Please read all of this file before using any of our AIRS datafiles.
If you have questions, comments, or suggestions, please e-mail me,
           
               Dr. W. Wallace McMillan, mcmillan@umbc.edu.

This directory contains NetCDF files of 1x1 degree gridded AIRS CO retrievals.
Only good AIRS retrievals were used, and the AM and PM orbits are saved
separately.  Only the retrieved mixing ratio at 500 mb and the total column CO 
are provided.  These preliminary files were produced from our near-real-time 
procesing, and thus only the MILAGRO or INTEX-B study area are included in 
the grid.  Detailed data files with all good AIRS retrievals of CO, O3, H2O, 
and T will be provided in September 2006.  Global coverage will be available
with reprocessing in the Fall of 2006.

All these retrievals were processed at UMBC with v4.2 of the AIRS research 
retrieval code developed by Dr. Chris Barnet (NOAA/NESDIS).  We will be glad 
to assist you with your analysis and provide our expertise to help interpret 
any profiles of interest to you.

This is an interim product which will be superceded in late 2006 by a final
reprocessing with v5.0 of the AIRS Team Retrieval code.  As an interim 
product, the pre-launch AIRS CO retrieval algorithm was used with the AFGL
first guess CO profile.

The following variables are contained in each file (the number of "good" 
retrievals, = nobs, varies from day to day). 


  COlat          latitude at the center of each 1x1 bin (nlat,nlon)
  COlon          longitude at the center of each 1x1 bin (nlat,nlon)
  COppbv         AIRS retrieved CO mixing ratio in ppbv in each 1x1 bin 
                     (nlat,nlon)
  COtcol         AIRS retrieved total column CO in molecules/cm2 in each 
                     1x1 bin (nlat,nlon)
  Day            Day of the month of observation
  Latitude       Latitude array (nlat)
  Longitude      Longitude array (nlon)
  Month          Month of the year of observation
  Psurf          average surface pressure (from ECMWF) in mb in each 1x1 bin
  Year           Year of AIRS observation
  ans            cell array of variable names

The total column CO varies with the surface pressure, so columns over high
terrain will normally be smaller due to the decreased depth of atmosphere.
The array size of COppbv and COtotcol match COlat and COlon so MATLAB matrix
map commands can be used to speed up plotting of maps.

W. Wallace McMillan, 8/31/06