Skip Navigation Links 
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
Environmental Modeling Center


NCEP SST Analysis

Because there are a number of different uses for sea surface temperature analysis, a number of different analyses have developed in NCEP. The two families are the RTG -- Real Time Global, and the OI -- Optimal Interpolation. The RTG analyses are aimed at weather prediction and modeling, particularly at high resolution and short range. The RTG analyses employ a 2DVAR analysis technique. The OI analyses are lower resolution and aimed more at long range weather and climate. Both have a history. We encourage users of the older analyses to examine the newer and let us know if the newer one fits your usage better.
NameSpace ResolutionTime ResolutionTechnique
Weekly OI 1 degree 7daysOI
Daily OI 1 degree ~7 daysOI
QDOI 0.25 degree, 15 arcminutes 1 dayOI
RTG Low Res 0.5 degree1 day2DVAR
RTG High Res 1/12th degree, 5 arcminutes 1 day2DVAR

In describing sea 'surface' temperature, there are actually several surface levels that data initially arrive on. For all 5 of our SST analyses, we reference a 'bulk' temperature -- a temperature representative of the upper layer of the ocean. This is approximately the temperature seen by buoys and some ships. Other ships observe lower in the water column. Infrared instruments, such as AVHRR and VIIRS observe most directly the 'skin' temperature, the upper 10 microns of the water. Microwave instruments, such as AMSR-E and WindSat, observe the upper couple of centimeters. -- General questions

NOAA/ National Weather Service
National Centers for Environmental Prediction
Environmental Modeling Center
5830 Unversity Research Court
College Park, Maryland 20740
Page Author: EMC Webmaster
Privacy Policy
About Us
Career Opportunities
Page last modified: Tuesday, 28-Aug-2018 12:55:17 UTC