Lab # _____ - Sea Surface Temperature and Salinity
Background: Sea surface temperature depends on latitude and surface ocean currents. Sea
surface temperature affects salinity of ocean water. Monitoring of sea surface
temperature and salinity is important because these ocean properties directly influence the
lives of marine organisms. Today you will use the DataStreme Ocean Web page to collect
sea surface temperature and salinity data.
Objective:
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To use sea surface temperature and salinity data to explain two sections of the ESRT:
Surface Ocean Currents and Planetary Wind and Moisture Belts in the Troposphere.
Materials: Internet access, ESRT, red, blue and yellow color pencils
Time: 1 Period
PART A – SEA SURFACE TEMPERATURES
Procedure:
1. Go to http://www.ametsoc.org/amsedu/DS-Ocean/home.html
2. Scroll down to the “Physical & Chemical” Section. Click on Sea Surface Temperatures.
Print out the map in landscape view.
3. In large lettering write “Sea Surface Temperatures” at the top of the printed page.
4. Click on Gulf Stream Current to view the exact location of the Gulf Stream Current.
5. Open the ESRT to the “World Surface Ocean Currents” map. Print the map and locate
the Gulf Stream on the map.
a. Where does the Gulf Stream Current originate? How does this relate to its
characteristics as highlighted on the Gulf Stream Current map?
6. Compare the “World Surface Ocean Currents” map with the Sea Surface
Temperatures map.
a. What patterns do you notice? What might be the underlying physical
properties causing these patterns?
b. What discrepancies do you note? What might be the underlying physical
properties causing these discrepancies?
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7. To make life easier, on the ESRT, color in all warm currents RED and all cold currents
BLUE.
a. If the Gulf Stream did not exist, then how would the climate of Western
Europe be different?
b. If the California current did not exist, then how would the climate of the
United States’ west coast be different?
c. Based on the ESRT, explain why there is a difference between the sea surface
temperatures of the east and west coast of the continental United States.
d. What differences in the physical properties of warm and cold currents might
be important in understanding the movement of thermal energy around the
planet?
PART B - SALINTIY
Procedure:
1. Go back to http://www.ametsoc.org/amsedu/DS-Ocean/home.html
2. e. In the “Earth System” Section, click on NOAA World Ocean Atlas 2005. Click on
“Salinity” Choose “Climatology” for the figure type, Choose “Annual” for Time Period,
Choose “Surface” for Depth
3. Print out in landscape view.
4. In large lettering write “Salinity” at the top of the printed page.
Analysis of Data:
5. Where is the highest surface salinity found?
6. Where is the lowest surface salinity found?
7. Now click on the red arrow labeled “down 1 depth level” and observe the changes in
the graph as you descend.
a. How does the salinity change as a function of depth? Sketch a graph to
illustrate your observations
b. What are the underlying physical properties responsible for these changes?
c.
8. Now do the same thing for temperature. Observe the surface temperature at varying
depths (surface, 100, 500, 1000, 1500, 2000, 2500) and sketch a graph to illustrate
your observations.
a. What physical properties are responsible for these changes?
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b. How do these data compare with the salinity results? Fill in the following table
to summarize what you found:
DEPTH
SURFACE
DEEP OCEAN
RELATIVE TEMPERATURE
RELATIVE SALINITY
9. Open the ESRT to the “Planetary Wind and Moisture Belts in the Troposphere”.
a. What latitudes have a wet moisture belt? In the ESRST, color the wet
moisture belts BLUE.
b. What latitudes have a dry moisture belt? In the ESRT, color the dry moisture
belts YELLOW.
c. Given the physical properties of the ocean surfaces in these areas, explain
these patterns
10. Tie it together:
a. A cup holds water with salt dissolved in it. If more water is added to the cup, how
will the concentration of salt be affected? The density of the solution? (show
your work!)
b. A cup holds water with salt dissolved in it. If water is removed from the cup, will
the concentration of the salt solution be affected? The density? (show your
work!)
c. Low pressure persists at equatorial regions, which results in high precipitation.
Would higher precipitation result in lower or higher salinity? Why?
d. At 60N and 60S precipitation occurs more than evaporation. Would high or low
salinity be expected at these latitudes? Why?
e. Due to the low temperatures, polar regions experience less evaporation than
precipitation. Explain how this likely affects the salinity of seawater in these
regions.
f. At 30N and 30S, compare the relative amount of evaporation and precipitation.
g. At these locations, would a higher or lower salinity be expected? Why?
h. How might the melting of polar glacial regions affect the salinity of the water in
these regions? How would this affect the movement of ocean currents?
11. Lets organize the data from the ESRT and website into a data table.
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Latitude
Precipitation or
Evaporation Greater
Salinity
(High or Low)
Agreement Between the
ESRT and Website
(Yes or No)
0
30
60
90
Characteristics
West Coast US
(Higher or Lower)
East Coast US
(Higher or Lower)
Sea Temperature
Evaporation
Salinity
Finally….
HOW MIGHT TEMPERATURE AND SALINITY BE
IMPORTANT IN THE TRANSPORT OF THERMAL ENERGY
AROUND THE PLANET’S OCEANS? WHAT IMPLICATIONS
DOES THIS HAVE FOR CLIMATE?
This laboratory investigation was modified from
DataStreme Ocean Benchmark Investigation 3A
Seawater Temperature, Salinity and Density
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