POLARSTERN long-term expedition planning

Goals:
• Long-term ecological research in the water column and at the seafloor to detect and track the impact of large-scale environmental changes and pollutants in the transition zone between the northern North Atlantic and the central Arctic Ocean, and to determine the factors controlling Arctic deep-sea biodiversity.
• Permanent presence at sea, from surface to depth, for the provision of near real-time data on climate variability and ecosystem change in an Arctic marine system. Annual maintenance and exchange of fixed and mobile autonomous scientific platforms (e.g. moorings, benthic crawler, bottom-lander) and sensors (e.g. RAS, O2, CO2)
• Remotely Operated Vehicle (ROV) and Bottom-Lander/Crawler based biological in situ long-term studies and experiments, simulating Climate Change related impacts on deep-sea benthic communities.

Goals:
Decadelong AWI-led investigations under the umbrella of HAFOS (Hybrid Antarctic Float and Ocean Observatory) combined shipboard surveys with oceanographic moorings and autonomous floats, and contributed significantly to the understanding of the circulation and the quantification of decadal variability and warming trends.The Weddell Sea features a rich and diverse ecosystem, complex sea-ice dynamics and intense ocean circulation. The physical and biogeochemical processes that prevail in the central Weddell Sea and the water mass formation on the heavily ice-covered southern and western shelves provide an important contribution to the global ocean circulation, sea level, and carbon sequestration.
The expedition aims at performing mooring and float operations, as well as shipboard physical and biogeochemical sampling:
i) along the Prime Meridian Transect between 50°S and the Antarctic continent;
ii) across the interior Weddell Gyre;
iii) in the gyre’s outflow region (Joinville Island transect) at the tip of the Antarctic Peninsula;
iv) inflow region off Kapp Norvegia.

Goals:
• Long-term ecological research in the water column and at the seafloor to detect and track the impact of large-scale environmental changes and pollutants in the transition zone between the northern North Atlantic and the central Arctic Ocean, and to determine the factors controlling Arctic deep-sea biodiversity.
• Permanent presence at sea, from surface to depth, for the provision of near real-time data on climate variability and ecosystem change in an Arctic marine system. Annual maintenance and exchange of fixed and mobile autonomous scientific platforms (e.g. moorings, benthic crawler, bottom-lander) and sensors (e.g. RAS, O2, CO2)
• Bottom-Lander/Crawler based biological in situ long-term studies and experiments, simulating Climate Change related impacts on deep-sea benthic communities.
• providing daily near-real time data on ocean surface and deep-water properties.
• providing a record documenting the warming of the Atlantic Water inflowing to the Arctic Ocean and its associated changes in transport and properties.
• study interactions and feedback mechanisms between the atmo-, cryo-, hydro-, bio-, and geosphere.
• obtain observations which link variations of daily (e.g., relevant for the preconditioning for phytoplankton blooms) to inter-annual (e.g., relevant to decipher decadal trends) timescales with processes in the atmo-, cryo-, hydro-, bio- and geosphere.
• quantify budgets and transports of energy and matter at different spatio-temporal resolutions from seasonal dynamics to inter-annual differences and decadal changes.
• identify the mechanisms which shape biodiversity of pelagic and benthic communities.
• assess the resilience of Arctic marine organisms and identify indicator species for community changes.
• contribute data for the assessment of ecosystem functions, services and the role of biodiversity therein.
• provide data for assessing the quality of remote sensing observations and of models simulating current and future changes in the Arctic Ocean.
• decipher how climate change mechanisms in the North Atlantic and the Arctic Ocean are coupled.
• assess plastic pollution in sea-ice, water-column and on the seafloor and benthic organisms to investigate long-term trends in plastic pollution and uptake in the food web.

Goals:
• Study the different key ice-ocean-ecosystem regimes with the same interdisciplinary team in the same year and season
• Characterize key processes that determine the observed sea ice, ocean, atmosphere and ecosystem changes in the Arctic Ocean
• Improve process understanding from floe- to regional-scales by merging ice station work, airborne observations, distributed networks and satellite data
• Add a spatial component to the MOSAiC time series and repeat a core set of observations carried out during ArcWatch 1-2 and aircraft campaigns

Goals:  
•the North Greenland and Transpolar source branches of the East Greenland Current
•their impact on marine terminating glaciers
•biogeochemical cycling / offshore carbon transport & export •glaciation and geological history of FramStrait   

Goals:
Transit cruise Bremerhaven - Walvis Bay

GOALS:
• Provide a baseline of the present state of biodiversity and ecosystem functions in the EWS against which change can be measured
• Study key variables of carbon, nutrient, and trace-element fluxes and cycling within and between the main ecosystem compartments sea ice, water column, and sea floor, as well as key species responsible for the carbon and nutrient transfer
• Ground-truth autonomous sampling devices for key biological variable

GOALS:
Collection of multidisciplinary information on the western Weddell Sea continental slope, shelf, and near Larsen C in order to

1. understand sea ice/ ice shelf/ ocean processes and to assess their impact on hydrographic and nutrient properties as well as on carbon fluxes from the surface to the deep sea
2. continue observations of long-term change and variability of sea ice thickness distribution and snow properties
3. characterize water masses and understand their formation, dispersion, pathways and shelf-basin exchange mechanisms
4. understand and map cryo-pelagic and cryo-benthic processes, and ecosystem parameters and gradients in dependence of sea ice conditions

Goals:
Transit Punta Arenas - Bremerhaven

Goals:
• Long-term ecological research in the water column and at the seafloor to detect and track the impact of large-scale environmental changes and pollutants in the transition zone between the northern North Atlantic and the central Arctic Ocean, and to determine the factors controlling Arctic deep-sea biodiversity.
• Permanent presence at sea, from surface to depth, for the provision of near real-time data on climate variability and ecosystem change in an Arctic marine system. Annual maintenance and exchange of fixed and mobile autonomous scientific platforms (e.g. moorings, benthic crawler, bottom-lander) and sensors (e.g. RAS, O2, CO2)
• Remotely Operated Vehicle (ROV) and Bottom-Lander/Crawler based biological in situ long-term studies and experiments, simulating Climate Change related impacts on deep-sea benthic communities.

Goals:
-Decipher the role of ridge systems for ocean current development and associated climate and environmental changes
-Elucidate central Arctic Ocean environmental conditions during warming climates (e.g., Miocene and Pliocene climate optima) 
-Investigate the onset and variability of 1) Arctic sea ice and 2) Greenland Ice Sheet in respect to paleo-sea level change 
-Unravel ice-ocean-atmosphere interactions that controlled the Cenozoic climate transition (Greenhouse to Icehouse) 
-Identify teleconnections between Arctic and Southern Ocean cryosphere developments   

Goals:
Transit cruise Bremerhaven - Walvis Bay

GOALS:
• Revealing both the timing of and environmental conditions just before, during, and after initial AIS formation at E/O boundary, i.e. transition from green- to icehouse conditions
• Identifying ice-proximal conditions during initial WAIS growth and during the mid-Miocene climatic optimum
• Constraining potential WAIS collapses during Plio- and Pleistocene super-interglacials in the key region for both understanding WAIS stability and defining tipping points
• Applying multi-proxy data from those critical time slices of AIS history as reliable target values for testing, validating, and improving numerical palaeo-ice sheet and climate models

GOALS:
• Krill stock assessment and niche partitioning between whales and krill in relation to krill fishing activity
• German contribution to CCAMLR in CCAMLR division 48.1
• The impact of key macrozooplankton grazers (salps, krill) on the biological carbon pump, iron remineralisation and its impact on primary productivity

Goals:
Transit cruise Punta Arenas - Bremerhaven