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.
|Name||Space Resolution||Time Resolution||Technique|
|Weekly OI|| 1 degree|| 7days||OI|
|Daily OI|| 1 degree|| ~7 days||OI|
|QDOI|| 0.25 degree, 15 arcminutes|| 1 day||OI|
|RTG Low Res|| 0.5 degree||1 day||2DVAR|
|RTG High Res|| 1/12th degree, 5 arcminutes|| 1 day||2DVAR|
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.
Robert.Grumbine@noaa.gov -- General questions