MOSAiC expedition

MOSAiC expedition
Name	MOSAiC expedition
Period	2019–2020
Location	Central Arctic
Lead	Alfred Wegener Institute
Vessel	Polarstern
Participants	Multinational scientific teams
Objective	Year‑round Arctic observations

MOSAiC expedition The MOSAiC expedition was a year‑long multinational Arctic drift campaign led by the Alfred Wegener Institute that embedded the research icebreaker Polarstern into sea ice to study climate processes. The project gathered researchers from institutions such as the Max Planck Society, University of Cambridge, University of Washington, Columbia University, University of Tromsø, University of Alaska Fairbanks, and agencies including National Science Foundation and European Space Agency. A core aim was to improve representations in models used by the Intergovernmental Panel on Climate Change and operational services like Copernicus Programme and NOAA.

Background and Objectives

The initiative arose amid accelerating Arctic change observed by programs such as International Arctic Science Committee and campaigns like Arctic Council‑sponsored assessments. Motivated by gaps highlighted in reports from the Intergovernmental Panel on Climate Change and the World Meteorological Organization, planners sought continuous, interdisciplinary observations spanning atmosphere, sea ice, ocean, ecosystem, and biogeochemical processes. Stakeholders included national institutes such as the Alfred Wegener Institute, the Norwegian Polar Institute, and research universities like Massachusetts Institute of Technology, University of Oslo, and McGill University aiming to constrain uncertainties in climate projections used by bodies such as the European Commission and United Nations Environment Programme.

Expedition Timeline and Logistics

The drift began when the Polarstern was deliberately frozen into pack ice in late 2019 near the Laptev Sea marginal ice zone, continuing through 2020 across the Central Arctic toward the Fram Strait. The timeline involved seasonal campaigns timed with phenomena studied by platforms such as ICESat-2, Sentinel-1, CryoSat, Argo floats, and research aircraft like Polar 6 and P3 Orion. Logistics required coordination with icebreaker escorts from countries including Russia and Norway, air drops by operators like Kenn Borek Air, and supply links to bases such as Longyearbyen and Barrow, Alaska. Safety and contingency planning referenced standards from the International Maritime Organization and polar procedures used by the United States Coast Guard and Canadian Coast Guard.

Vessel and Equipment

The primary platform was the Polarstern, an icebreaker operated by the Alfred Wegener Institute outfitted with laboratories, winches, and helicopter facilities. Instrumentation included lidar systems referenced by groups at University of Leeds and microwave radiometers tested by teams from DMI (Danish Meteorological Institute). Autonomous systems such as AUVs and gliders were deployed alongside drifting buoys coordinated with the Global Drifter Program and International Arctic Buoy Programme. Ice coring rigs and snow probes from laboratories at ETH Zurich and University of Alaska Fairbanks enabled stratigraphy studies linked to paleoclimate groups at University of Bern and Lamont-Doherty Earth Observatory.

Scientific Goals and Research Themes

Research themes targeted atmosphere–ice–ocean interactions central to processes examined by the Intergovernmental Panel on Climate Change and projects like CliC (Climate and Cryosphere). Key foci included radiative transfer studied by teams from NCAR and NOAA, turbulent fluxes measured with eddy covariance arrays developed at University of British Columbia, sea‑ice mechanics addressed by specialists at University of Cambridge and University of Bremen, and ocean mixing explored by researchers from Scripps Institution of Oceanography. Biogeochemical and ecosystem investigations engaged experts from Woods Hole Oceanographic Institution, Max Planck Institute for Marine Microbiology, and University of Gothenburg assessing carbon fluxes and microbial dynamics relevant to the Global Carbon Project.

Key Findings and Publications

Results revealed unexpectedly thin, dynamic sea ice and complex snow cover effects on albedo, informing improvements in models employed by ECMWF and incorporated in assessments by the Intergovernmental Panel on Climate Change. Observations documented heat flux pathways between the Atlantic Water layer and surface, corroborating hypotheses from studies at Norwegian Polar Institute and University of Bergen. Publications appeared in journals including Nature, Science, Geophysical Research Letters, and The Cryosphere, with syntheses led by consortia from Alfred Wegener Institute, Potsdam Institute for Climate Impact Research, and University of Exeter. Data contributions fed into operational datasets managed by Copernicus Programme and climate reanalyses by ECMWF.

Environmental and Political Context

The expedition occurred against a backdrop of rapid Arctic warming, diminishing multiyear ice documented by agencies such as NOAA and NASA, and heightened strategic interest from states including Russia, United States, China, and Norway. Scientific objectives intersected with policy dialogues in forums like the Arctic Council and climate negotiations under the United Nations Framework Convention on Climate Change. Environmental concerns included impacts on indigenous communities linked to organizations like the Inuit Circumpolar Council and wildlife monitored by programs at the World Wildlife Fund and IUCN.

Legacy and Ongoing Impact

The campaign established a rich legacy of open datasets, methodological advances, and strengthened networks among institutions such as Alfred Wegener Institute, Max Planck Society, University of Alaska Fairbanks, and University of Cambridge. Follow‑on projects and observing systems coordinated with Copernicus Programme, NASA missions, and international networks including the Global Ocean Observing System aim to sustain long‑term monitoring inspired by the expedition. The program also influenced training and capacity building at universities like University of Tromsø and research centers such as Potsdam Institute for Climate Impact Research, shaping future Arctic science and operational services.

Category:Arctic expeditions Category:Climate science