperatures, sea ice retreat and other changing environmental conditions. The result: by the second [...] potentially dramatic consequences for the marine food web and Arctic fish populations. The study was just released in the journal Limnology and Oceanography.

Threshold in North Atlantic-Arctic Ocean circulation controlled by the subsidence of the Greenland-Scotland Ridge , Nature Communications, 8 (15681), pp. 1-13, doi: [...] , R., Fahl, K., Gierz, P. , Niessen, F. and Lohmann, G. (2017): Arctic Ocean sea ice cover during the penultimate glacial and the last interglacial , Nature Communications, 373, doi: 10.1038/s41467-017 [...] 2016), Evidence for ice-free summers in the late Miocene central Arctic Ocean , Nature Communications, 7, pp. 1-13, doi: 10.1038/ncomms11148 . Abelmann, A., Gersonde, R. , Knorr, G. , Zhang, X. , Chapligin

to investigate impactsof past and future climate changes in the Arctic. Since permafrost is usually not visible at the earth’s surface and only few measurement sites exist, models are also important to [...] , permafrost models give us insights into the evolution of Arctic landscapes and help us understand how these unique ecosystems respond to natural and human-caused disturbances. Permafrost models [...] interactions between permafrost, vegetation, snow, lakes, and the Arctic ocean. Furthermore, we use our models to gain insights into important ecosystem functions such as the water and carbon cycles. We