Breakout Summary Report
ARM/ASR User and PI Meeting
High Latitude Processes
26 June 2020
2:00 PM - 4:00 PM
135
Gijs de Boer, Greg McFarquhar
26 June 2020
2:00 PM - 4:00 PM
135
Gijs de Boer, Greg McFarquhar
Breakout Description
The High Latitude Processes Working Group focuses on the understanding and modelrepresentation of physical processes controlling the surface energy budgets in northern and southern
high-latitude regions. This includes work to understand: 1) cloud microphysical and macrophysical
properties, with emphasis on hydrometeor (rain, snow, etc.) phase division and ice crystal properties; 2)
aerosol particle properties, including sources and transport, chemical and optical properties, and the role
of the particles in cloud structure; 3) tropospheric states (pertaining to the lowest atmospheric layer,
where most weather occurs), including the role of clouds in atmospheric mixing, development of
convective boundary layers in regions with diverse surface conditions, and the role of microscale and
mesoscale meteorological circulation patterns on thermodynamic evolution; and 4) surface-atmosphere
interactions, including elements affecting radiative and turbulent surface energy exchange.
Participants: Please contact Gijs de Boer (gijs.deboer@colorado.edu) and Greg McFarquhar
(mcfarq@ou.edu) if you have suggestions for discussion topics.
Main Discussion
This breakout session consisted of three main sections. The group started with an introduction to the group and the purpose of the meeting, as well as a quick overview of the virtual meeting format. Unfortunately, the virtual format did not allow us to conduct the face-to-face informal introductions that we have implemented for the last several years which have helped to aid the development of a friendly and collaborative atmosphere between working group members. This activity is thought to greatly enhance the functionality of the working group and also helps to foster lively and open discussion during the breakout session. The inability to do this using the online platform, along with some limitations of the platform itself, resulted in a breakout session that was more heavily focused on presentations than on discussion. We hope to spark follow-up discussion through HLPWG emails as well as potentially through follow-on virtual workshops aimed at key topics identified as part of these presentations.After a brief introduction, several short presentations were given summarizing important organizational efforts within ARM and ASR. These summaries were requested in order to ensure that the entire working group was aware of these efforts and to allow the group to respond in the form of questions and follow-up discussion. These summaries covered the following topics, all of which require additional input from the working group:
• The ARM decadal vision [J. Mather]
• Updates on the status of the AMF-3 at OLI and the timing of removal of this system from its present location [J. Hardesty]
• Information on potential collaborations between ARM and NOAA for aerosol instrumentation at NSA [J. Hardesty/A. McComiskey]
• A brief introduction of the questions surrounding the future of advanced lidar systems at NSA
• The Cloud and Precipitation Measurements and Science Group (CPMSG), its current goals, and opportunities for input [A. Fridlind]
Following this series of short presentations, the focus of the working group shifted to field recent and ongoing field campaigns, with presentations included to cover:
• Measurement of Aerosols, Radiation and Clouds over the Southern Oceans (MARCUS) / Macquarie Island Cloud and Radiation Experiment (MICRE) [G. McFarquhar]
• The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) [G. de Boer]
• Cold Air Outbreaks in the Marine Boundary Layer Experiment (COMBLE) [B. Geerts]
• Ongoing aerosol campaigns on the North Slope [K. Pratt]
• Ice Fog Field Experiment at Oliktok Point (IFFExO) [I. Gultepe]
Despite challenges associated with COVID-19, ongoing campaigns were reported to be going well, and data analysis for completed campaigns is ongoing. The IFFExO campaign has been delayed due to challenges with accessing Oliktok Point at the current time. Potential future coordination between IFFExO and the ongoing aerosol campaigns was noted as there are still plans to collect 50 filters at Oliktok before moving to the SEUS.
Finally, the Working Group breakout session featured a series of four scientific presentations, two featuring work completed in the Southern Hemisphere, and two featuring work completed in the Northern Hemisphere. This included the following presentations:
• Snow measurements around NSA and insight into potential re-deployment of snow sensors [M. Sturm]
• Multi-frequency radar signatures of ice and snow from the AWARE campaign [F. Tridon]
• Low-level clouds and large scale forcing over the Southern Ocean [C. Naud]
• Vertical structure of aerosols in the lower Arctic atmosphere [J. Creamean]
These presentations resulted in some lively discussion using the Q+A feature of Zoom. In particular there is a need to continue discussions on the potential for re-deploying Oliktok Point snow/precipitation sensors to other locations on the North Slope, perhaps as a mini-network around the NSA facility. Discussions about the applications of different wavelength radars also abounded.
Key Findings
NoneIssues
As stated above, the muted nature of discussion resulting from a virtual workshop requires that additional email- or in-person discussions take place on a variety of these topics. We hope to be able to facilitate such discussions in the months ahead.Despite this, a number of issues were discussed on the Q+A section of zoom during and after the short presentations covering the decadal vision through the CPMSG. It was noted that there were no plans to fly the TBS beyond June 2021 at Oliktok Point, but that there were still possibilities to fly at limited range from Utqiagvik and at non-ARM sites as approved. Discussions about the coordination between NOAA and ARM also noted that aerosol monitoring needs had been identified at the IGAC (International Global Atmospheric Chemistry) workshop in Dec. 2019. It was also noted that IOPs could still be requested and there was considerable discussion about the relative merits and disadvantages of both the HSRL and Raman lidar. It was felt that it would be useful to prepare a document for the working group summarizing the things that the HSRL can do better than the Raman, while noting the more complete set of capabilities that the Raman offers. The group could then be surveyed on their preferences based on this document.