Breakout Summary Report
ARM/ASR User and PI Meeting
2 - 6 May 2016
Secondary Organic Aerosol
2 May 2016
3:30 PM - 5:30 PM
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John Shilling
2 May 2016
3:30 PM - 5:30 PM
0
John Shilling
Breakout Description
The guiding philosophy for cooperative science of the Secondary Organic Aerosol (SOA) Group, both for incorporating knowledge into models and identifying new and important emerging topics for study, is to focus on processes of SOA formation and reactivity that are missing in global climate models and have large potential implications on radiative forcing. The goals of the session are: to share and discuss the latest results ASR/ARM-funded SOA researchers including laboratory, field, and modeling efforts and to plan for future collaborative efforts and emphases.Main Discussion
The session was composed of three parts; an update from PIs on research progress, a discussion of the SOA workshop held at PNNL in June 2015, and a discussion of ARM measurement needs.In the first part of the session, Alla Zelenyuk, Jose Jimenez, Joel Thornton, Qi Zhang, Markus Petters, and Scot Martin gave 2-3 slide overviews on their ASR projects.
The second part of the session encompassed the majority of the time and was devoted to discussion of the SOA workshop report. Manish Shrivastava began by providing an overview of a workshop led by Manish and Joel Thornton and held at PNNL in June of 2015. The subsequent report describing the workshop discussion is now available on the ASR website and the SOA focus group members were asked to comment on the report. As a report on what was discussed at the SOA workshop, the report is in final form. However, a manuscript is currently being prepared based on the workshop report and SOA focus group members, including those who were unable to attend the 2015 workshop, were invited to contribute to that manuscript. The group also briefly discussed the possibility of updating the report as a whitepaper, but decided that contributing to the manuscript was the best path forward. A discussion about the science advances described in the report and which were ready to be incorporated into climate models and which were still the discovery or process level followed.
Jose Jimenez presented several slides outlining areas he felt should be included or updated from the report including: effect of lower temperature on SOA formation, formation of SOA from anthropogenic precursors, and formation of SOA from biomass burning. Neil Donahue commented on the difficulty in understanding wall effects on chamber experiments and therefore understanding the atmospheric relevance of chamber experiments. There was a thorough discussion on how to decide if/when new process-level discoveries should be implemented into climate models. The general consensus was that many of the processes important for SOA formation are still being identified by ASR (and other) researchers and are at a state more appropriate for testing with process and chemical transport models. Only after a more complete understanding is developed should processed be implemented into GCMs. This part of the session ended with a discussion on how to move forward with the manuscript being developed from the workshop report. Several ASR researchers who were unable to attend the workshop expressed interest in contributing to the manuscript and a mechanism was identified to share the manuscript draft in an efficient way so that more scientists could contribute.
Finally, the group discussed ARM measurement needs and concluded that a NO/NOx/NOy instrument and a PTR-MS would help to advance SOA science. The group felt that SGP in particular would benefit from continuous measurements from these instruments.
Needs
The group agreed that a NOx/NOy measurement was needed at the megasites. There was some confusion about whether the NO/NOx/NOy instrument(s) was removed from the list of recommended baseline instruments. In the case it was removed, the group recommends it be included as a baseline instrument, in particular at SGP.Similar to last year, the group also felt that a VOC measurement is necessary to make progress in understanding SOA precursors, formation, and sources. Currently there are no routine VOC measurements at the fixed sites. The PTR-MS associated with the MAOS has typically not been stationed at the fixed sites, at least not so far. Generally the group agreed that PTR-MS would be the best instrument for such measurements and would be particularly useful at SGP as it is the megasite most amenable to studying SOA formation. There was general agreement that making year-round, high-quality measurements with the PTR-MS would require a substantial effort on the part of the instrument mentor, likely beyond what is currently supported by ARM.
Future Plans
The SOA workshop report will be turned into a journal manuscript. The SOA focus group will further contribute to that manuscript. We expect this document could serve as the SOA focus group white paper.Action Items
Scot Martin and Jose Jimenez will organize a Drop Box (or similar) account to facilitate edits and contributions to the SOA workshop report document, which is being turned into a journal paper.Scot or John will send an email to the group soliciting input to the manuscript.