Section 4.2

1. Section 4.2 Earth has a variety of climates

2. Vocabulary • Climate zone: one of the major divisions in a system for classifying the climates of different regions based on characteristics they have in common. • Microclimate: climates of smaller areas within a subclimate. • Urban heat island: a warmer body of air over a city. • Rain shadow: an area on the downwind side of a mountain that gets less precipitation than the side that faces the wind.

3. Climate Zones • The most widely used climate classification system groups climates by temperature and precipitation. • Six major climate zones include: • Humid tropical • Dry • Moist mid-latitude with mild winters • Moist mid-latitude with severe winters • Polar • highland

4. Humid Tropical • Tropical Wet: high temperatures throughout the year, humid air causes heavy cloud cover and abundant rainfall and no dry season (annual rainfall is more than 2.5 m). EXAMPLE: Amazon Rain Forest • Tropical Wet & Dry: Hot and rainy but have a dry season in the winter. EXAMPLE: Miami, Florida

5. Dry • Desert: Precipitation infrequent and scanty (usually less than 20 cm of rain per year), include some of the hottest places on Earth but can be cool (especially at night). EXAMPLE: Phoenix, Arizona • Semiarid: Found next to deserts and have wider temperature ranges than deserts and are not as dry. EXAMPLE: Denver, Colorado

6. Moist Mid-Latitude with Mild Winters • Humid subtropical: Summers are hot and muggy, winters are usually mild, and precipitation is fairly even throughout the year. EXAMPLE: Charlotte, NC • Marine west coast: Mild temperatures year-round and steady precipitation with low clouds and fog. EXAMPLE: Seattle, Washington • Mediterranean: Dry summers and mild wet winters, some coastal areas have cool summers and frequent fog. EXAMPLE: San Francisco, CA

7. Moist Mid-Latitude with Severe Winters • Humid continental: Hot summers and cold winters, precipitation fairly even throughout the year, snow covers the ground 1-4 months in winter. EXAMPLE: Des Moines, IOWA • Subarctic: Temperatures usually stay below freezing for 6-8 months, summers brief and cool, low precipitation but snow stays on the ground for long periods of time. EXAMPLE: Fairbanks, Alaska

8. Polar • Tundra: Average temperature of the warmest month is below 10*c, a deep layer of soil is frozen year-round (permafrost) and turns muddy in the summer as it thaws. EXAMPLE: Barrow, Alaska • Icecap: Surface is permanently covered with ice and snow, temperature rarely rises above freezing. EXAMPLE: Antartica

9. Highland • Because temperature drops as altitude increases, mountain regions can contain many climates, tall mountains may have year-round covering of ice and snow at their peaks.

10. Microclimates • Microclimates can be as large as a river valley or smaller than a garden. • Forests, beaches, lakes, valleys, hills, and mountains are some of the features that influence local climates.

11. Urban Heat Islands • Urban Hot Pocket • Artificial surfaces (concrete, buildings, etc.) have a tendency to absorb more solar energy (radiation) than grass, trees, and soil. Also, these surfaces absorb less water and there is less cooling from evaporation. Lastly, cities use a lot of energy for cooling, transportation, and other activities. This releases heat into the atmosphere. • http://www.youtube.com/watch?v=lnBO4vX82Fs

12. Rain Shadow • Air is forced to rise as it flows over a mountain • As the air rises and cools, it condenses into clouds • Areas that face the wind may receive a lot of precipitation • After passing the mountain, air is much drier because it has lost moisture through condensation and precipitation • http://www.youtube.com/watch?v=_hzXri71sMM