atmosphere - sea-ice - ocean system; to study the history of the transpolar system. Contact: T. Soltwedel, J. Hölemann, R. Stein BIOACID III (Biological Impacts of Ocean ACIDification) Project funded by the [...] GEOMAR, Germany The overarching questions of BIOACID -Project are: What are the effects of ocean acidification on marine organisms and their habitats? What are the underlying mechanisms of responses and [...] GEOMAR, Germany Objectives of the TRANSDRIFT -Project are: to assess the influence of sea-ice and ocean dynamics in the Laptev Sea on the transpolar drift; to investigate changes in the arctic halocline

in a changing Southern Ocean In large areas of the worlds oceans iron (Fe) limits primary production thus affecting the global carbon cycle. One such area is the Southern Ocean (SO). In addition to Fe [...] primary production with iron in the Southern Ocean. We will also address the question how Zn/Co/B12 co-limitation with iron is modulated by ocean acidification. To confirm Zn/Co/B12-limitation or co-limitation [...] trace metals and explore how these relationship may change with increasing CO2 and resulting ocean acidification. This multifaceted approach between laboratory experiments and field studies will shed light

pool (38,000 Pg of carbon) in the ocean, and plays a key role in the solubility pump; it is therefore of relevance to both ocean carbon dioxide uptake and ocean acidification. While recognising the importance [...] player in the global carbon cycle. Ocean colour is also used to study export production: the fraction of primary production that is transported to the deep ocean. Ocean-colour data are also being used i [...] Other applications include studies of cross-domain fluxes and interactions: ocean-atmosphere and land-ocean fluxes of carbon, ocean-cryosphere interactions and climate impact on the polar ecosystems. It must

pool (38,000 Pg of carbon) in the ocean, and plays a key role in the solubility pump; it is therefore of relevance to both ocean carbon dioxide uptake and ocean acidification. While recognising the importance [...] player in the global carbon cycle. Ocean colour is also used to study export production: the fraction of primary production that is transported to the deep ocean. Ocean-colour data are also being used i [...] Other applications include studies of cross-domain fluxes and interactions: ocean-atmosphere and land-ocean fluxes of carbon, ocean-cryosphere interactions and climate impact on the polar ecosystems. It must

influences. One of our priority questions is how environmental parameters (temperature, hypoxia, ocean acidification, pollution) and their combination affect fish, mussels and snails. One focus is on the cellular

of the Paris Climate Agreement is not achieved. Under conditions of further warming and acidification of the ocean, Atlantic cod and its arctic relative polar cod would be forced to look for new habitats

all latitudes. Cold-water corals (CWC) have long been considered particularly vulnerable to ocean acidification, but in the naturally acidified fjords of Patagonian Chile, we found large populations of CWC

2013). Besides water temperature increase, expanding ocean acidification will pose another threat to pelagic and benthic life in the Arctic Ocean (e.g. Bates et al., 2009; Lischka & Riebesell, 2012; AMAP [...] Changing Arctic Ocean) focusses on the plankton community and the microbial processes relevant for biogeochemical cycles of the Arctic Ocean. This research focus is acknowledging that the Arctic Ocean has gained [...] In addition, the chemical equilibrium and the elemental cycling in the surface ocean will alter due to ocean acidification. These environmental changes will have consequences for the biogeochemistry and

we do about the ocean depths. Yet the deep sea is not a habitat fully separated from the surface; it is already undergoing dramatic changes in response to warmer water, ocean acidification and environmental [...] the so-called mid-oceanic ridges – volcanically active mountain chains that usually extend one to three kilometres above the seafloor and can be found in all (of) the world’s oceans. With a total length [...] standards. For another, food is harder to come by. The central Arctic Ocean is largely covered with ice and – unlike the Antarctic’s Southern Ocean – surrounded by landmasses. Exchanges with the Atlantic and Pacific

already impacting the modern ocean. To recognize changes and predict the future ocean, ocean color (OC) remote sensing aims at quantifying and monitoring optically active oceanic constituents such as phytoplankton [...] 2.2 Ocean color remote sensing 2.2 Ocean color remote sensing Ocean color (OC) remote sensing (Mobley, 1994; Mobley et al., 2021) refers to the dis- cipline that infers information on the ocean from optical [...] c CO2 was taken up by the ocean (Friedlingstein et al., 2019). As a consequence, the ocean is warming, sea levels are rising, sea ice concentrations are declining, and ocean acidity is enhancing (IPCC