1. What are the "astronomical" boundaries of the tropics?
The Tropic of Cancer and Tropic of Capricorn
2. How can isotherms be used to delimit the tropics? What are isotherms?
Isotherms are lines on a map that connect points of equal temperature. Bates points out that the Tropics' astronomical boundaries separate locations with very similar climates. He uses the 70 degree average annual temperature isotherm to show how climates north and south of the Tropic of Cancer are similar.
3. Why does Bates claim that "climate types within the tropics depend primarily on rainfall"?
As you saw in your climagraphs and in Bates' chapter, tropical climates do not have a distinct temperature season. The annual temperature range is low (1-5 degrees). Differences in temperatures in tropical climates result from differences in elevation (Compare the temperature lines that you graphed for La Ceiba, Tegucigalpa and Huehuetenango) Differences in tropical climates result from differences in precipitation. Some tropical climates have rain all 12 months (La Ceiba). Some climates have distinct wet and dry seasons (Tegucigalpa and Huehuetenango).
4. Study the map on p. 87 and know the difference between the astronomical and climatic lines that are shown.
5. Just skim p. 88-90.
6. What is the difference between weather and climate?
Weather = short-term conditions of temperature, precipitation, wind and atmospheric pressure;
Climate = long-term average of temperature, precipitation, wind and atmospheric pressure
7. According to Bates, why is climate and not weather "a property of the Tropics"?
Bates makes this claim because of the monotony of Tropical climates. I agree with him for the most part. However, he does neglect to mention short-term phenomena like hurricanes.
8. What are the "two sorts of factors" that influence tropical climates?
1. Astronomical (Earth's rotation on its axis, Earth's orbit around the sun, and the tilt in Earth's polar axis)
9. Read and re-read p. 91-the top of p. 93. You must learn that basic information. Be certain that you learn the names and locations of the pressure areas and wind belts.
10. What pressure areas and wind belts does Bates describe? Where are they?
Bates includes a diagram on page 92 that shows pressure areas and wind belts. For the regions that we are studying, the most important of these are: Equatorial Doldrums (also known as the Equatorial Low Pressure Belt), the Horse Latitudes (also known as the Sub-Tropical High Pressure Belt), and the Northeast Trade Wind belt. The Equatorial Doldrums is a low-pressure belt centered on the equator caused by the intense heating of the region and the rising of heated air. The Horse Latitudes are high-pressure belts in both hemispheres caused by cooled air descending to EarthÕs surface. The Northeast Trade Winds, which blow across the Caribbean and Central America, diverge out of the Horse Latitudes and flow toward the Equator.
11. What is the "heat equator"? What does do throughout the year? In which direction is it traveling currently?
The "heat equator" is that latitude at which the sun's rays strike Earth's surface at a 90-degree angle and cause the most rapid and intense heating on Earth's surface. The "heat equator" slowly migrates from one tropic to the other tropic during 6 months, and back again during the following 6 months. When the heat equator is at the Tropic of Cancer, June 21, the northern hemisphere begins its summer. Currently the heat equator is between the equator and the Tropic of Capricorn and is moving northward. It will be at the equator on March 22, the equinox.
12. Learn Bates' 4 basic climate types and associated vegetation groups.
Humid = rain forest Subhumid =grassland Semiarid = steppe arid = desert
13. Look at the Climates map. What kinds of climates are found in our region of study?
Humid and subhumid
14. How did Bates' living situation in Colombia demonstrate for him the topographical factor and its influence on climate?
The topographical factor refers to Earth's lumpy surface. It is covered by mountains, plateaus, valleys...In Colombia Bates lived at the base of the Andes. As he ascended the Andes he noted that climates and vegetation changed dramatically as his elevation increased.
15. So, what does it mean when we say "tropical climates"?
Not much. Tropical climates are varied, but one characteristic that they all share is a low annual temperature range.