Introduction to Physical Oceanography
Homework Set 6
Due 15 October 2008

Late homework will cost 15 points per week or part of a week it is late.

1. Upwelling: This image of sea-surface temperature in the Indian Ocean on 1 October 2005 shows cold water offshore of Somalia indicating strong upwelling along the coast of Somalia. Upwelling of cold water is common in this region in late summer through October. Yet, this is off the east coast of Africa, and upwelling typically occurs on west coasts of continents.
   
   
   1. Why is upwelling common offshore of Somalia at this time?
      
      
2. Ekman Transports: What is the direction of the Ekman transport at any point relative to the eye of the hurricane? To answer the question:
   1. Sketch the circulation in the atmosphere near the eye of a hurricane.
   2. On the sketch, draw arrows showing Ekman transport in the ocean at several points around the eye of the hurricane.
   3. What vertical currents might result from this pattern of Ekman currents?
      
      
3. Geostrophic Currents: Why can't direct measurements of pressure made at different locations in the ocean be used to calculate pressure gradients and therefore the baroclinic (relative) geostrophic currents?
   
   
4. Geostrophic Currents: Briefly describe baroclinic and barotropic components of geostrophic flow.
   1. Which component is calculated by the geostrophic method applied to hydrographic observations made from ships?
      
      
5. Sverdrup Circulation: The Gulf Stream and Kuroshio both leave the coast near 40° N latitude. Why? Hint: It has to do with Sverdrup
   circulation and the idea that the streamlines of the Sverdrup circulation are closed at a western boundary by a western boundary current.
   

Revised on: 27 August, 2008