ATM OCN (Meteorology) 100

Answers for Homework 4

Summer 1999

Date Due: Thursday,  29 July 1999

The total maximum points were  50.  Point distribution for each question is noted below. 

PLANETARY ATMOSPHERIC CIRCULATION

[20 pts.]

 

A paragraph (with reasonably good grammar) should have included the fact that leaving New York, one is in the prevailing westerlies with some possible storms. Nearing the Florida coast, one would have reached the horse latitudes, with fair skies and weak winds, under the subtropical high pressure in the western Atlantic. Farther south, the northeast trades can be found with a persistent northeast wind and some cumuliform clouds. Near the equator, the doldrums also known as the Intertropical Convergence Zone, would have been reached, with hot, humid and cloudy conditions, with abundant rainshowers or thunderstorms. Sailing into the Southern Hemisphere, the southeast trades would be encountered first, then the subtropical highs of the South Atlantic (near southern Brazil and northern Argentina) then as one approaches Cape Horn, the prevailing westerlies would have dominated. The passage around the Cape would have probably been stormy in with migratory cyclones moving eastward across the Southern Oceans.

 

a. What is the approximate mean value of the sea-level pressure along the equator in January? and in July? Do you detect any significant seasonal change in intensity or location? If you do, please describe.
What is its average pressure in January? [1 pt.]

and in July? [1 pt.]

Do you detect any seasonal change in intensity? [1 pt.]

b. Locate the high pressure feature situated over the North Pacific Ocean near Hawaii.
What is its average central pressure in January? [1 pt.]

and in July? [1 pt.]

How has its position changed between January and July? [2 pts.]

c. Inspect the corresponding subtropical high pressure cells in the other ocean basins. What general statement can be made concerning the seasonal variation in the location and intensity of these features? [4 pts.]

d. Locate the low pressure feature located over the North Atlantic Ocean near Iceland.
What is its average central pressure in January? [1 pt.]

and in July? [1 pt.]

How has its position changed between January and July? [2 pts.]

e. Use the major pressure features over the North American and the Eurasian continents to make a statement as to the seasonal (winter versus summer) variations in the air pressure over the continents. [4 pts.]

 

During winter, the continents are dominated by large high pressure cells, with relatively lower pressure over the oceans, while in summer the continents have lower pressure than over the oceans.

 

URL Address: aos100/homework/99hmk04a.htm