# Presentation: 003374

## Gas-Particle InteractionsWorking Group Summary

- Atmospheric Science Program Annual Meeting
- Alexandria, VA
- November 1, 2005

**Rahul Zaveri**
**Pacific Northwest National Laboratory**

## Attendees			Affiliation

- Michael Alexander		Pacific Northwest National Laboratory
- Paul Davidovits		Boston College
- Mike Ezell			University of California at Irvine
- Barbara Finlayson-Pitts	University of California at Irvine
- Mary Gilles			Lawrence Berkeley Laboratory
- Jose Jimenez		University of Colorado, Boulder
- Larry Kleinman		Brookhaven National Laboratory
- Chuck Kolb		Aerodyne Research, Inc.
- Alex Laskin		Pacific Northwest National Laboratory
- Sasha Madronich		NCAR
- Luisa Molina		University of California at San Diego
- Jay Slowik			Boston College
- Stephen Springston	Brookhaven National Laboratory
- Judy Weinstein-Lloyd	SUNY Old Westbury
- Rahul Zaveri, Chair		Pacific Northwest National Laboratory
- Paul Ziemann		University of California, Riverside

## Characterization of secondary organic aerosol precursors, formation, 
and processing:
Field measurements of SOA and other species using AMS. [Jimenez]
Field measurements of secondary organic aerosols (SOA) and their precursors using the PTR-MS and AMS. [Alexander]
Rate constants of reactions of key oxidants with various particulate organic compounds, and their effects on hygroscopicity, CCN activity, and volatilization of reacted particles. [Ziemann]
Characterization of laboratory and field collected organic particles to produce structure-physical (hygroscopic and optical) properties relationships for SOA and nitrate particles. [Finlayson-Pitts]
Field measurements of chemical content of SOA, its precursors, and oxidants using DOAS, Aerodyne Mobile Laboratory, and a suite of other ground-based instruments. [Molina, Kolb]
Field measurements of SOA with the G-1 [Kleinman, Berkowitz/Zaveri]
Data sets from aircraft flights during ASP field campaigns of core chemical and aerosol properties. [Springston, Lloyd, Hubbe]

***and processing***:
- Field measurements of SOA and other species using AMS. [Jimenez]
- Field measurements of secondary organic aerosols (SOA) and their precursors using the PTR-MS and AMS. [Alexander]
- Rate constants of reactions of key oxidants with various particulate organic compounds, and their effects on hygroscopicity, CCN activity, and volatilization of reacted particles. [Ziemann]
- Characterization of laboratory and field collected organic particles to produce structure-physical (hygroscopic and optical) properties relationships for SOA and nitrate particles. [Finlayson-Pitts]
- Field measurements of chemical content of SOA, its precursors, and oxidants using DOAS, Aerodyne Mobile Laboratory, and a suite of other ground-based instruments. [Molina, Kolb]
- Field measurements of SOA with the G-1 [Kleinman, Berkowitz/Zaveri]
- Data sets from aircraft flights during ASP field campaigns of core chemical and aerosol properties. [Springston, Lloyd, Hubbe]

**Laboratory and Field Measurements Useful for Developing, Constraining, and Evaluating Models**

## Laboratory and Field Measurements Useful for Developing, Constraining, and Evaluating Models

***Characterization and aging of black carbon (BC), mineral, and other ***
***ambient particles***:
- Characterization of BC particles with near-edge x-ray absorption spectra for BC surrogates, atmospheric particles containing soot/BC, and samples that do not contain BC; and determine if x-ray microscopy imaging can be used to quantify the mixing state of BC particles. [Gilles]
- Chemical, hygroscopic, and morphological characterization of bulk and individual particles (laboratory and field samples) containing BC, minerals, and other components using a variety of microscopic and spectroscopic techniques. [Laskin]
- Physical and chemical properties of BC particles subjected to surface oxidation and coating with organic and inorganic species. [Davidovits]

## Model Development, Improvement and Evaluation

***Development and evaluation of improved process models using***
***laboratory and field measurements***
- Fully-explicit mechanisms for secondary organic aerosol (SOA) formation along with a repository of measured and estimated kinetic, mechanistic, thermodynamic, and spectroscopic data. [Madronich]
- Comprehensive SOA representation in MOSAIC aerosol module and evaluation using laboratory and field measurements [Madronich, Zaveri]
- Size- and composition-resolved gas-aerosol Lagrangian box-model incorporating laboratory findings on SOA formation, BC aging, and heterogeneous chemistry  [Zaveri]

## Path Forward

***Model development and evaluation will require close collaboration ***
***between modelers and experimentalists (lab and field).***
- Need to integrate laboratory findings into models.
- Need to interface with other working groups better.
- Time-resolved Lagrangian G-1 flights are needed in MAX-Mex and MAX-Tex for constraining and evaluating gas-particle process models of aerosol formation, evolution, and aging.
- Ground measurements at T0, T1, T2 in MAX-Mex will be also useful for evaluating aerosol evolution and aging processes.
- Propose a workshop on SOA measurements and modeling sometime late 2006?