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6. Salinity and Precipitation

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

Used with Permission of Matthias Tomczak ©Copyright 1997

Here you see a plot of the difference in the amount of evaporation and precipitation along a line of longitude from the northern polar region (on left edge of graph) to the southern polar region (on right edge of graph) -- see scale at bottom of graph at left.

The location of these data is shown on the map below.

The curves in the graph above show the variation of several properties with latitude.

Remember that there are 2.54 centimeters in 1 inch.  

• precipitation in brown (centimeters per year) - top graph, scale on left,
• evaporation in blue (centimeters per year) - top graph, scale on left,
• ocean salinity in red (parts per mil), bottom graph, scale on right
• A fourth quantity has been calculated by determining the difference in the amount of evaporation and precipitation each year:

  E-P or evaporation minus precipitation in green --  bottom graph, scale on left.

Used with Permission of Matthias Tomczak ©Copyright 1997

• How does the curve of E-P compare to the curve of salinity?
  
  
• Given the relations shown in the graph above, what process controls the salinity of the surface waters of the ocean?

Send to Don Reed
Department of Geology
San Jose State University

#5 Based on this graph where would you expect to find regions of high salinity in the ocean?

a)In the polar regions
b)Near the equator
c)In the subtropical regions (centered at 30^oN and 30^oS)