Several polar and geostationary satellites continuously take measurements of sea surface temperature. These sea surface temperature [SST] data are then combined, blended, on a daily basis to produce global maps of sea surface temperature such as the one shown above. Colors from blue to red identify cold, temperate and warm surface waters. These SST maps also show currents and other ongoing ocean processes, which reflect a dynamic heat distribution system.
SST maps are useful for meteorologists that use them to help in weather predictions, and also to navigators to help chart currents and researchers. These SST maps are critical, together with atmospheric data, in tracking the process of cyclogenesis [tropical cyclone formation] throughout various ocean basins worldwide.
In the map above it is easy to see how much warmer surface waters are at the equator and to the south of it than in the northern hemisphere, reflecting the ongoing summer season in the southern hemisphere. As the Earth’s axis continues to tilt northward we will see SST maps charting a shift of warm ocean water to the northern hemisphere as the seasons reverse. This maps also shows an area of temperate water along the coastline of Peru, which identify the remnants of a La Nina event that developed in 2010 and affected weather patterns over northern South America, Central America and the Caribbean and also in Mexico and the USA.
For those interested in more information and ocean surface water temperature date I suggest you visit the NOAA/NESDIS/STAR Blended Sea Surface Temperature site at http://www.star.nesdis.noaa.gov/sod/mecb/blended_validation/index.php