Breakout Summary Report


ARM/ASR User and PI Meeting

Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC)
24 October 2022
1:30 PM - 3:30 PM
Matthew Shupe and Jessie Creamean

Breakout Description

MOSAiC was a yearlong drifting expedition in the central arctic sea ice from fall 2019 to fall 2020. The ARM Mobile Facility 2 participated, along with many other international participants, providing comprehensive observations of the central arctic atmosphere, sea ice, snow, and ocean from physical, chemical, and biological perspectives. The expedition produced essential, and many first-of-their-kind, data sets regarding atmospheric structure, cloud and aerosol properties, surface energy budgets, and their interactions with the coupled arctic system. Two years after the completion of the expedition, there is a large community of MOSAiC scientists pursuing research on many related topics. This session is an opportunity to share ongoing MOSAiC research, identify additional research opportunities, and discuss how ongoing observational activities can support model studies and assessments.

Main Discussion

Following a number of presentations, the main discussion covered two primary themes: 1) Questions and discussion related to the MOSAiC data that are available to support research; 2) Topics to focus on more broadly as a community, including modeling themes.
For the first theme: we identified and briefly discussed some of the key products that have been derived for MOSAiC, including the new and in-development VAPS that were presented in one of the presentations, including the ARMBECLOUD and Radflux products.  Additionally, we highlighted some PI products including a radar-based snowfall data set, liquid-cloud back trajectories, and cloud microphysics data set.  Lastly, there was some discussion about what additional measurements are needed from others within MOSAiC to enable the final production of ARM VAPS like the AERIoe. Some discussions extending after the session also touched on this topic, highlighting the desire of the community to have synthesis data sets that combine many different measurements as a means to support model evaluation.  Lastly, there was a suggestion that one way to support broader us of the MOSAiC data is to provide some way to composite based on key types of conditions (such as the occurrence of single-layer clouds). This approach might be related to the ARM Data Discovery’s new focus on “data epochs”.
For the second main discussion point, there were nice contributions about people’s interests going forward for modeling activities.  These included:
●      Aerosol sources and their interactions with clouds: Specifically, to assess if ground-based measurements are representative for aerosol abundance aloft and interactions with clouds
●      Atmosphere – surface interactions via surface energy budgets, momentum transfer, and links to conditions within the sea ice.
●      Cloud microphysics: It was acknowledged that this is a unique opportunity to study microphysics over the central arctic sea ice, and this might help us to make further progress over the past progress made as part of MPACE, ISDAC, and other campaigns.
●      Cloud – turbulent interactions. A few people thought this might be the best path forward as there are many great measurements of the vertical turbulent structure of the boundary layer and clouds, and this is an area that has had little focus in the past. In particular there was interest in how cloud-driven turbulence serves to shape the arctic boundary layer, how this relates to turbulent transport of key constituents like aerosols, and how this also impacts the sea-ice surface.
●      Vertical velocity at fine scales. This theme is related to the last, and would help to provide further information and constraints on sub-grid velocities. 
●      General concepts of coupling. It was recognized that perhaps more than most other campaigns, MOSAiC offers a very obvious opportunity to examine coupling between the atmosphere and the surface, as well as coupling to processes that manifest in the ocean, sea ice, ecosystem, chemistry, and more.
Lastly, in discussions of modeling, it became apparent that there are many different modeling interests, and these play out at different scales and levels of complexity. Regional coupled models, LES simulations, Lagrangian modeling, single-column models, large-scale models constrained in various ways, trajectory models. We recognized the need to further discuss ways to leverage these different scales. In this regard, some groups have interest in performing nested simulations that can serve to bridge scales. One novel approach here would be to nest a Lagrangian LES within a regional mesoscale model domain. LES nested within mesoscale models has been done before, but the adaptation to a Lagrangian trajectory through the mesoscale domain would offer a new perspective with potential to address some pressing questions about airmass evolution that are of particular relevance to atmospheric processes over the central arctic sea ice.

Key Findings





Some side discussions focused on the need for forcing data sets to drive MOSAiC model simulations. This issue of forcing data sets is a challenging one, and one that would have to be addressed prior to the eventual (possible) application of LASSO to the MOSAiC domain. A couple of groups are working on these issues in some ways, and we recognize the need to have further discussions to leverage what has already been accomplished so different groups do not need to duplicate efforts.



Future Plans

The discussion of modeling ideas will contribute to a similar discussion session that will be part of the 2nd MOSAiC Science Conference in February 2023. The objective is to identify areas of synergy across different modeling efforts to make those efforts more impactful and complementary. In the longer term, we expect these discussions to eventually lead to a coordinated modeling activity across the MOSAiC and ARM/ASR communities.

Action Items

MOSAiC data (non-ARM) are archived in multiple locations, and sometimes people are not familiar with those other locations. It was suggested that the ARM Data Center provide some information on how to link with these external resources and archives. Shupe will discuss this point with the ARM Data Center.