Atmosphere and coupled system science at MOSAiC
Shupe, Matthew — University of Colorado
Area of research:
The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition comprised a year of coupled atmosphere, sea ice, and ocean measurements in the rapidly changing central arctic sea ice. Observations from the campaign are providing deep and unprecedented insight into physical, chemical, and biological processes that cut across the arctic system and are inextricably linked with arctic change.
Based on the year in the arctic sea ice, scientists are advancing our understanding of the sources and properties of arctic aerosols, the influences clouds have on the surface energy budget, precipitation as a sink of atmospheric moisture and source of snowfall on the surface, the evolving structure of the stratified boundary layer, the impacts of storms on sea ice movement and melt, and many other atmospheric processes and their interactions with the sea ice, snow, ocean, and ecosystem. Collectively, these observations and analyses are forming the foundation for unique model process assessment that will lead to advanced model predictive capabilities.
The arctic system is in a state of rapid transition, with rising temperature, declining sea ice, and uncertain interactions with the global climate system. Models struggle to represent many of the unique features of the arctic system, including mixed-phase clouds, stable atmospheric boundary layers, the partitioning of surface energy budget terms, the layering of ice and snow, ocean mixing, and many others. To help address these needs, the MOSAiC expedition drifted with the sea ice in the central Arctic from September 2019 to September 2020 to help answer the leading question: What are the causes and consequences of an evolving and diminished arctic sea ice cover? While sea ice and its change was the scientific nexus of MOSAiC, the expedition was designed to study all related aspects of the central arctic climate system and its interactions. To complete this largest arctic scientific expedition in history required a broad consortium of international institutions and agencies, including the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility, which operated its second Mobile Facility as a major component of the MOSAiC atmospheric program. Overall, the expedition has produced a huge legacy of data that is unlike anything available in the past for understanding and modeling the arctic system. A collection of overview papers outline the MOSAiC programs for atmosphere, sea ice and snow, and ocean research, and how these were designed to support multidisciplinary science and model advancement.