News and Status
Terra was launched on December 18, 1999.
Recent Highlights
- The MOPITT mission will be featured prominently at this year's Fall AGU meeting ( www.agu.org/meetings/fm09 ) in San Francisco (Dec. 14-18, 2009). Nine talks and twelve posters will describe research involving some use of MOPITT data. As part of Terra, NASA's first Earth Observing System platform, the contributions of MOPITT to atmospheric chemistry research will be highlighted in the session titled 'Terra at 10: Our Changing Atmosphere, and Land Surface.' Invited talks in that session by Daniel Jacob, John Gille, and Jim Drummond will review the history and successes of the MOPITT mission, and describe how MOPITT products have enriched our understanding of atmospheric chemistry.
- MOPITT retrievals of CO based exclusively on MOPITT's near-infrared (NIR) channels were recently demonstrated for the first time in a paper by Deeter et al. 2008 (see Publications). The NIR channels are generally more sensitive to CO in the lower troposphere, where most tropospheric CO is generated. The MOPITT Version 5 Product will be the first satellite product for CO incorporating both near-infrared and thermal-infrared measurements.
Announcements
- October 2009: Near the end of October 3, a backup system employing a molecular sieve to control the pressure in one of MOPITT's Length Modulation Cells (LMCs) became unresponsive. The associated LMC is shared by radiometers for Channels 5 and 6. The apparent failure of the sieve heater led to a weak drop in operating pressure from about 68.5 kPa to 65.3 kPa in a span of about six hours. The effect of this pressure drop on the calibrated radiances and retrieval products was quickly evaluated and the data processing software revised accordingly. Comparisons of data products just before and after the failure of the sieve heater exhibit no observable discontinuities. Since Level 2 data products for the period after the sieve heater failure are not yet fully validated, they are currently labeled as 'provisional' and are identifiable with the string 'L2V8.0.8' in the filename (e.g., 'MOP02-20091004-L2V8.0.8.prov.hdf').
- September 2009: After extensive modeling and analysis of the cooler malfunction, MOPITT was restarted on September 28 with slightly reduced amplitude for the displacer unit on the malfunctioning cooler. Following a cool-down period, science-quality data began flowing again on September 30. Analysis of engineering data, calibrated radiances and retrieval products reveal no measurable degradation of the MOPITT products following MOPITT's idle period between July 28 and September 28. No MOPITT products will be available for this period since the instrument was not operating in science mode.
- July 2009: On July 28, one of the two coolers of the MOPITT instrument developed a malfunction causing the instrument to turn itself off. It was soon determined that no permanent damage had been suffered by the instrument but that operating parameters of the malfunctioning cooler would require some adjustments before the instrument could be returned to operations.
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June 2009:
The MOPITT Version 4 product, released as a 'provisional' product in April, is now officially 'validated.' This means that the algorithm used to produce the V4 product is final. V4 validation results will soon be posted on the
Data Products
page. Users will notice that the Level 2 files now include the string 'val' instead of 'prov' (e.g., 'MOP02-20030303-L2V8.0.2.val.hdf' instead of 'MOP02-20030303-L2V8.0.2.prov.hdf').
Processing of the MOPITT Version 3 product will cease on July 31, 2009.
Users of the V4 product should also obtain the latest revision of the Version 4 User's Guide (updated May 28, 2009) on the Publications page. (Significant revisions include a fuller discussion of array dimensioning issues, and a correction in Appendix 7.4 related to the calculation of the total column averaging kernel.) -
April 2009:
The MOPITT Science Team at the National Center of Atmospheric Research announces the availability of the Version 4 product for tropospheric carbon monoxide.
This product is currently 'provisional' and is available both from the
NASA Langley Data Pool
and the
WIST/ECHO system.
New Level 2 and Level 3 (gridded) products are available.
Users of the new V4 product should obtain the new V4 User's Guide available at the
MOPITT website
or through the Langley Data Pool.
Processing of the current V3 product will cease this summer.
The retrieval algorithm used to generate the V4 product benefits from significant advances in radiative transfer modeling, state vector representation, and a priori statistics. Differences between the V3 and V4 products are generally significant and are detailed in the V4 User's Guide. Retrieval performance has been improved in many respects, particularly in regions of very low and very high CO concentrations. Problems with long-term bias drift are also evidently weaker in V4 than in V3. The new V4 product also includes new diagnostics, including the retrieval averaging kernels.