GEOS-Chem v9-01-02 benchmark history

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On this page we have posted complete information about all benchmark simulations (both 1-month and 1-year) for GEOS-Chem v9-01-02.


Here is the assessment form for 1-month benchmark simulation v9-01-02a.

New features added into GEOS-Chem:
Developer name(s) and institution(s):
  • Dynamic tropopause fix: Daven Henze (Colorado University) and Jamin Koo (MIT)
  • Out-of-bounds error: GEOS-Chem Support Team
Version, resolution, met fields used: v9-01-02, GEOS-5 (47L), 4x5
1-month benchmark finished on: Mon Jun 13 18:02:07 EDT 2011
Compared to previous benchmark: v9-01-01
This update will impact:
(select all that apply with boldface)
Advection, BL Mixing, Convection, Met Fields, Dry Dep, Wet Dep, Stratosphere, Anthro Emiss, Biogenic Emiss, Biomass Emiss, Photolysis, Chemistry, Other (please specify): Tropopause
Plots may be viewed at:
Global mean OH (from log file): 13.1877841861589 x 105 molec/cm3
Methyl chloroform lifetime: 4.7490 years
Did either of these change by more than 5%? No
At the SURFACE, list all species that changed by 10% or more: None
Comments on SURFACE differences: None
At 500 hPa, list all species that changed by 10% or more: NIT, NH3
Comments on 500 hPa differences: Follow up calculations indicate that these changes are owing to an unresolved OpenMP issue, not the v9-01-02a code updates. NIT seems particularly sensitive to this issue, and this probably drives changes in NH3.
In the ZONAL MEAN PLOTS, list all species that changed by 10% or more: NOx, N2O5, NIT, NH3
Comments on ZONAL MEAN differences:
  • Small changes in tropospheric OH on order of +/-0.05%.
  • NOx changes follow from the variable tropopause fix and are small in absolute value.
  • There are also small percent changes for most gas-phase species near the tropopause.
  • The changes to NIT and NH3 have a random structure with large (>1000%) differences in spots throughout the troposphere, likely owing to the issue mentioned above. However, absolute changes are still small.
  • There are small (a few percent or less) changes visible for all chemically active gas and aerosol species. These changes are likely owing to both the code updates and the random OpenMP error, with the former having structure around the tropopause and the latter contributing to random scatter throughout the troposphere.
In the EMISSION RATIO maps, list all species that changed by 10% or more: None
Comments on EMISSION RATIO differences: No changes in emissions.
Additional or summary comments:
  • There is an unidentified OpenMP error which contributes to differences shown here, as confirmed by independent tests of consecutive evaluations of a single executable compiled with and without parallelization. The impacts of this OpenMP error are typically less than a fraction of a percent, and negligible in terms of absolute value, with the exception of NIT and NH3. This is an issue to investigate further.
  • I think this code update obfuscates the need to copy CSPEC to CSPEC_FULL and back when variable tropopause is turned on, as this fix now recalls the proper mapping from the previous time step when performing partitioning. Perhaps a future update could clean this up.
Requires further investigation: See above
Approved: Daven Henze
Date of approval: 06/28/2011

--Bob Y. 15:06, 23 June 2011 (EDT)