Image of the Month for August
Current Sea Surface Temperatures
What is “sea surface temperature” (SST)?
SST usually refers to the temperature of ocean water at a depth of one meter below the surface, not actually at the surface.
How is SST measured?
Temperature probes attached to floating buoys in the ocean are used to take some temperature readings, but most SST data is inferred (estimated) from satellite data.
How are maps of SST created?
The SST data is used to create a color-coded map. (Different researchers may choose slightly different color codes, but, in general, warmer temperatures are indicated by oranges and reds, while cooler temperatures are indicated by blues and purples.)
Exploring this Map:
Compare this map to a world globe. Notice how distorted the sizes of Antarctica and Greenland are on this map! To understand why, notice that on a globe all the longitude lines pass through the poles, but on this map they are vertical lines that make a square grid with the latitude lines.
This type of map distorts both the sizes and shapes of the continents, but this it the easiest type of map to use with satellite data, which records data by latitude and longitude.
Imagine drawing longitude and latitude lines on an inflated round balloon and then deflating it. To make it look like the map above, you would need to cut off the “poles”, cut the balloon along the longitude 180-degree line, and then stretch the top and bottom edges out.
Compare recent SST maps to the map above. What differences do you see?
Why measure sea surface temperatures?
- Sea surface temperatures must be 80 degrees Fahrenheit (F) or warmer for hurricanes to form and persist.
- Changes in sea surface temperatures in the Pacific can be used to predict El Nino events.
- Sea surface temperatures affect the growth of phytoplankton, tiny plant-like organisms that capture sun energy and form the base of ocean food webs.
Last updated on
August 7, 2007
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