13. Temperature in the Ocean

1. Introduction
2.  Salt in Seawater?
3. Ions of Salt
4. Source of the Salt?
5. Salinity Variability
6.Salinity & Precipitation
7. Salinity Summary
8. Calculating Salinity
9. Ocean Temperature
10. Solar Radiation
11. Properties
12. Light Penetration
13. Temperature
14. Thermocline
15. Density
16. Layering

Most all of the sun's energy (solar radiation) is absorbed at the surface, and has little effect in changing the temperature of the ocean below a few hundred meters.

Compounding the lack of light penetration into the sea is the fact that a tremendous amount of heat (energy) is required to alter the temperature of a large body of water like the ocean, because of the high heat capacity of water, which is the amount of energy required to raise 1 cm³ of water at atmospheric pressure by 1^oC.

Used with Permission of Matthias Tomczak ©Copyright 1997

We can see the variation of ocean temperature with water depth in the ocean in the graph above. The irregular gray line at the bottom of the graph is the sea floor and the horizontal line at the top is the sea surface.

Scales for water depth are shown on left, and color codes for sea water temperature are listed on right.

Is it now apparent why most of the ocean is cold?

Send to Don Reed
Department of Geology
San Jose State University

#7 Why is the vast majority of the ocean dark and cold?

a) Most of the solar radiation is absorbed at the surface.
b) Water has a high heat capacity.
c) The vast majority of the ocean is deep, consisting of basins between 4000 and 5500 meters in depth.
d) All of the above.
e) Both a and c.