Oceanography 204
Winter 1998
Due: February 17
Homework #4
Sea Breeze
Objectives:
Understanding of:
how spatial variation in heating affects air movement.
how air movement affects vapor content of air.
how heat capacity differences affect atmospheric circulation.
Questions
It is Spring Break and you decide to go camping with your Ocean 204 classmates on the Washington coast. Fortunately, you are blessed with beautiful sunny weather. During the day, you notice a nice cooling breeze coming off the ocean. However, as night falls, you notice that the wind changes direction and blows toward the ocean. Using what you know about heat capacity, explain this diurnal wind pattern.
Atmospheric pressure is defined as the pressure of the atmosphere pushing on the earth. Given your answer to question 1, where are regions of low pressure? Where are regions of high pressure? Explain.
Monsoon
Questions
The monsoon in India is a seasonally varying phenomenon. During the summer, the winds blow from the ocean toward land bringing wet air to the Indian subcontinent (the summer monsoon). During the winter, the winds blow from the land toward the ocean. This air movement results in cool, dry weather over the land (the winter monsoon). Using what we know about heat capacity, explain why the winds blow one direction during summer and another direction during winter.
Atmospheric pressure is defined as the pressure of the atmosphere pushing on the earth. Given your answer to question 1, where are regions of low pressure? Where are regions of high pressure? Explain.
Atmospheric Circulation (in the absence of rotation)
Objectives:
Understanding of:
how latitudinal variation in heating affects air movement.
how air movement affects vapor content of air.
Questions
Imagine a water covered earth with no continents and no rotation but heated by the sun like the real earth. Where would air tend to rise? Where would air tend to sink? Why?
Atmospheric pressure is defined as the pressure of the atmosphere pushing on the earth. Given your answer to question 1, where are regions of low pressure? Where are regions of high pressure? Explain.
Summarize your answers to questions 1 and 2 by drawing a picture of the vertical and horizontal movements of air on this hypothetical planet.
Due to pressure effects, air cools as it rises. Warm air can hold more water vapor than cold air. Given this information, discuss the vapor content of the air as it moves on the hypothetical planet. Where is the vapor content high? Where is it low? Where does it rain?
Summary
Questions
Compare and contrast a sea breeze with a monsoon. What causes these effects? What are the time and space scales for these effects?
Surface winds tend to blow from a region of _________________ atmospheric pressure to a region of _________________ atmospheric pressure.
Why are regions that are noted for their low atmospheric pressure famous for their excess precipitation?
Because continents rise high above the sea surface, they affect winds and precipitation. Winds sweep across the ocean, reach the land, and are forced to rise to continue moving across the land. Describe how this affects the vapor content of the air. Given wind flowing over a mountain range, which side of the mountains would tend to have more rain? Why?