The MODIS L2 Joint Atmosphere Product (ATM L2) will be produced at the MODAPS facility of NASA Goddard Space Flight Center. MODAPS will produce 100% of the ATML2 product.

Typically 288 ATM L2 HDF files are produced per day, however since some parameters are produced only during the daytime, the nighttime HDF files are considerably smaller than their daytime counterparts.

It should be noted that since both MODIS terminator granules (for both ascending and descending nodes) are counted as day, a full 55% of all MODIS granules are labeled daytime.

With each daytime HDF file roughly 2.9 MB in size and each nighttime HDF file roughly 1.5 MB in size, the total data volume is approximately 650 MB per day.

Production Rules

Run MOD_PRATML2 night and day on each MODIS L2 granule if MOD03, MOD05_L2, MOD06_L2, MOD07_L2 and MOD35_L2 are all present. Otherwise, delay production of this L2 granule until missing ESDTs (among the 5 above) have been either recovered and ingested into MODAPS or determined to be not-available for this processing cycle. Then run if both MOD03 and any of MOD05_L2, MOD06_L2 and MOD07_L2 are present.

Note that MOD04_L2 is also input to MOD_PRATML2, but it is produced (by PGE04) only when the MODIS instrument is in daymode and only for a subset of daytime granules (minimum solar zenith angle < specified threshold). However, MOD04_L2 is never archived without an associated MOD05_L2 product. Thus, "MOD05_L2 present and MOD04_L2 not" implies "MOD04_L2 not produced" (exception is database retrieval error) and the MOD_PRATML2 production rules do not require separate accounting of MOD04_L2.

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Required Input Products
=======================

      MODIS Products:
   ESDT Name    Description
   ---------    -----------
   MOD03        MODIS Terra Geolocation product
   One of MOD04_L2, MOD05_L2, MOD06_L2 or MOD07_L2 
          (see descriptions under Optional Inputs)
 
   Selection Rule:  for all ESDT above
      Choose granule whose RangeDateTime metadata matches the 
      collection period of MODIS output granule.


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Optional Input Products
=======================

      MODIS Products:
                Time Out  
   ESDT Name    (in sec)    Description 
   ---------    --------    -----------
   MOD04        0           MODIS Terra Aerosol product
   MOD05        MODIS Terra Precipitable Water product
   MOD06        MODIS Terra Cloud product
   MOD07        MODIS Terra Profiles product
   MOD35        MODIS Terra Cloud Mask product

   Selection Rule:  MOD04
       Choose granule whose RangeDateTime metadata matches the collection period
       of MODIS output granule.


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Output Products
===============

   ESDT Name    Description
   ---------    -----------
   MODATML2     MODIS Terra Level-2 Joint Atmosphere product (HDF)