4 km AVHRR Pathfinder Project

***ANNOUNCEMENT 27 August 2016: NCEI releases AVHRR Pathfinder Version 5.3***

NCEI is pleased to release the AVHRR Pathfinder Version 5.3 (PFV53) sea surface temperature data set. See https://data.nodc.noaa.gov/cgi-bin/iso?id=gov.noaa.nodc:AVHRR_Pathfinder-NCEI-L3C-v5.3 for more information.

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***ANNOUNCEMENT October 2013: NODC releases AVHRR Pathfinder Version 5.2 for the year 2012***

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The AVHRR Pathfinder Version 5.2 (PFV52) data set was computed using an entirely modernized system, based on SeaDAS and incorporating several key changes over the older Pathfinder V5.0 and V5.1 datasets. PFV52 is viewed as a significant step forward in preparation for the future Version 6 (PFV6) data set (no release has yet been established for PFV6). Changes in PFV52 include the use of an entirely new land mask, a modified grid, and the inclusion of sea ice and wind speed ancillary data to support the use of the SST data. Importantly, the new PFV52 data are provided in netCDF-4 (classic model, with internal compression and chunking) and are nearly 100% compliant with the GHRSST Data Specification Version 2.0 (GDS2.0, http://data.nodc.noaa.gov/pathfinder/Version5.2/GDS_TechSpecs_v2.0.pdf) for L3C products. These data deviate from that standard only in that the sses_bias, sses_standard_deviation, and sst_dtime variables are empty. Data for 1981-2012 are available. All of the PFV52 data are available through NCEI's FTP, HTTP, OPeNDAP, and THREDDS access systems:

• HTTP: http://data.nodc.noaa.gov/pathfinder/Version5.2/
• FTP: ftp://ftp.nodc.noaa.gov/pub/data.nodc/pathfinder/Version5.2/
• OPeNDAP: http://data.nodc.noaa.gov/opendap/pathfinder/Version5.2/ (Hyrax server needs to be updated to most recent version before it can serve the Pathfinder V5.2 netCDF-4 data)
• THREDDS: http://data.nodc.noaa.gov/thredds/catalog/pathfinder/Version5.2/catalog.html THREDDS supports OPeNDAP, so you can use OPeNDAP through the THREDDS server using this link.
• Browse Images and KML: http://data.nodc.noaa.gov/pathfinder/Version5.2/browse_images

Pathfinder is a NOAA official Climate Data Record for Sea Surface Temperature: http://www.ncdc.noaa.gov/cdr/

In addition to embracing the National Research Council CDR definition (Climate Data Records from Environmental Satellites: Interim Report 2004) , NOAA operational CDRs are routinely assessed for quality and systematically generated. The first step in establishing an operational CDR includes public posting of the source code that generated the CDR dataset, the dataset itself, and supporting documentation through a six-phase Research-to-Operations process that is described in the Developers Guidelines.

Once posted to the NCDC webpage, the CDRs are grouped by Fundamental CDRs and Thematic (Atmospheric, Oceanic, and Terrestrial) CDRs. Fundamental CDRs are sensor data (e.g. calibrated radiances, brightness temperatures) that have been improved and quality controlled over time, together with the ancillary data used to calibrate them. Thematic CDRs are geophysical variables derived from the FCDRs, such as sea surface temperature and sea ice concentration, and they are specific to various disciplines. Thematic CDRs are often generated by blending satellite observations, in-situ data, and/or model output.

The following table lists known issues with the PFV52 data set:

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Acknowledgment & Citation:

If you use Pathfinder 4km data, please acknowledge the use of these data with the following statement: "These data were provided by GHRSST and the US National Oceanographic Data Center. This project was supported in part by a grant from the NOAA Climate Data Record (CDR) Program for satellites".

and cite the following publication:

Casey, K.S., T.B. Brandon, P. Cornillon, and R. Evans (2010). "The Past, Present and Future of the AVHRR Pathfinder SST Program", in Oceanography from Space: Revisited, eds. V. Barale, J.F.R. Gower, and L. Alberotanza, Springer. DOI: 10.1007/978-90-481-8681-5_16. (Click here for a PDF copy).

Sample text for a journal article:

In this study, we used AVHRR Pathfinder Version 5.2 (PFV5.2) data, obtained from the US National Oceanographic Data Center and GHRSST (http://pathfinder.nodc.noaa.gov). The PFV5.2 data are an updated version of the Pathfinder Version 5.0 and 5.1 collection described in Casey et al. (2010).