MOSAiC Expedition
[5] The international expedition, which involved more than 80 institutions from 20 countries (Austria, Belgium, Canada, China, Denmark, Finland, France, Germany, Italy, Japan, the Netherlands, Norway, Poland, Russia, South Korea, Spain, Sweden, Switzerland, the United Kingdom, and the United States),[6] was conducted by the AWI and was led by the polar and climate researcher Markus Rex and co-led by the atmospheric researcher Matthew Shupe from the University of Colorado Boulder.
U.S. participation was primarily supported by the National Science Foundation, which contributed roughly $24 million to the project, among the largest Arctic research initiatives the agency has ever mounted.
During MOSAiC, for the first time the Fram’s drift was repeated with a research icebreaker, equipped with a veritable arsenal of cutting-edge instruments for exploring and recording the complex climate processes in the Central Arctic.
On 4 October 2019, at a position of 85° North and 134° East, the MOSAiC expedition found a suitable ice floe, which measured roughly 2.5 by 3.5 kilometres.
On 13 August, after a last big refueling and personnel rotation, Polarstern started steaming towards the Central Arctic to study the onset and early freezing phase of the sea ice.
[7][20] In addition, the outcomes of the MOSAiC mission will help to understand the regional and global effects of Arctic climate change and the loss of sea ice.
[12] Routine radiosonde observations in combination with tethered balloon measurements provided high-resolution profiles of the atmospheric conditions in the column of air above the MOSAiC site.
In addition, radar measurements were used to determine the vertical profile of wind speed and direction as well as key cloud properties, including ice and liquid water content.
Key thermodynamic parameters, as well as the kinematic structures of the atmosphere, were investigated with the aid of microwave and infrared radiometers, Raman and Doppler lidar.
The sea-ice observations covered the broad range from the physical and mechanical characteristics of Arctic sea ice, to its morphology, optical properties and mass balance.
Additionally, underwater sea ice topography and other physical parameters were measured using observations from remotely operated vehicle, as well as biophysical characterization of algae habitats.
[33] Ocean processes influence the energy balance in the Arctic, as well as the growth and melting of sea ice due to additional warmth.
Measurements from the water column will shed new light on key mechanisms occurring in the ocean, e.g.: (1) heat exchange between sea ice and ocean, (2) absorption of sunlight and processing of the resulting heat, (3) interaction with deep sea processes, and (4) primary biological productivity and export of organic matter from the euphotic zone.
[12] For this purpose, continuous measurements were taken of turbulent fluxes directly below the ocean-ice boundary, to help understand the speeds of the ice and ocean, vertical thermal and momentum flows, diffusion of mass and other key processes.
[13] The observations on biological and biogeochemical transformation and succession mainly focussed on analysing samples from all three major physical regimes, i.e., the ice, snow and water environments.
[13] The latter offered insights into the biogeochemistry of the net air/ice flow of CO2 produced by sea ice, and into the potential for capturing organic carbon and the respiration of CO2.
A third key element: observing the cycles of biogenic gases like N2O, O2, DMS (dimethyl sulphide) and bromoform in the snow, sea ice and water, which contributed to our grasp of the underlying biogeochemical paths.
