Ocean Circulation (UMAP)

This module looks first at how an ocean current is affected by the fact that it moves on a rotating sphere. It considers an ocean current that is motivated entirely by the Coriolis effect; such currents are called geostrophic. Since most of the deep ocean currents are largely geostrophic, the discussion will give some insight into how deep-ocean current charts might be constructed. Finally, the Corilois effect on surface currents driven by a steady wind is examined. The equations will show that, for example, the trade winds blowing toward the southwest in the Caribbean actually push the water 90 degrees to the right, in the northwest direction, forming part of the Gulf Stream current. An appendix on complex numbers is included, which briefly shows how they can be used to represent motion in the plane.

Table of Contents:

INTRODUCTION

THE CORIOLIS EFFECT

ROTATING FRAME VS. FIXED FRAME

GEOSTROPHIC CURRENT

WIND EFFECT IN COASTAL WATERS

WATER RESPONSE TO THE WIND

WATER TRANSPORT DIRECTION EQUATION

PATH OF A WIND-DRIVEN CURRENT

FURTHER DIRECTIONS

SOLUTIONS TO SELECTED EXERCISES

APPENDIX ON COMPLEX NUMBERS

REFERENCES

ABOUT THE AUTHOR