Data & Products
Missions & Sensors
Sea Surface Temperature
The "Sea Surface Temperature derived from NOAA-AVHRR data (SST_AVHRR)" are three
grid maps for the Western Atlantic (2500 lines/ 3900 samples), Mediterranen
Sea (2048 lines / 4096 samples) and the Madeira area (2200 lines / 1350 samples)
in Mercator projection with the earth radius of 6378.137 km (no geoid, no ellipsoid!).
All maps have a spatial resolution of about 1.1 km at the center of the satellite
map. All MCSST data are transformed to the fixed grid projection by resampling
and interpolation the dataset on a pixel by pixel basis. The simplest nearest
neighbor algorithm is used. Within 24 hours of acquiring data from the satellite,
SSTs are calculated. In general, the products utilise data from all six of the
passes that the satellite makes over Europe in each 24 hour period. The SST
maps are composed according the maximum temperature value given at every pixel's
position to minimize cloud coverage. Weekly and monthly products are derived
from the daily maximum images using the average at every pixel's position.
The operational production chain was launched in March 1993 covering the entire Mediterranean Sea and the Black Sea. Since then, daily, weekly, and monthly data sets have been available. The product is intended for climate modelers, oceanographers, and all geo science-related disciplines dealing with ocean surface parameters. In addition, SST maps covering the North Atlantic, the Baltic Sea, the North Sea and the Western Atlantic equivalent to the Mediterranean MCSST maps are available since August 1994. The most important aspects of the MCSST maps are a) correct image registration and b) reasonable cloud screening to ensure that only cloud free pixels are taken for the later processing of composition.
The applied formula for deriving SST is based on the brightness temperatures of AVHRR channels 4 and 5 (T4 T5) and is described by McCLAIN et al. (1985). This technique is known as the "Split Window Technique" and corrects atmospheric attenuation mainly caused by absorption of water vapor in the atmosphere, which normally leads to a significant drop in derived brightness temperatures, depending on the region down to 8 degrees Celsius.
Dech, S., Tungalagsaikhan, P., Preusser, C., & Meisner, R., 1998. Operational value-adding to AVHRR data over Europe: methods, results, and prospects. Aerospace Science and Technology, 5, 335-346.
Sea surface temperature (SST) is an important factor controlling most physical, chemical, and biological processes of the oceans.
Contact: Dr. Kurt P. Günther