MOPITT Data and Information

• September 2011: MOPITT V5 products for observations made from March, 2000 through the end of 2009 have been reprocessed. After delivering the original V5 L1 and L2 products for this period, MOPITT SIPS personnel became aware of several minor processing problems. First, a software module called the 'Post-preprocessor' had been inadvertently disabled. This code implements a minor correction to the Level 0 data for MOPITT's PMC measurements (Channels 3 and 7). Second, the version of MOPFAS used to process the original V5 product for observations during 2009 was based on slightly inaccurate instrument parameters, producing a small radiance bias in Channel 7 radiances. Finally, it was determined that some MOPITT observations (up to several percent each day) were being discarded based on irrelevant instrument parameters. While the MOPITT team believes these technical problems would only concern a small number of MOPITT data users, these issues could conceivably cause larger problems in the future as the instrument slowly degrades. Filenames of the L1 and L2 products include the processing version number and therefore can be used to distinguish the original (deprecated) V5 products and the reprocessed V5 products. The original L1 filenames included the text string 'L1V3.36' whereas the reprocessed L1 files include 'L1V3.37'. The original L2 filenames included the text string 'L2V10.0' whereas the reprocessed L2 files include 'L2V10.1'.

• June 2011: The MOPITT/NCAR team discovered a data processing error that affects all V4 products previously generated for the period between Sept. 14, 2010 and March 13, 2011, inclusive. As a result, V4 products for this period have been reprocessed and redelivered to the NASA ASDC. Details regarding the cause of the processing error and its effect on the MOPITT products are available on the MOPITT team website.