Chemistry Working Group
Oxidants and 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).
- 1 Contact information
- 2 Current GEOS-Chem Chemistry Projects (please add yours!)
- 3 Current GEOS-Chem Chemistry Issues (please add yours!)
- 4 Previous issues that have now been resolved
- 5 Documentation
|Oxidants and Chemistry Working Group Chair||Mat Evans|
|Oxidants and Chemistry Working Group email firstname.lastname@example.org|
|To subscribe to email list||Send email to email@example.com|
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Current GEOS-Chem Chemistry Projects (please add yours!)
|User Group||Description||Contact Person||Date Added|
|Caltech/Harvard||Examining the effects of isoprene nitrates and epoxide on tropical ozone and OH using SHADOZ and OMI measurements||Fabien Paulot
|April 28, 2009|
|Caltech/Harvard||Examining the HCHO yield, OH recycling and ozone production with INTEX-A observations from new isoprene chemistry||Jingqiu Mao
|April 28, 2009|
|NIA / LaRC||Tropospheric ozone over East Asia: Ozonesonde observations and modeling analysis||Yiqiang Zhang
|June 29, 2010|
|U. Wollongong||Tropospheric ozone precursors over Australasia: Using GEOS-Chem to interpret FTIR measurements of CO, NO2 and HCHO||Rebecca Buchholz||May 19, 2011|
Current GEOS-Chem Chemistry Issues (please add yours!)
I've created a page with some of the recent literature on isoprene chemistry. Please add more papers as they come along! ( MJE Leeds)
rate of HNO4
Ellie Browne found a typo in the globchem.dat (v8-02-01 and beyond)
A 73 9.52E-05 3.2E+00 -10900 1 P 0.60 0. 0. 1.38E+15 1.4E+00 -10900 0 0.00 0. 0. HNO4 + M =1.000HO2 +1.000NO2 + +
This should be corrected as:
A 73 9.52E-05 3.4E+00 -10900 1 P 0.60 0. 0. 1.38E+15 1.1E+00 -10900 0 0.00 0. 0. HNO4 + M =1.000HO2 +1.000NO2 + +
The difference is within 2%.
--J Mao. 19:04, 30 Aug 2010 (EDT)
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
yield of isoprene nitrates
Fabien Paulot found a problem in current chemistry scheme. In GEOS-Chem v8-02-01 and beyond, isoprene nitrates are produced twice: one through channel A and one through 10% loss in channel B. This makes the loss of NOx larger than it should be (18.7% vs. 10%) and also reduces the yield of MVK/MACR/CH2O by about 13%.
A 453 2.70E-12 0.0E+00 350 1 B 0.00 0. 0. 5.00E+00 0.0E+00 0 0 0.00 0. 0. RIO2 + NO =0.900NO2 +0.900HO2 +0.340IALD +0.340MVK +0.220MACR +0.560CH2O + + A 453 2.70E-12 0.0E+00 350 1 A 0.00 0. 0. 5.00E+00 0.0E+00 0 0 0.00 0. 0. RIO2 + NO =1.000HNO3 + + +
So it should be corrected as (no channel A):
A 453 2.70E-12 0.0E+00 350 0 0 0.00 0. 0. RIO2 + NO =0.900NO2 +0.900HO2 +0.340IALD +0.340MVK +0.220MACR +0.560CH2O + + D 453 2.70E-12 0.0E+00 350 1 A 0.00 0. 0. 5.00E+00 0.0E+00 0 0 0.00 0. 0. RIO2 + NO =1.000HNO3 + + +
Potential issue with reading restart.cspec file
This update was tested in the 1-month benchmark simulation v9-01-02c and approved on 21 Jul 2011.
Jingqiu Mao discovered a mis-indexing problem when using the restart.cspec.YYYYMMDDhh file. Please see this wiki post for more information.
--Bob Y. 16:02, 4 November 2011 (EDT)
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)
- 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)