Please find a new version of the Harvard point model calculations for
the DC-8 in your incoming directory. These are two files: one for the 1
minute merge, one based on the HNO3 merge. A third one based on the NMHC
merge is currently in progress, and I hope to do some P-3B runs soon.

    These new files replace *all* the old files which are currently in the
archive. There have been several changes, both in the results and in the
format:

   - as Jim Crawford noticed, some water vapor values once again did not
get converted correctly from g/kg to ppmv. This has now been corrected and
does change the results.

   - the initial data coverage criterion of 65% applied to the 1 minute
merge has been reduced to 25%. This results in additional ~700 model
points.

   - flight 3 has now been included in the modeling efforts.

   - the time step of the model calculations was decreased from 60 minutes
to 30 minutes.

   - instantaneous results and 24h averages are now combined in one file.
The 24h averages are marked with a trailing '(24h)'.

   - the data set contains several cases where evaluation of the NOx
budget is not feasible, because PAN and/or HNO3 were interpolated or set
to default values from a median profile. Therefore, the analysis of the
NOx budget should be restricted to cases where PAN and HNO3 are not
missing (to distinguish the actually observed values from the interpolated
model input values, the latter are marked 'i'+name, i.e. iPAN and iHNO3).

   - the REGION variable is no longer available. You can find a program to
compute the REGION values on our webpage
          http://www-as.harvard.edu/chemistry/trop/pem-t/model.html

This program is written in IDL but should be easily adapted to other
languages. The description of the "Harvard regions" is contained in the
program file.

   - here is a copy of the information on stratospheric encounters:
Listed below are the time intervals where the DC-8 was encountering
stratospheric air (sufficiently extended in order to be on the safe side):
   flight 09  :  UTC time  64620 - 67800
   flight 13  :            78060 - 81360
   flight 19  :            92520 - 95400
As diagnostics I used O3, CO, altitude (and NO)
These time intervals should be excluded from any regional analysis of
tropospheric data.



Please note that the model product is also available from 
          http://www-as.harvard.edu/chemistry/trop/pem-t/model.html


Thanks,
Martin.


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Dr. Martin Schultz                   
Department for Earth&Planetary Sciences, Harvard University
186 Pierce Hall, 29 Oxford St., Cambridge, MA-02138, USA

phone: (617)-496-8318
fax  : (617)-495-4551

e-mail: mgs@io.harvard.edu
IDL-homepage: http://www-as.harvard.edu/people/staff/mgs/idl/
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