Provider information for the Reynolds SST datasets.
Weekly Means
Information for the use of the NMC SST analyzed fields
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UPDATE INFORMATION (18 May 1994):
The OI fields have been extended back in time from the beginning of
1985 to the first week of November 1981. To account for spin up, the
first week of 1985 has been revised. All other weeks following the
first week of 1985 have not been changed. The OI analysis now covers
the period from November 1981 to present.
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The optimum interpolation (OI) sea surface temperature (SST) analysis
is produced weekly on a one-degree grid. The analysis uses in situ and
satellite SST's plus SST's 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). Because this document has not yet been published, a preprint
of the document is available by request.
The bias correction improves the large scale accuracy of the OI.
Examples of the effect of recent corrections is given by Reynolds
(1993). The bias correction does add a small amount of noise in time.
Most of the noise can be eliminated by using a 1/4-1/2-1/4 binomial
filter in time. We STRONGLY recommend that this filter be applied to
the data fields before they are used. An improved method of correcting
the biases is being developed.
For the more recent period, 1990-present, the in situ data were
obtained from radio messages carried on the Global Telecommunication
System. The satellite observations were obtained from operational data
produced by the National Environmental Satellite, Data and Information
Service (NESDIS). For this period the weeks were defined to be
centered on Wednesday. This was done to agree with the definition used
for ocean modeling.
In the analysis (see Reynolds and Smith, 1994) SSTs were generated in
ice covered ocean regions. After the analysis was completed, any
gridded SST values less than -1.8C were set to -1.8C. The analyses
were archived to only the nearest 0.01C. Because of round off as
analyses where moved between different computers, this minimum value may
change by up to +/- 0.02C.
During the period 1981-1989, the in situ data were obtained from the
Comprehensive Ocean Atmosphere Data Set (COADS) for the 1980s. These
data (see Slutz, et al., 1985, and Woodruff, et al., 1993) consist of
logbook and radio reports. The satellite data were obtained from
analyses of NESDIS data produced at the University of Miami's Rosentiel
School of Marine and Atmospheric Sciences. These satellite analyses
were produced for weeks centered on Sunday. Thus the OI weekly
analyses for 1981-1989 also were centered on Sunday. We hope that this
change in the definition of the week will not cause any problems.
The OI analysis is done over all ocean areas. There is no analysis
over land. The land values are filled by a Cressman interpolation to
produce a complete grid for possible interpolation. The ocean and land
areas are defined by a land sea mask.
REFERENCES
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 using optimum interpolation. J. Climate, 7,
929-948.
Slutz, R. J., S. J. Lubker, J. D. Hiscox, S. D. Woodruff, R. L.
Jenne, D. H. Joseph, P. M. Steuer, J. D. Elms, 1985:
Comprehensive Ocean-Atmosphere Data Set: Release 1. NOAA
Environmental Research Laboratory, Boulder, CO, 268 pp.
Woodruff, S.D., S. J. Lubker, K. Wolter, S.J. Worley, and J.D. Elms,
1993: Comprehensive Ocean-Atmosphere Data Set (COADS) Release 1a:
1980-1992. Earth System Monitor, Vol. 4, No. 1, September 1993,
NOAA.
Richard W. Reynolds (INTERNET: Richard.W.Reynolds@.noaa.gov)
Diane C. Stokes (INTERNET: Diane.Stokes@noaa.gov)
Climate Modeling Branch W/NP24
NCEP/NWS/NOAA
5200 Auth Road, Room 807
Camp Springs, MD 20746, USA
PHONE: (301) 763-8000 Ext 7580
FAX: (301) 763-8125
UPDATED: 18 May 1994
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Information for the use of the monthly NMC SST analyzed fields
The monthly optimum interpolation (OI) fields are derived by a linear
interpolation of the weekly OI fields to daily fields then averaging
the daily values over a month. The monthly fields are in the same
format and spatial resolution as the weekly fields.
The OI sea surface temperature (SST) analysis is produced weekly on a
one-degree grid. The analysis uses in situ and satellite SST's plus
SST's 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. Examples of the effect of
recent corrections is given by Reynolds (1993).
For the more recent period, 1990-present, the in situ data were
obtained from radio messages carried on the Global Telecommunication
System. The satellite observations were obtained from operational data
produced by the National Environmental Satellite, Data and Information
Service (NESDIS).
During the period 1981-1989, the in situ data were obtained from the
Comprehensive Ocean Atmosphere Data Set (COADS) for the 1980s. These
data (see Slutz, et al., 1985, and Woodruff, et al., 1993) consist of
logbook and radio reports. The satellite data were obtained from
analyses of NESDIS data produced at the University of Miami's Rosentiel
School of Marine and Atmospheric Sciences.
The OI analysis is done over all ocean areas. There is no analysis
over land. The land values are filled by a Cressman interpolation to
produce a complete grid for possible interpolation. The ocean and land
areas are defined by a land sea mask. This data set is an ascii file,
ls.dat, which is included in the same directory. The spatial grid is
defined identically to the grid for the SST arrays.
REFERENCES
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 using optimum interpolation. J. Climate, 7,
929-948.
Slutz, R. J., S. J. Lubker, J. D. Hiscox, S. D. Woodruff, R. L.
Jenne, D. H. Joseph, P. M. Steuer, J. D. Elms, 1985:
Comprehensive Ocean-Atmosphere Data Set: Release 1. NOAA
Environmental Research Laboratory, Boulder, CO, 268 pp.
Woodruff, S.D., S. J. Lubker, K. Wolter, S.J. Worley, and J.D. Elms,
1993: Comprehensive Ocean-Atmosphere Data Set (COADS) Release 1a:
1980-1992. Earth System Monitor, Vol. 4, No. 1, September 1993,
NOAA.
Richard W. Reynolds (INTERNET: Richard.W.Reynolds@noaa.gov)
Diane C. Stokes (INTERNET: Diane.Stokes@noaa.gov)
Coupled Model Project W/NMCx3
National Meteorological Center
World Weather Building, Room 807
5200 Auth Road
Camp Springs, MD 20746 USA
PHONE: (301) 763-8396
FAX: (301) 763-8125
UPDATED: 13 October 1994
