Aerosols Working Group

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Revision as of 01:44, 7 May 2015 by Emarais (Talk | contribs) (Organic Aerosol Density (v.10-01))

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All users interested in the GEOS-Chem aerosol simulations are encouraged to subscribe to the aerosols email list (click on the link in the contact information section below).

Information on existing projects and future developments in aerosols will be posted here. We encourage user groups to keep their information up-to-date.

Contact information

Aerosols Working Group Co-Chairs Colette Heald, Jeff Pierce
Aerosols Working Group email list geos-chem-aerosols [at] seas.harvard.edu
To subscribe to email list Send email to geos-chem-aerosols-join [at] seas.harvard.edu
To unsubscribe from email list Send email to geos-chem-aerosols-leave [at] seas.harvard.edu

Current GEOS-Chem Aerosol Projects, alphabetized by institution (please add yours!)

User Group Description Contact Person Date Added
Beijing/SUNY-Albany/L'Aquila Representing GEOS-Chem in the AEROCOM intercomparisons May Fu
Fangqun Yu
Gabriele Curci
28 Jul 2010
Columbia University Multiphase SOA formation in GEOS-Chem Faye McNeill 23 Apr 2015
Dalhousie Simulation of the absorbing aerosol index Melanie Hammer 26 Sep 2012
Dalhousie Aerosol microphysics simulation of AOD and PM2.5 Arjya Sarkar 26 Sep 2012
Dalhousie Arctic aerosol Betty Croft 25 Apr 2015
Dalhousie Satellite-based estimates of Asian PM2.5 Junwei Xu 26 Sep 2012
Dalhousie Assimilation of CALIOP vertical profiles Colin Lee 5 Dec 2013
Dalhousie Satellite-based estimates of Global PM2.5 Aaron van Donkelaar Jun 2010
Harvard Irreversible uptake of isoprene SOA; estimate of organic aerosol yields with satellite observations Eloise Marais 27 April 2014
MIT Examining decadal trends in organic aerosol David Ridley 22 Apr 2015
MIT Investigating uncertainty on aerosol physical & optical properties on AOD, radiative effects, and PM2.5 from space estimates David Ridley 22 Apr 2015
MIT Integrating the reactive carbon budget in GEOS-Chem Sarah Safieddine 22 Apr 2015
MIT Investigating Variability in Ammonia and Impacts on Inorganic PM formation Luke Schiferl 22 Apr 2015
MIT Investigating the impact of land use change on atmospheric composition Sam Silva 22 Apr 2015
MIT Developing a simulation of brown carbon Xuan Wang 22 Apr 2014
MIT Developing a scheme to describe the aging of organic aerosol Qi Chen 8 Apr 2013
MIT/Dalhousie Developing a flexible land use module for GEOS-Chem and investigating the impacts of forest mortality on air quality in the United States Jeff Geddes 22 Apr 2015
MIT/CSU Characterizing the uncertainties in PM2.5 derived from satellite observations Bonne Ford 22 Apr 2015
NASA LaRC transpacific transport of dust and sulfate; composition of Asian upper tropopause aerosol layer (ATAL). Duncan Fairlie 10 Apr 2013
SNU Implement the VBS method in GEOS-Chem for SOA Rokjin Park
Dusung Jo
28 Sep 2012
SNU Siberian forest fire aerosols and climatic effects Rokjin Park
Seungeun Lee
28 Sep 2012
SUNY-Albany Effects of size-resolved aerosol microphysics on aerosol radiative forcing and chemistry Fangqun Yu
Gan Luo
5 May 2015
SUNY-Albany Key processes controlling particle formation and growth in the atmosphere and implications Fangqun Yu
Gan Luo
5 May 2015
UW Sources of sea salt aerosol in polar regions: Blowing snow and Frost flowers Jiayue Huang
Lyatt Jaeglé
22 Apr 2015
UW Sea salt aerosols and their effects on global tropospheric chemistry Lyatt Jaeglé
Jiayue Huang
22 Apr 2015
UW Sulfate formation via oxidation of SO2 by hypohalous acids (e.g., HOBr) Becky Alexander
Qianjie Chen
22 April 2015
University of Wollongong Characterizing interannual variability of Australian dust export and deposition Jesse Greenslade
Jenny Fisher
23 April 2015
L'Aquila Analysis of long-term aerosol optical properties Gabriele Curci 05 May 2015
NIA / NASA LaRC Radiative effects of aerosols versus clouds on key tropospheric oxidants Hongyu Liu 5 May 2015
NIA / NASA LaRC Sources and variability of tropospheric aerosols over the North Atlantic Hongyu Liu 5 May 2015

Recent GEOS-Chem updates related to aerosols

We have added the following updates pertaining to aerosols to recent GEOS-Chem versions:

Version Released Description Contact
v9-02 Mar 2014 Expansion of SOA option (SOA + nonvolatile POA) Havala Pye (formerly Caltech, now EPA)
v9-02 Mar 2014 Cloud water pH for sulfate formation Becky Alexander (U. Washington)
v9-02 Mar 2014 Better representation of OC growth with RH and correction to sulfate optics David Ridley (MIT)
Randall Martin (Dalhousie)
v9-02 Mar 2014 Bug fix in jv_spec_aod.dat for dust species Gabriele Curci (U. L'Aquila)
v9-02 Mar 2014 Update molecular weight of sea salt tracers Colette Heald (MIT)
v9-01-03 Sep 2012 Dust submicron size distribution for optics Dave Ridley, CSU
v9-01-03 Sep 2012 Modifications to sea salt emissions and dry deposition Lyatt Jaegle and Becky Alexander, U Washington
v9-01-03 Sep 2012 Various updates to wet deposition to impact aerosol simulation, see Wet Deposition Further Updates Qiaoqiao Wang, Harvard
v9-01-02 Nov 2011 Implementation of APM aerosol microphysics model Fangqun Yu, SUNY Albany
Gan Luo, SUNY Albany
v9-01-02 Nov 2011 Removing inconsistencies in aerosol diagnostics Sungshik Patrick Kim, Harvard
v9-01-02 Nov 2011 Updated aerosol dry deposition velocities over snow and ice surfaces Jenny Fisher, Harvard
v9-01-02 Nov 2011 Added seasonality to Streets NH3 emissions over Asia Jenny Fisher, Harvard
v9-01-01 Jun 2011 FlexAOD post-processing tool for the community Gabriele Curci, University of l'Aquila

--Melissa Sulprizio 11:14, 17 January 2014 (EST)

On-going Aerosol Working Group Developments

We plan to add these aerosol-related updates to GEOS-Chem in the next few releases:

Update Authors Planned release
Integrating a radiative transfer model into GEOS-Chem Colette Heald (MIT)
David Ridley (MIT)
Karen Cady-Pereira (AER)
Matt Alvarado (AER)
  • Delivered to GCST
  • Slated for inclusion into v10-01
Simplified description of uptake of SO2, nitric acid and sulfuric acid on mineral dust Duncan Fairlie, Langley
  • Delivered to GCST
  • Slated for inclusion into v10-01

--Bob Y. 15:05, 25 April 2014 (EDT)

Future Development Priorities

These are topics which were raised at IGC6 as future updates & development priorities for GEOS-Chem which have not yet been incorporated into the standard code:

Update Authors Priority
Addition of effective wind speed to met fields for consistent resolution dust/sea salt emissions Jeff Pierce (CSU)
David Ridley (MIT)
GCST
medium
Addition of deposition observations to aerosol benchmark Colette Heald (MIT) low
dust simulation expansion (tagged simulation, oxalate, P, Fe chemistry) Matthew Johnson (NC State) low
DMS oxidation scheme updating TBD low
Investigation of how aerosol water is treated in PM comparisons (ISORROPIA vs. hygroscopic growth curves) TBD low
APM capability for nested grid Fangqun Yu (SUNY Albany)
TOMAS capability for nested grid Jeff Pierce (Dalhousie)
Tagged sulfate and nitrate simulation Becky Alexander (U. Washington)
Improved dust simulation in nested-grid model Rokjin Park (Seoul National University)

--Bob Y. 15:04, 25 April 2014 (EDT)

Aerosol optical properties

Please visit our aerosol optical properties wiki page for more information about:

  1. Description of GEOS-Chem aerosol optics
  2. Aerosol optical properties update for v8-03-01
  3. Aerosol optical properties at high spectral resolution

Here is a list of updates that were considered when this was last reviewed in 2010 (2, 4 and 5 are included in the v8-03-01 update):

Proposed Update (include information on old values if known) Reference Contact
Account for absorption in the 300-500 nm range by OC, which may be greater than presently treated. Currently we have OC ss albedo in this range being > 0.95, though it may be lower than 0.85. Barnard et al, 2008 Daven Henze
Expand Mie table to include more wavelengths. Most literature values compare at 500 or 550 nm. Current GC lookup table includes 400, then 600. A wider range is also necessary for integrating to get total SW flux; something greater than 1500 perhaps? Martin et al, 2004 Daven Henze
Consider using the water content of the fine mode aerosol calculated in the aerosol thermodynamic module rather than hygroscopic growth curves to estimate wet particle effective radius. N/A Daven Henze
Consider changing the "default" AOD diagnostic wavelength from 400 nm to 550nm (for matching with MODIS & CALIPSO) N/A Colette Heald
Treat the radius of hydrophylic organic aerosol similar to that of sulfate. This is based on observations that organic aerosol and sulfate are often internally mixed. Should we consider something similar for black carbon? Rupkheti et al., 2007 Randall Martin


Additional updates to aerosol optics since v8-03-01:

Update Version Number Contact
Overhaul of AOD diagnostics v9-01-02 Patrick Kim (Harvard)
Dust submicron size distribution for optics v9-01-03 David Ridley (CSU, now MIT)
Bug fix in jv_spec_aod.dat for dust species v9-02 Gabriele Curci (l'Aquila)
Update jv_spec.dat and jv_spec_aod.dat with better representation of OC growth with RH and correction to sulfate optics v9-02 Dave Ridley (MIT) and Randall Martin (Dalhousie)

Related Topics

Issues / Topics for Discussion

Organic Aerosol Density (v.10-01)

The organic aerosol density (1800 kg/m3) for calculating aerosol optical depth in aerosol_mod.F, based on Hess et al. (1997), is outdated and not representative of organic aerosols. The value is for a generic water soluble aerosol that could include sulfate, nitrate, SOA etc. Instead, we suggest GEOS-Chem users replace this with a density of 1300 kg/m3. There are numerous references that corroborate this value, or a value between 1200-1400 kg/m3. There are too many to list, but see for example p. 5174-5175 of Hallquist et al., ACP, 2007.

To make the change in aerosol_mod.F simply replace MSDENS(3) = 1800 with MSDENS(3) = 1300 in the RDAER subroutine. This leads to a 40% increase in organic carbon AOD.

Update by Eloise Marais (Harvard) and Melanie Hammer (Dalhousie).

--Emarais 21:06, 6 May 2015 (EDT)