GAC and HRPT AVHRR Reprocessing to GHRSST

The objective of this three year effort is to develop a 28 year (1982-2010) global SST data set at full GAC resolution – 4km at nadir – and regional SST data sets at full HPRT resolution – 1km at nadir. All of these data sets (shown graphically in Figure 1) will be developed from the AVHRR data stream and will be made accessible to the community as part of the GHRSST program. The regional data sets will cover eastern and western North Pacific waters and western North Atlantic waters. The western North Atlantic regional data set, waters off the east coast of the US, will cover 1982-2001. The eastern North Pacific data set will extend from 1992 through 2000 and that for the western North Pacific from 1985 through 1999. The tasks required to accomplish this fall into four groups.

  • Generation of error look-up tables (hypercubes) for the AVHRR time series 1982-2010. The GHRSST protocol requires pixel error estimates of retrieved SST values. UMiami has developed the 'hypercube' approach for MODIS SST fields to accomplish this. The same approach will be used for the AVHRR data. Two subtasks are necessary to incorporate this into the AVHRR SST project:
    - Generate hypercubes to allow error estimates for the AVHRR-derived fields, and
    - Modify the SeaDAS software to make use of the AVHRR hypercubes.
  • Modify the ingestion and navigation portion of SeaDAS to allow ingestion and processing of the three HRPT AVHRR data streams in the URI archive. This task mirrors for the HRPT data, the effort currently underway at UMiami to incorporate the CLASS AVHRR GAC data into the SeaDAS processing system.
  • Process the three major HRPT data streams (western N. Atlantic and eastern and western N. Pacific) from L1b to L2Pcore and from there to L3Pcore. This task uses hypercubes (Task group 1) together with the ingest routines (Task 2) developed by UMiami to process the three data streams in the URI archive.
  • Process the GAC AVHRR global data set for 1982-2010 to L2Pcore & L3Pcore. (Blue line in Figure 1.)

As part of this effort, the PI will coordinate this activity with that of Mike Chin of JPL who is producing a level 4 SST product.

<b>Figure 1</b>. Processing of data streams. Red corresponds to HRPT data streams and processing is to be done by URI. Blue is for the global GAC data stream and processing is to be done by NODC (no cost to NASA).
P. Cornillon - PI, U. Rhode Island
Bob Evans - Co-PI, U. Miami
Ken Casey - Co-PI, NODC

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Page Last Updated: May 2, 2019 at 12:07 PM EDT