Problem Set 7
Ocean 210, Autumn 2008
Due at the beginning of class on Friday, November 14, 2008
1. Rotation and the Coriolis force on a spherical Earth
a. Is the Coriolis force a real force? If not, what kind of force is it?
b. Why is there a Coriolis force and why do we study it?
c. Which way does the Earth rotate?
d. What is the Earth’s rotation rate in s-1?
e. At what latitude is the Coriolis force at a minimum?
f. At what latitude is it at a maximum?
g. Why does the Coriolis force change with latitude?
h. Does the Coriolis force change with longitude? Why or why not?
2. Rotation and the Coriolis force on non-spherical Planets
Now, imagine you are on each one of the crazy planets described below. These planets are
rotating too, just like the Earth.
• Planet One is a cylinder rotating at the same rate and in the same direction as the Earth,
and with a radius the same as the Earth.
• Planet Two is a cone. The radius of its equator is the same as the Earth’s radius and the
direction and rate of rotation are the same as on Earth.
• Planet Three is shaped just like the Earth, the rotation rate magnitude is the same but
this crazy planet is rotating in the opposite direction.
For EACH planet, answer these 4 questions.
i. Which way will the local apparent force due to rotation, call it Craziolis, deflect the
winds in the Northern half of the crazy planets?
ii. Where will Craziolis be at a maximum?
iii. At a minimum?
iv. Will Crazilois change as we move from the equator to mid-latitudes? Will it change
faster, slower, or at the same rate?
3. Wind-driven ocean currents
a. Which is your favorite wind-driven current and why?
b. Find out and describe which winds drive your current and how. Include the Coriolis
force and the pressure differences in your discussion (if relevant).
Good luck! Remember to show your work and include the plots! If you have a question or a
comment, please come to office hours (Wed 11:00-12:00 and Thu 1:00-2:30) or email me at: