Chapter 10 Low Latitude Climates OVERVIEW This chapter focuses on the climates that are found between the Tropic of Cancer and the Tropic of Capricorn. Low latitude climates: occupy the equatorial zone, much of the tropical zone, and some of the subtropical zone include climates that range from very wet to very dry are influenced by the intertropical convergence zone, tropical easterly wind systems, and the subtropical high pressure cells experience traveling low pressure systems such as the easterly wave and tropical cyclones The wet equatorial climate is characterized by: dominance of the intertropical convergence zone (ITC) mE and mT air masses uniform, very warm temperatures in all seasons ample precipitation, heaviest when the ITC is nearby Monsoon and trade wind coastal climates are characterized by: heavy rainfall with strong seasonal patterns a larger temperature range than the wet equatorial climate dominance of the ITC during the heavy rainfall period and the subtropical high pressure system during the dry season trade wind coast climates are a result of mT and mE air masses blowing onto coastal areas bringing large amounts of moisture the monsoon aspect of these climates is a result of the changing position of the ITC and reversing pressure gradients heavy rainfall is associated with the ITC and an airflow from ocean to land, while the dry season is associated with airflow off the Asian continent to the ocean The wet equatorial, monsoon, and trade wind coastal climates produce low latitude rainforest with dense vegetation, numerous streams, and a great diversity of plant and animal life. Products and resources of the rainforest include lumber, drugs, rubber, and foods such as cassava, yams, taro, bananas, plantain, and coconuts. The wet-dry tropical climate is characterized by: a warm climate but with a more marked temperature range during the high sun season, proximity to the ITC brings heavy rains during the cooler period, the subtropical high pressure cell produces very dry conditions vegetation adapts to the seasonality of rainfall and is described as rain-green because it enters a dormant period during the dry season and leafs out and blooms in the rainy season dramatic variations in rainfall are reflected in streamflow which varies from very low flows to flood-like conditions agriculture experiences periodic drought The dry tropical climate: is dominated by the Subtropical High Pressure Cell experiences very low precipitation and intense daytime heating under predominantly clear skies includes many of the world's great deserts semi-arid areas on the edges of the desert may have a short wet season. These steppe areas are transitional from the desert to the wet-dry tropical climate KEY TERMS wet equatorial climate intertropical convergence zone mE air mass mT air mass monsoon [ALREADY KEY TERM IN CHAPER 7] tradewind coast low latitude rainforest wet-dry tropical climate cT air mass subtropical high pressure cell raingreen vegetation throntree-tall grass savanna savanna woodland Sahel land degradation dry tropical climate highland climate STUDY QUESTIONS 1. Describe the annual temperature and precipitation patterns for the wet equatorial climate. 2. What atmospheric circulation factors dominate the wet equatorial climate? 3. Describe the annual precipitation pattern for the monsoon and trade wind coast climates. 4. How is the trade wind coast climate different from the monsoon climate? 5. Describe the annual temperature pattern of the tropical desert climate. 6. 7. 8. 9. What atmospheric circulation factors dominate the tropical desert climate? How have plants adapted to the tropical desert environment? How does climate impact agriculture and animal life on the savanna? How do temperature and precipitation change as elevation increases? CHAPTER QUIZ Multiple Choice Questions 1. In which of these low latitude climates does the ITC have least direct effect at the surface? a) wet equatorial climate b) monsoon and trade wind littoral climates c) wet-dry tropical climate d) dry tropical climate 2. The largest annual temperature range is found in the: a) wet equatorial climate b) monsoon and trade wind littoral climates c) wet-dry tropical climate d) dry tropical climate 3. Rainfall is abundant in every month of the year in the: a) wet equatorial climate b) monsoon and trade wind littoral climates c) wet-dry tropical climate d) dry tropical climate 4. The native vegetation of the wet-dry tropical climate is: a) the savanna b) the rainforest c) the grassland d) The desert 5. Which of the following pressure and wind systems plays a large role in the dry tropical climate? a) the intertropical convergence zone b) tropical easterlies c) the subtropical high pressure cells d) none of the above True/False Questions 1. Low latitude rainforests have the highest diversity of plants and animals on the Earth. (T/F) 2. Low latitude rainforests have soils that do not hold large amounts of the nutrients needed for modern agriculture. (T/F) 3. In all of the low latitude climates, the precipitation maximum corresponds with the low sun season. (T/F) 4. In desert climates, flash flooding is a serious hazard. (T/F) 5. The highland climates of the low latitudes experience colder and drier climates than the climates of surrounding locations at low elevations. (T/F) Short Answer Questions 1. What seasonal rainfall patterns are represented in the low latitude climates? 2. What would be the best time of year to vacation in Belize? Consult figure 8.4 in your text. 3. Why are temperatures lower in highland areas than in the surrounding lowlands? Short Essay Questions (1 - 2 paragraphs) 1. Describe the influence of the ITC and the subtropical high pressure cells on each of the low latitude climates. 2. How have humans adapted their agricultural practices to the variations in the low latitude climates? Internet Resources 1. Köppen Type A climates (Wet equatorial, Tropical monsoon and trade-wind littoral, Tropical wet-dry): <http://208.154.71.60/bcom/eb/article/4/0,5716,109114+6+106248,00.html> 2. Köppen Type B tropical climates (Tropical and subtropical desert, Tropical and subtropical steppe): <http://208.154.71.60/bcom/eb/article/4/0,5716,109114+8+106248,00.html> 3. Satellite views of the ITCZ: <http://Earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id= 4028> < http://visibleEarth.nasa.gov/cgi-bin/viewrecord?2100>