EXERCISE 18 



IN WHAT DIRECTION DOES THE AIR MOVE AROUND THE CENTER OF A 



LOW-PRESSURE AREA? 



Materials. Weather maps used in preceding exercise. 



Directions. In the part of the map used in the preceding exercise, consider only those arrows 

 included in (a), and determine : (1) how many of these arrows which indicate that the wind blows 

 inward are there which cross the isobar perpendicularly ; (2) how many arrows turn to their right 

 of a line perpendicular to the isobar ; (3) how many arrows turn to their left. What percentage 

 of the arrows turn to their right ? What does this result show about the general direction of the 

 wind in a " low " ? Make a diagram about 2 inches in diameter, showing the wind direction about 

 a " low." Is this direction clockwise or counterclockwise ? 



Additional problem. If a "low" were to pass eastward across the country along a path lying north of 

 you, what changes in wind direction would be experienced in your locality ? What changes would there 

 be if it passed south of you ? 



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