Investigate the relationship between winds, surface currents, sea surface temperature and up welling and down welling.

• Understand how scientists report direction in compass points, azimuth bearings, and quadrant bearings.
• Investigate the relationship between winds, surface currents, sea surface temperature and up welling and

down welling.

• Determine if up welling or down welling was occuring along the Pacific Northwest coast in September of 2013.

Background

Seasonal up welling is a very important process not just to the Pacific Northwest but to many coastal regions in the world. During the summer in the Northern Hemisphere, upwelling is driven by winds blowing from the North to the South (Northerlies) that, combined with the Coriolis Effect, push surface water off-shore and out to sea.

Upwelling pulls deep ocean water up to the surface making the surface coastal ocean more salty, cold, and nutrient rich. The added nutrients in the sunny surface waters trigger fast phytoplankton growth and reproduction, which is the base of the food web and supports the important fisheries along the West Coast of the US.

Background Knowledge

To measure and report relative directions on Earth, scientists use compass points, azimuth bearings, and quadrant bearings. This measurement system measures horizontal directions, as if you were in the air looking down at a flat surface. Take a few minutes to review these resources on compass points, azimuth bearings, and quadrant bearings:

• Thinking in Circles (http://academic.brooklyn.cuny.edu/geology/leveson/core/linksa/comp.html).
• Section: Points of a Compass (http://gwydir.demon.co.uk/jo/units/angles.htm#compass)

The figure below summarizes these three systems by giving the location of the red star using each system.

Compass point: SE Azimuth Bearing: 140° Bearing: S40°E

(E4) Exercise #4 – Page 1 of 10

Once you understand the difference between the three systems (compass points, azimuth bearings, and quandrant

bearings), complete the exercise below.

On the drawing of a compass to the right, assume that “A” is zero degrees. List the compass point, azimuth beari