chapter 4Review
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In this chapter we have examined how global processes such as air and water currents determine regional climates and how these regional climates have a major effect on the types of organisms that can live in different parts of the world. Among the terrestrial biomes, temperature and precipitation affect the rate of decomposition of dead organisms and the productivity of the soil. Understanding these patterns helps us understand how humans have come to use the land in different ways: growing crops in regions with enough water and a sufficient growing season, grazing domesticated animals in drier areas, and harvesting lumber from forests. Among the aquatic biomes, differences in flow, salinity, and depth help to determine the aquatic species that can live in different aquatic regions of the world.
Module 9 The Unequal Heating of Earth
Identify the five layers of the atmosphere.
Above Earth’s surface, the first layer of atmosphere is the troposphere, followed by the stratosphere, mesosphere, thermosphere, and the exosphere.
Discuss the factors that cause unequal heating of Earth.
The unequal heating of Earth is caused by differences in the angle of the Sun’s rays that strike Earth, the amount of atmosphere that the Sun’s rays must pass through before striking Earth’s surface, and how much of the solar energy that reaches Earth is reflected rather than absorbed.
Describe how Earth’s tilt affects seasonal differences in temperatures.
Earth’s central axis is tilted at 23.5°, which causes seasonal changes in the latitudes that receive the most intense sunlight.
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Module 10 Air Currents
Explain how the properties of air affect the way it moves in the atmosphere.
Air rises when it becomes less dense and sinks when it becomes more dense. Warm air has a higher saturation point for water vapor than cold air. Changes in air pressure result in adiabatic cooling or heating; when water condenses it emits heat, which is known as latent heat release.
Identify the factors that drive atmospheric convection currents.
Atmospheric convection currents are driven by the intense sunlight that strikes Earth near the tropics. This solar energy warms the surface of Earth, which causes moist air to rise, cool, and release water as precipitation. As the air continues to rise, it reaches the top of the troposphere. The air, which is now cold and dry, moves toward the poles until it descends at approximately 30° N or 30° S latitude. As it descends back to Earth’s surface, the air warms and then moves back toward the equator.
Describe how Earth’s rotation affects the movement of air currents.
Because the surface of Earth travels faster near the equator than near the poles, the Coriolis effect causes convection currents traveling north and south to be deflected, thereby creating trade winds, westerlies, and easterlies.
Explain how the movement of air currents over mountain ranges affects climates.
When moist air from the ocean moves up a mountain, the air cools and releases water as precipitation, which results in a moist environment on the windward side. On the other side of the mountain, the cool, dry air descends, which results in a dry environment on the leeward side of the mountain.
Module 11 Ocean Currents
Describe the patterns of surface ocean circulation.
Ocean currents are driven by a combination of temperature, gravity, prevailing winds, the Coriolis effect, and the locations of continents. Together, prevailing winds and ocean currents distribute heat and precipitation around the globe.
Explain the mixing of surface and deep ocean waters from thermohaline circulation.
As ocean water flows from the Gulf of Mexico to the North Atlantic, water evaporates or freezes, and this causes the remaining water to have a high salt concentration and therefore a high density. This dense water sinks to the bottom of the ocean and later comes back to the surface near the equator.
Identify the causes and consequences of the El Niño–
The El Niño–
Module 12 Terrestrial Biomes
Explain how we define terrestrial biomes.
Terrestrial biomes are categorized by the dominant plant forms that exist in a region.
Interpret climate diagrams.
Climate diagrams illustrate monthly patterns of temperature and precipitation during the year. They also illustrate the growing season of a biome and the months during which plants are more constrained by temperature or precipitation.
Identify the nine terrestrial biomes.
The nine terrestrial biomes are tundra, boreal forests, temperate rainforests, temperate seasonal forests, woodland/shrublands, temperate grasslands/cold deserts, tropical rainforests, tropical seasonal forests/savannas, and subtropical deserts.
Module 13 Aquatic Biomes
Identify the major freshwater biomes.
There are three types of freshwater biomes. Streams and rivers have flowing fresh water. Lakes and ponds have standing water, at least some of which is too deep to support emergent vegetation. Freshwater wetlands are submerged or saturated by water for at least part of the year, but shallow enough to support emergent vegetation.
Identify the major marine biomes.
There are five types of marine biomes. Salt marshes are found along the coast in temperate climates and contain nonwoody emergent vegetation. Mangrove swamps occur along tropical and subtropical coasts and contain trees that have roots submerged in the water. The intertidal zone is the narrow band of coastline that exists between the levels of high tide and low tide. Coral reefs are found in warm, shallow waters beyond the shoreline and represent Earth’s most diverse marine biome. The open ocean is characterized by deep water where sunlight can no longer reach the ocean bottom.