Sea surface temperature, much like the atmosphere’s temperature,
is constantly changing. Water warms up and cools down at a slower
rate than air, so diurnal variations (heating during the day and cooling
during the night) seen in the atmosphere are hard to observe in the
ocean. The seasons, however, can be seen as the warmest water near the
equator expands toward the United States during the summer months and
withdraws again during the winter months. The interaction between the ocean and the atmosphere is one that scientists are constantly researching, and the temperature of the sea surface is a key factor in those interactions. Sea surface temperature anomaly is the difference between the current temperature and the long-term temperature average. Negative temperature differences indicate that the ocean is cooler than average, while positive temperature difference indicate that the ocean is warmer than average. Tracking sea surface anomalies helps scientists quickly identify areas of warming and cooling, which can effect coral reef ecosystems, hurricane development, and the development of El Nino and La Nina.
The real-time sea surface temperature dataset is provided by the NOAA Visualization Lab using data from NOAA’s Coral Reef Watch, meaning it is the same data source as other real-time ocean temperature products, such as SST, Coral Degree Heating Weeks and Coral HotSpots. The data combines measurements from all current geostationary and polar-orbiting satellites, including U.S. satellites and those of international partners such as Japan and Europe. Those measurements are then subtracted from the long-term mean SST for that day to create the anomaly. Since the data is at 5 km/pixel resolution, not only can you see large-scale patters such as El Nino-La Nina, but also many smaller features, such as hurricane wakes.
The entire archive of this imagery, starting in 1981, is available from NOAA View or FTP for download to your SOS computer.