Unformatted text preview: Exercise #5 1. On the following diagram (both part A and part B) in the Northern Hemisphere, the isobars are labeled in millibars and north is directed towards the top of the page. N In Part A, if the wind was driven solely by the pressure gradient force, it would flow Toward the South If the wind was driven by both the pressure gradient force and coriolis, it would flow Toward the West In Part B, if the wind was driven solely by the pressure gradient force, it would flow Inward If the wind was driven by both the pressure gradient force and coriolis, it would flow Counterclockwise On both parts of the above diagram, where would the windspeed be the fastest? Where the isobars are the closest. 2. In your own words, describe the coriolis force: Coriolis is the apparent deflection due to rotation of the earth. 5-6 3. Friction is related to wind speed and the surface roughness and is a third force that affects the flow of air. Is friction greater over land or over water surfaces? Why? Greater over land due to the fact that trees, buildings, etc are all obstructions to the wind. Is friction greater at low or high altitudes? Why? Low altitudes since there are few obstructions as you go higher above the Earth. 4. For each of the following, list the predominant direction of the wind (or indicate if wind speed is small or insignificant) and where each are found on the earth (approximate latitude). Wind Direction Location Doldrums Horse Latitudes Polar Easterlies Roaring 40's Southeast Trade Winds Westerlies
Light or insignificant Near the Equator Light or insignificant
East to West West to East Near 30°N latitude
Between 60° and 90° N & S latitude 30°S to 60°S latitude Between 0° and 30°S latitude Between 30° and 60° N & S latitude Southeast to Northwest
West to East 5. We will soon be discussing the Intertropical Convergence Zone (ITCZ). From our discussion of global winds, where do you suppose the ITCZ is located and why is it so named? Between the tropics, between the Northeast Trades and the Southeast Trades 6. Why does air pressure decrease with altitude? Air pressure is a measure of the weight of the atmosphere above us. Thus, as altitude increases, less air presses down and thus the air pressure decreases. 5-7 ...
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- Fall '08
- Geography, Equator, pressure gradient force, Millibars