The MOSAiC Distributed Network: Observing the coupled Arctic system with multidisciplinary, coordinated platforms

Abstract

Central Arctic properties and processes are important to the regional and global coupled climate system. The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) Distributed Network (DN) of autonomous ice-tethered systems aimed to bridge gaps in our understanding of temporal and spatial scales, in particular with respect to the resolution of Earth system models. By characterizing variability around local measurements made at a Central Observatory, the DN covers both the coupled system interactions involving the ocean-ice-atmosphere interfaces as well as three-dimensional processes in the ocean, sea ice, and atmosphere. The more than 200 autonomous instruments (“buoys”) were of varying complexity and set up at different sites mostly within 50 km of the Central Observatory. During an exemplary midwinter month, the DN observations captured the spatial variability of atmospheric processes on sub-monthly time scales, but less so for monthly means. They show significant variability in snow depth and ice thickness, and provide a temporally and spatially resolved characterization of ice motion and deformation, showing coherency at the DN scale but less at smaller spatial scales. Ocean data show the background gradient across the DN as well as spatially dependent time variability due to local mixed layer sub-mesoscale and mesoscale processes, influenced by a variable ice cover. The second case (May–June 2020) illustrates the utility of the DN during the absence of manually obtained data by providing continuity of physical and biological observations during this key transitional period. We show examples of synergies between the extensive MOSAiC remote sensing observations and numerical modeling, such as estimating the skill of ice drift forecasts and evaluating coupled system modeling. The MOSAiC DN has been proven to enable analysis of local to mesoscale processes in the coupled atmosphere-ice-ocean system and has the potential to improve model parameterizations of important, unresolved processes in the future.

In-ice light measurements during the MOSAiC expedition

“…They were additionally equipped with 3 RAMSES spectral radiometers (TriOS Optical Sensors, Rastede, Germany) that recorded spectrally resolved incoming, reflected, and downwelling transmitted planar solar irradiance. All three systems were initially deployed on MOSAiC Legs 3–4: one co-located with the lightharp at the above-mentioned LM site (2020R11 12 ), one at a remote buoy location called the L3 site that was part of a distributed network 13 of autonomous buoys around the MOSAiC sampling site (2020R12 14 ), and one in the Central Observatory (CO) of the MOSAiC expedition (2020R10 15 ). Buoy 2020R11 was recovered in late July/early August 2020 and was redeployed on Leg 5 within a melt pond at the main buoy site as 2020R21 16 .…”

Dynamical reconstruction of the upper-ocean state in the central Arctic during the winter period of the MOSAiC expedition

“…To fill this gap, the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC; e.g. Rabe et al, 2022) designed a distributed network (DN; Rabe et al, 2024) of autonomous icetethered systems (hereafter referred to as "buoys") around the MOSAiC Central Observatory (CO). The CO included a series of buoys and mostly manual ocean observations at the R/V Polarstern and a site about 300 m away from the ship ("Ocean City"; OC).…”