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B. Dry Climates – Middle Latitude PowerPoint Presentation
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B. Dry Climates – Middle Latitude

B. Dry Climates – Middle Latitude

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B. Dry Climates – Middle Latitude

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  1. B. Dry Climates – Middle Latitude Middle Latitude Middle Latitude

  2. C. Moist, Mild Winter Climates – Middle Latitudes Middle Latitude Middle Latitude The major differences among the three kinds of climate is TEMPERATURE.

  3. D. Moist, Cold Winter Climates High Latitude Middle Latitude Middle Latitude High Latitude

  4. E. Polar Climate – High Latitudes High Latitude High Latitude

  5. How does El Nino Work? Under normal conditions (above left), reliable winds blow from South America, westwards across the Pacific Ocean, towards southern Asia and Australia. This causes the water to heap up on the western side, so that the sea level is 0.5metres higher! As the warmer water is water is shifted, cooler water rises to replace it. This water is rich in nutrients from the ocean’s bottom. During El Niño (above right) the winds become weaker, resulting in the warm water layer in the west becoming shallower and creating a deeper warm water layer in the east. This prevents the upwelling of the cooler water and nutrients off the South American coast, and affects the food chain.

  6. Why is El Niño significant? The upwelling of the cool water is switched off, the supply of nutrients for food chains is decreased. The consequence of this is to reduce the productivity of the area, so there are fewer phytoplankton [small plants] and a smaller biomass for animal life. An economic consequence is that the fish stocks are reduced. The name El Niño means the Little Boy or Christ Child in Spanish. It was used because the event often occurred around Christmas time. Fishermen recognized it from the appearance of warmer than usual water which they could link with the prediction of reduced catches later in the year. As the energy focus is shifted eastward, the rainfall in the west is reduced. This affects both continents, Australia and Indonesia can experience severe drought and forest fires. In South Africa, Peru may experience severe rainfall and flooding. On a wider scale, the influence of such a large shift in one component of the climatic system, can be felt beyond the immediate vicinity of the South Pacific. You can find the outcomes of gathered data and an animation of an El Niño at the following web site:

  7. VI. Impact of People on Climate • Changing Earth’s Surface 1. Deforestation a.) Agriculture has led to deforestation. 1.) 40% of the earth’s rainforests have been cleared. 2.) loss of forests means the loss of a great many plants and animals. 3.) loss of plants – less water in the air more carbon dioxide. 4.) climates all over the world would slowly change.

  8. 2. Desertification a.) People’s actions are changing earth’s surface by increasing the number of dry climate areas. b.) Arable landis becoming desertand this is called desertification. (What is arable land?) 1.) Semiarid land is not being used properly. 2.) each year millions of acres of Earth’s surface becomes desert.

  9. 3. Urbanization a.) Concrete takes the place of trees and other plants. b.) tall buildings change wind patterns. c.) air is polluted by heavy industry, cars, buses, etc. d.) air becomes harder for people to breathe….because they have… 1.) polluted the air 2.) created acid rain

  10. Why Climates Change • Changes in the Sun • Changes in Earth’s Orbit and Axis • Space Dust • Meteorites • Continental Drift • Volcanic Eruptions • People’s actions????