Breakout Summary Report


ARM/ASR User and PI Meeting

Aerosol Processes Working Group Meeting
27 October 2022
2:00 PM - 5:00 PM
Nicole Riemer and Jim Smith

Breakout Description

The Aerosol Processes Working Group focuses on understanding of processes that control spatial and time-related distribution of aerosols and their chemical, microphysical (occurring on a microscopic scale), and optical properties. The goal is to reduce the uncertainty in radiative forcing (energy imbalance) due to these atmospheric particles. Research areas include: 1) new particle formation; 2) effects of aerosol composition, mixing state, and physical properties on growth, aging, and removal processes; 3) direct and indirect radiative effects of optically absorbing aerosols; and 4) understanding and predicting secondary organic aerosol concentrations and properties.

Main Discussion

Our goal for the session was to provide a forum for summarizing and highlighting ongoing work related to aerosol processes within the ARM facility/ASR program. This included research results from current projects, updates regarding ongoing and planned field campaigns, updates from our Aerosol Translator and from the Aerosol Measurement Science Group.
The session started off with an introduction by Jim Smith. He presented an overview on current research areas in the working group, gave a brief overview of recent and planned ARM field deployments with an “aerosol processes” component, and introduced the new Aerosol Processes Working Group co-chair Markus Petters.
We then had 30 minutes of “1-min madness” presentations by working group members. 23 presentations were made.
Next, the Aerosol Translator, John Shilling, gave a short overview of aerosol-related data products and value-added products (VAPs). Some of these were motivated through discussions with the working group over the past years. New available data products are the merged size distribution VAP, which creates a single mobility size distribution with TSI-SMPS bin structure from the SMPS and APS data; the CCN vertical profile VAP, which estimates the vertical distribution of CCN as a function of supersaturation; the aerosol optical depth best estimate VAP, which combines AOD measurements from multiple instruments; the CCN kappa VAP, which uses CCNC and SMPS measurements to parameterize hygroscopicity using Kappa-Kohler Theory; the ACSM corrected mass VAP, which provides high-quality data in near-real time for all sites with an ACSM (including ToFs) and applied the composition-dependent collection efficiency calculation from Middlebrook et al. 2012 to the autonomous ACSM b1 data; and two baseline VAPs for AOD and AOP. Plans for FY 2023 are to process more data for the newly introduced VAPS, maintain real-time processing for the ACSM data, and explore using aethalometer absorption data (instead of PSAP) for the AOP VAP.
This was followed by breakout session summaries: Eastern Pacific Cloud Aerosol Precipitation Experiment (EPCAPE) by Lynn Russell, Surface Atmosphere Integrated field Laboratory (SAIL) Campaign by Daniel Feldman, Shortwave-absorbing aerosols and their interactions with clouds, by Paquita Zuidema, TRACER updates, and updates about the Southeast U.S. AMF3 deployment by Chongai Kuang. Since the plans for the Southeast U.S. AMF3 deployment are still being finalized, the group discussed ideas for additional instrumentation to deploy to answer specific science questions.
We ended the meeting with a summary from the Aerosol Measurement Science Group by Gannet Hallar and Tim Onasch. This group coordinates ARM infrastructure, measurements, and data products of aerosols and trace gases with the scientific objectives of improving climate science and model forecasts. This group is now organized in four subgroups (Measurement Techniques (lead: Allison McComiskey), Measurement Quality (lead: Rich Moore), Measurement Modeling (lead: Jerome Fast), and Measurement Sampling (Jim Smith). We discussed the ARM super-site sampling strategy, which envisions structured intensive operational periods with the goal to support small campaigns associated with annual facility call campaigns, increase in spatial (i.e., vertical) and temporal (i.e., 4D) measurements, and increase in direct modeling efforts.

Key Findings

After the meeting, we sent a short survey to the aerosol processes working group to obtain their feedback on the meeting. One question was “How satisfied were you with the Aerosol Working Group Session on Thursday afternoon?”. We had 21 responses, 45% reported “very satisfied”, 35% reported “satisfied”, and 20% reported “did not attend the WG session”.







Future Plans

The co-chairs will coordinate communication with the WG throughout the year.

Action Items