Chemistry Working Group

All users interested in the GEOS-Chem chemistry scheme and associated processes (photolysis, heterogeneous, deposition) are encouraged to subscribe to the chemistry email list (click on the link in the contact information section below).

Contact information

Oxidants and Chemistry Working Group Co-Chairs	Barron Henderson (GitHub: @barronh) Lu Hu (GitHub: @luhu0) Jingqiu Mao (Github: @jingqiumao)
Oxidants and Chemistry Working Group email list	geos-chem-oxidants [at] g.harvard.edu
To subscribe to email list	Either Send an email to geos-chem-oxidants+subscribe [at] g.harvard.edu Or Go to the GEOS-Chem Oxidants and Chemistry Click on Subscribe to this group
To unsubscribe from email list	Either Send an email to geos-chem-oxidants+unsubscribe [at] g.harvard.edu Or Go to the GEOS-Chem Oxidants and Chemistry Click on the My Settings button Click on Leave this group

--Bob Y. (talk) 18:29, 21 August 2015 (UTC)

Current GEOS-Chem Chemistry Projects (please add yours!)

User Group	Description	Contact Person	Date Added
NASA LARC	Scheme for higher PN production from aromatics, MEK, monoterpenes, glycolaldehyde, and 1,3-butadiene	Katherine R. Travis	19 Sep 2023
Columbia University	Automated model reduction isoprene oxidation mechanism	Benjamin Yang Dan Westervelt	12 Sep 2023
NOAA CSL	JPL Kinetic Review Update/C-N balance/stoichiometry update	Kelvin Bates	01 Jul 2023
University of York	Nitrate Photolysis	Mat Evans Matthew Rowlinson	08 Jun 2022
University of York	Halogen reverse reactions	Mat Evans Hansen Cao	01 Jun 2022
University of York	Chlorine chemistry	Mat Evans Amy Lees	01 Oct 2022
Harvard University and MPIC-Mainz	Further development of The Kinetic PreProcessor (KPP)	Bob Yantosca (GCST)	03 Jun 2022
Harvard University	Adding an adaptive solver capability into KPP	Haipeng Lin	03 Jun 2022
GCST	Migrating the Hg chemistry mechanism to KPP	Bob Yantosca (GCST)	03 Jun 2022
GCST	Adding a CO-CO2-CH4-OCS chemistry mechanism with KPP	Bob Yantosca (GCST)	03 Jun 2022
U Montana	Formic acid and acetic acid formation in fire smoke	Wade Permar Lu Hu	21 May 2022
U Montana	Furans chemistry in MCM and in GEOS-Chem	Lixu Jin Lu Hu	21 May 2022
U Wollongong	Evaluation of aromatic oxidation products using new observational constraints	Stephen MacFarlane	9 June 2022
UNSW, Sydney	Contribution of the unexplored photochemistry of aldehydes to the tropospheric levels of hydrogen	Maria Paula Perez-Pena	25 June 2021
University of California, Riverside	Updates to DMS oxidation scheme	William Porter	26 August 2020
Harvard University	Overhaul of cloud pH code including: use of Newton's method and addition of crustal cations and organic acids	Viral Shah Jonathan Moch	5 May 2019
U Alaska Fairbanks	Monoterpene oxidation and its impact on SOA formation	Yiqi Zheng Jingqiu Mao	21 April 2019
MIT	Simulating the global reactive carbon budget	Sarah Safieddine	12 April 2017
FSU	Stratosphere-troposphere coupling, improvements to UCX & H2 chemistry	Chris Holmes	May 2017
FSU	Methane and methyl chloroform lifetimes	Chris Holmes	May 2017
FSU	Arctic halogen & ozone chemistry	Chris Holmes	May 2017

Current GEOS-Chem Chemistry Issues (please add yours!)

Working group telecom on the 13/3/2019

There was a telecon to discuss issues with the chemistry. The notes from the meeting are here Media:Chemistry_WG_March_2019..pdf . Mat Evans

Carbon balance

Script for evaluating carbon balance

Barron Henderson wrote:

[I created] an evaluation script to preserve balances going forward as the mechanism evolves (e.g., as isoprene gets updated).

Currently, this done using an off-line script described in a linked note. The approach is pretty straight-forward, but could be expanded to check conservation of functional groups as suggested by Mat.

Longer term, the same technique would ideally be built-in to the standard KPP as an optional report. I discussed it with Michael Long and we both think that KPP has most of the capability for atom conservation (if not all). It may simply be a matter of defining the chemical formulas in the *.spc file.

--Melissa Sulprizio (talk) 21:06, 22 May 2017 (UTC)

JPL Released 18th Rate Coefficient Evaluation

This update was included in v11-02a and approved on 12 May 2017.

JPL has released its 18th evaluation of chemical rate coefficients for atmospheric studies (Burkholder et al., 2015)." A new page (Updates in JPL Publication 15-10) is being created to compare rates between GEOS-Chem v10 and JPL Publication 15-10.

J. B. Burkholder, S. P. Sander, J. Abbatt, J. R. Barker, R. E. Huie, C. E. Kolb, M. J. Kurylo, V. L. Orkin, D. M. Wilmouth, and P. H. Wine "Chemical Kinetics and Photochemical Data for Use in Atmospheric Studies, Evaluation No. 18," JPL Publication 15-10, Jet Propulsion Laboratory, Pasadena, 2015 http://jpldataeval.jpl.nasa.gov.

---B. Henderson 2016-05-03 15:25 (EDT)

Working Group Tele-con on the 2nd December 2011

ChemTelecon20111202 Mat Evans

Isoprene chemistry

I've created a page with some of the recent literature on isoprene chemistry. Please add more papers as they come along! ( MJE Leeds)

HO2 + CH2O

Scheme does not contain the HO2 + CH2O --> Adduct reaction (MJE Leeds)

Hermans, I., et al. (2005), Kinetics of alpha-hydroxy-alkylperoxyl radicals in oxidation processes. HO2 center dot-initiated oxidation of ketones/aldehydes near the tropopause, Journal of Physical Chemistry A, 109(19), 4303-4311.

According to this paper, this reaction is significant when Temperature is below 220K.

--J Mao. 15:00, 10 Aug 2009 (EDT)

Previous issues that have now been resolved

Centralizing chemistry time step

This update was tested in the 1-month benchmark simulation v9-01-02q and approved on 18 Oct 2011.

Please see the full discussion on the Centralized chemistry time step wiki page.

--Bob Y. 16:01, 4 November 2011 (EDT)

Acetone photolysis

This discussion has been moved to our FAST-J photolysis mechanism wiki page.

--Bob Y. 15:20, 20 May 2014 (EDT)

Documentation

• Updated chemical reactions that will be used in GEOS-Chem v8-02-04 and higher.
• Updated chemical reactions now used in GEOS-Chem v8-02-01 through GEOS-Chem v8-02-03.
  • All typos have now been corrected in the present file.
• Format of FAST-J input file jv_spec.dat

--Bob Y. 15:41, 27 October 2009 (EDT)