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MEaSUREs SeaWiFS Deep Blue Version 4 Aerosols Release

Version 4 of Long-Term Aerosols over Land and Ocean from SeaWiFS (also known as “SeaWiFS Deep Blue”) now available at GES DISC

MEaSUREs SeaWiFS Deep Blue Version 4 Aerosols Release

Figure 1: Sample images of monthly climatology aerosol optical thickness at 550nm for April (upper) and October (lower). Images are generated with Giovanni.

MEaSUREs SeaWiFS Deep Blue Version 4 Aerosols Release

The Goddard Earth Sciences Data and Information Services Center (GES DISC), in collaboration with Principal Investigator Dr. Christina Hsu, is pleased to announce the release of an updated version (Version 4) of data products from the "Consistent Long-Term Aerosol Data Records over Land and Ocean from SeaWiFS" project. This project is part of the NASA Making Earth Science Data Records for Use in Research Environments (MEaSUREs) Program. These products cover the period from September 4, 1997, to December 11, 2010. 

Table 1: List of Products
 Product Shortname
Spatial Resolution
Average File Size (MB)
 Level 2, swath
13.5 x 13.5 km2
 L3 daily, grid
0.5o x 0.5o
 L3 daily, grid
1.0o x 1.0o
 L3 monthly, grid
0.5o x 0.5o
 L3 monthly, grid
1.0o x 1.0o
 L3 monthly climatology, grid (new product)
0.5o x 0.5o
 L3 monthly climatology, grid (new product)
1.0o x 1.0o


Version 4 data represent significant improvements over the previous version, and it is recommended that all users upgrade as soon as possible. The improved over-land algorithm is documented in Hsu et al., (2013), and the ocean algorithm is based on Sayer et al., (2012). Improvements from Version 3 to Version 4 are also listed in the product README and are summarized as follows:

  • Improved turbid water filter;
  • Improved aerosol models over regions with highly absorbing aerosols;
  • Updates to QA-filtering during L3 aggregation;
  • Fixed a minor coding error in ocean Look-Up Table (LUT) search; and
  • Fixed an error where very high Aerosol Optical Thickness (AOT) values greater than 3.5 were incorrectly reported as 0.02.


In this release, monthly climatology products are added at both 0.5° and 1.0° resolutions (see sample plot in Figure 1).  In addition, two new metadata attributes are added: digital object identifiers (DOI) are assigned to all products, and spatial completeness attributes are added to all Level 3 products.

Products are accessible through a number of data services, such as Mirador (GES DISC's Google-like data search engine), OPeNDAP, FTP, and ECHO/Reverb (the NASA EOSDIS centralized data search system). The Level 3 daily data and Level 3 monthly data are available in NASA Giovanni (online visualization system).  New analysis features have been added to the monthly Giovanni portal to analyze monthly climatology and anomalies.


More information and data file specification for the SeaWiFS Deep Blue Version 4 aerosol data set are available in the product README.

Data services and documentation can be found at the MEaSUREs/SWDB online portal.

Hsu, N. C. M.-Jeong, C. Bettenhausen, A. M. Sayer, R. Hansell, C. S. Seftor, J. Huang, and S.-C. Tsay (2013) Enhanced Deep Blue Aerosol Retrieval Algorithm: the 2nd Generation, J. Geophys. Res, doi: 10.1002/jgrd.50712 (accepted).


Sayer, A. M., N. C. Hsu, C. Bettenhausen, Z. Ahmad, B. N. Holben, A. Smirnov, G. E. Thomas, and J. Zhang (2012), SeaWiFS Ocean Aerosol Retrieval (SOAR): Algorithm, validation, and comparison with other data sets, J. Geophys. Res., 117, D03206, doi:10.1029/2011JD016599.


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Last updated: Aug 15, 2013 12:01 PM ET