Description and Recent Reanalysis
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Frequently Asked Questions
The optimum interpolation (OI) sea surface temperature (SST) analysis is produced weekly on a one-degree grid. The analysis uses in situ and satellite SSTs plus SSTs simulated by sea ice cover. Before the analysis is computed, the satellite data is adjusted for biases using the method of Reynolds (1988) and Reynolds and Marsico (1993). A description of the OI analysis can be found in Reynolds and Smith (1994). The bias correction improves the large scale accuracy of the OI.
In November 2001, the OI fields were recomputed for late 1981 onward.
The new version will be referred to as OI.v2.
The most significant change for the OI.v2 is the improved simulation of
SST obs from sea ice data following a technique developed at the UK Met
Office. This change has reduced biases in the OI SST at higher
latitudes. Also, the update and extension of COADS has provided us with
improved ship data coverage through 1997, reducing the residual
satellite biases in otherwise data sparse regions. For more
details, see Reynolds, et al (2002).
The weekly fields are available in binary files in:
Monthly fields are available in:
Documentation with sample source codes to read the data are available as README files in the above directories.The Data Support Section (DSS) of NCAR makes both available in ASCII at: http://rda.ucar.edu/datasets/ds277.0/
A climatology based on the OI.v2 Reanalysis fields was developed at the Climate Prediction Center using the method of Reynolds and Smith (1995) and Smith and Reynolds (1998). This climatology is described in:
and available in:
Reynolds, R.W., 1988: A real-time global sea surface temperature analysis. J. Climate, 1, 75-86.
Reynolds, R.W., 1993: Impact of Mount Pinatubo aerosols on satellite-derived sea surface temperatures. J. Climate, 6, 768-774.
Reynolds, R. W. and D. C. Marsico, 1993: An improved real-time global sea surface temperature analysis. J. Climate, 6, 114-119.
Reynolds, R. W. and T. M. Smith, 1994: Improved global sea surface temperature analyses. J. Climate, 7, 929-948.
Reynolds, R. W. and T. M. Smith, 1995: A high resolution global sea surface temperature climatology. J. Climate, 8, 1571-1583.
Smith, T. M. and R. W. Reynolds, 1998: A high resolution global sea surface temperature climatology for the 1961-90 base period. J. Climate, 11, 3320-3323.
R. W., N. A. Rayner, T. M. Smith, D. C. Stokes and W. Wang,
2002: An improved in situ and satellite SST
analysis for climate. J. Climate, 15, 1609-1625.
(Dick Reynolds is busy enjoying retirement)