Climate Data

AIRS (Atmospheric InfraRed Sounder): Version 6 Level 2

AIRS Version 6 Level 2 data represent a significant improvement over AIRS Version 5 Level 2 products in terms of greater stability, yield, and quality. Several algorithmic improvements have been made by the AIRS Project in conjunction with the AIRS Science Team. Improvements include: (a) Improved soundings of Tropospheric and Sea Surface Temperatures, day and night; (b) Improvements are larger with increasing cloud cover; (c) Improved retrievals of surface spectral emissivity, day and night; (d) Most of the spurious temperature bias trend seen in earlier versions has been removed; (e) Substantially improved retrieval yield (number of soundings accepted for output) for climate studies; (f) AIRS-Only retrievals with comparable accuracy to AIRS/AMSU retrievals; and (g) More realistic hemispheric seasonal variability and global distribution of Carbon Monoxide. Retrievals from AIRS are being used as a component of the Collaborative Climate Model and Observational Data Services (CCMODS) project to identify and correct biases in modeled physical processes occurring at many spatial or temporal scales.

Three of the significant changes for the Version 6 L3 data include:

  • L3 support products which contain profile data at 100 vertical levels are now available.
  • A TqJoint grid is available, which contains gridded data for a common set of temperature and water vapor observations.
  • Water vapor and trace gas products are now reported both as layer and level quantities.

Key Strengths:

  • High resolution (13km at nadir)

Key Limitations:

  • Individual satellite swaths can be noisy.

Years of Record

2002/08 to 2016/09
temporal metadataID:




Data Time Period Extended?

yes, data set is extended


Vertical Levels

Data Access: Please Cite data sources, following the data providers' instructions.

Key Figures

Click the thumbnails to view larger sizes



Climate Data Guide Image: AIRS AIRS Level 2 quick browse image for Jan. 7, 2013
Climate Data Guide Image: AIRS A side-by-side comparison of Version 5 PCldTopStd and Version 6 PCldTop shows the improved resolution of the AIRS Cloud retrieval in Version 6 which is now at the AIRS resolution (~13 km) rather the AMSU resolution (~45 km). Source:
These figures show a side-by -side comparison of AIRS NRT Version 5 (left panel) and Version 6 (right panel) total column CO converted to mixing ratio. Source:

Cite this page

National Center for Atmospheric Research Staff (Eds). Last modified 29 Sep 2017. "The Climate Data Guide: AIRS (Atmospheric InfraRed Sounder): Version 6 Level 2." Retrieved from

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