Exercise 10: Atmospheric and Oceanic Circulation

Atmospheric and Oceanic Circulation
1) View drifter and satellite data that illustrate how the ocean circulates.
2) Identify the basic layers of the equatorial ocean, based on vertical profiles of
ocean temperature measurements.
3) Learn how to find a scientific article in the SFSU library.
Go to the Earth Systems Laboratory and open the following WWW site:
http://geosci.sfsu.edu/courses/geol103/labs/labs.html. Open the Atmospheric and Oceanic
Circulation exercise. Exercise questions and space for answers are provided below.
PART I: Plotting ocean buoy data to show surface currents
1. (a) Plot the 1995 data from 3 buoys in the North Pacific (Table 1) on the Pacific
Ocean map provided. Label the numbers on the map as N and S latitudes and E and W
(b) Refer to the Map of Surface Currents.
What are the names of the surface currents that moved the buoys whose courses you
Buoy 12410:
Buoy 15022:
Buoy 22217:
(c) The currents plotted in (a) are all part of the North Pacific gyre, a clockwise-moving
current that redistributes heat in the North Pacific. What is the name of the current that
moves water past the coast of California?
Do you think it carries warm or cold water past the coast of California?
PART II continued: Other satellite imagery
4. (a) Describe the general pattern of sea surface temperatures in the ocean.
(b) Examine the zone of warm water along the equator. Why does this zone widen to
the west in each ocean; for example, in the Pacific Ocean? (Hint: look at the
Atmospheric Circulation diagram and the Surface Currents map.) Perturbations to this
pattern are involved with the El Niño climatic condition.
6. (a) What is the temperature range of the Gulf Stream current?
(b) What is the temperature range of the Labrador current?
(c) Describe what changes occur in the currents during the 6-day period between the
two images. For example, notice what happens with the ring of Gulf Stream water
enclosed in the colder water.
(d) Describe the boundaries of the Gulf Stream. For example, are they sharp or diffuse;
straight or meandering?
PART III: Vertical structure of the ocean
8. (a) On a paper copy of the graphs, mark the depths of the boundaries between the
surface zone, thermocline, and deep zone. Label the 3 zones.
(b) Which graph represents the vertical temperature profile of the Pacific Ocean
closest to South America (110W, 140W, or 180W)?
(c) What changes do you observe from east to west along the equator in the Pacific
(d) Briefly explain what causes these differences.