NOx-Ox-HC-aerosol
From Geos-chem
Contents
CH4 concentrations
Chris Buten (cbuten@pdx.edu) wrote:
- When running the NOxOxHC simulation, I presume that CH4 concentration is specified as an input and not determined by emissions and transport (and therefore not a tracer). If so, is there a way to easily visualize or extract these input concentrations?
Bob Yantosca (yantosca@seas.harvard.edu) wrote:
- Yes, in the full chemistry mechanism, CH4 is a constant. The values for years and latitude bands are set by routine get_global_ch4.f.
--Bob Y. 09:52, 14 July 2008 (EDT)
FAST-J Photolysis
NOTE: This discussion has now been moved to the Photolysis mechanism page.
Variable Tropopause
25-Sep-2007
- Note that the implementation of the variable tropopause is buggy in versions prior to GEOS-Chem v7-04-12. If you are using versions prior to v7-04-12, you should turn the variable tropopause OFF.
- Jennifer Logan (see correspondence below) suggested that we should cap the variable tropopause at 200hPa in near-polar regions (90-60S and 60-90N), to avoid the problem with anomalously high tropopause heights at high latitudes. This fix was not in v7-04-12, but will be implemented into GEOS-Chem internal version v7-04-13.
- Jennifer Logan (jlogan@seas.harvard.edu) wrote:
- After looking at the two papers I sent, I think we should restrict the tropopause at latitudes > 60 deg. to pressures greater than 200 mb (about 11 km). From Fig. 3 in Seidel and Randel, there are tropopause (TP) heights as high as 13.5 km in the Antarctic (median height is ~9.8 km, 250 mb), but I don't think we want to be doing trop. chem there. The median TP pressure at ~80 N is ~300 mb, compared to ~250 mb at 70-85 S. The extratropical TP heights are higher (lower pressure) in the SH than in the NH according to Fig. 3.
- This approach is also very easy to explain in a paper.
- Jennifer
Other errors in SMVGEAR
- Click HERE for a description of the SMVGEAR bug that caused concentrations of certain tracers in STT to go to zero. This bug was fixed by May Fu and Philippe Le Sager.
- Lok Lamsal reported a bug with NaN's in SMVGEAR. Bob Yantosca recommended a fix for this error. Click HERE to visit the discussion in the Bug Fixes Forum.