Plattform Platform	Reise-Nr. Cruise-No.	Zeitraum Period	Projekt Project	Arbeitsgebiet Working area
Polarstern	PS126	24.05.2021 - 27.06.2021	FRAM CHANGING EARTH INTAROS ICOS SIOS TIEFSEE-OBSERVATORIUM HAUSGARTEN	Fram strait

Fahrtleiter Chief Scientist	Institut Institute	Auslaufhafen Port of departure	Einlaufhafen Port of return	Stationskarte Station map	Schiffsroute Trackchart
Soltwedel Thomas	Alfred-Wegener-Institut fur Polar- und Meeresforschung	Bremerhaven	Bremerhaven

Ziel der Reise / Objectives of Cruise:

The RV Polarstern expedition PS126 started on 24 May 2021 in Bremerhaven and led to the Fram Strait between Greenland and the Svalbard archipelago. The expedition contributed to various large national and international research and infrastructure projects (FRAM, INTAROS, ICOS, SIOS, ARCHES) as well as to the new research programme ?Changing Earth - Sustaining our Future" (?Erde im Wandel - Unsere Zukunft nachhaltig gestalten") of the Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research (AWI). In Topic 6 "Marine and Polar Life: Sustaining Biodiversity, Biotic Interactions and Biogeochemical Functions" (Subtopics 6.1 "Future ecosystem functionality" and 6.3 "The future biological carbon pump") of the new research programme, ecosystem shifts in the pelagic and deep ocean associated with water temperature increase and sea ice retreat are identified and quantified, and feedback processes on oceanographic processes are investigated. These studies include the identification of spatial and temporal developments in the function of selected pelagic and benthic communities and the establishment of a comprehensive repository of observational data. In Subtopic 6.4 "Use and misuse of the ocean: Consequences for marine ecosystems", the input of plastic waste into the ocean, the vertical fluxes of plastic from the sea surface to the seafloor and the interaction between plastic and marine biota are investigated. The expedition supported the time-series studies at the LTER (Long-Term Ecological Research) observatory HAUSGARTEN, where we document Global Change induced environmental variations on a polar deep-water ecosystem. This work is carried out in close co-operation between the HGF-MPG Joint Research Group on Deep-Sea Ecology and Technology, the PEBCAO Group ("Phytoplankton Ecology and Biogeochemistry in the Changing Arctic Ocean") at AWI and the Helmholtz Young Investigators Group SEAPUMP ("Seasonal and regional food web interactions with the biological pump"), representing a joint effort between the AWI, the MARUM - Center for Marine Environmental Sciences, and the University of Bremen. The expedition was further used to accomplish installations for the HGF infrastructure project FRAM (Frontiers in Arctic marine Monitoring). The FRAM Ocean Observing System aims at permanent presence at sea, from surface to depth, for the provision of near real-time data on Earth system dynamics, climate variability and ecosystem change. It serves national and international tasks towards a better understanding of the effects of change in ocean circulation, water mass properties and sea-ice retreat on Arctic marine ecosystems and their main functions and services. FRAM implements existing and next-generation sensors and observatory platforms, allowing synchronous observation of relevant ocean variables as well as the study of physical, chemical and biological processes in the ocean. Experimental and event-triggered platforms complement the observational platforms. Products of the infrastructure are continuous long-term data with appropriate resolution in space and time, as well as ground-truthing information for ocean models and remote sensing. During the technically and logistically very challenging expedition we used different autonomous underwater vehicles, which operated in the water column (Autonomous Underwater Vehicle, AUV) and on the deep seafloor (Benthic Crawler). The cruise ended on 27 June 2021 in Bremerhaven.

Messungen / Measurements

Verankerungen / Moorings