Study Guide – Test 2/15/2011 o
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Ocean Currents Surface currents are caused by strong winds blowing over the ocean. They curve with the rotation of Earth They carry warm water away from equator and cool water away from the poles They effect Earth’s temperatures Climate and Weather Currents help distribute heat around the globe by moving warm and cold water around. The moving water changes the temperature of the air above it.
Sea Breeze and Land Breeze Specific Heat Substances with a high specific heat warm and cool slowly. o They take more energy to change temperature Substances with a low specific heat warm and cool quickly. o They take less energy to change temperature Water has a high specific Heat Sand (Land) has a low specific heat During the day…Sea Breeze How does a breeze in the middle of a hot day feel? o The SAME amount of heat energy hits the land and the water on Earth, but water has a higher Specific Heat than land. The Land gets Hot much Faster than the water. The Air that touches the land gets warm through conduction. The Air over the ocean stays cooler. Because Warm air is less dense than cold air, convection occurs. The warm air will rise up allowing the cool air over the ocean to come in to the land This feels like a cool breeze from the ocean called a Sea Breeze. (It’s named by where it comes from) We learned from Specific Heat that water warms slowly, AND cools slowly. At night when the sun goes down, the land cools very quickly because it has a low specific heat. The ocean stays warm because it has a high specific heat and holds onto the heat longer. The convection Current in the air is now reversed. The warm air over the water rises, and the cold air over the land moves in over the ocean to replace the warm air. A cool breeze would pass over the ocean called a LAND BREEZE.(Again, named by where it comes from) Air Mass Notes An air mass is an extremely large body of air whose properties of temperature and moisture content (humidity), at any given altitude, are fairly similar.
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Air masses can cover hundreds of thousands of square miles. Air mass source regions are geographic areas where an air mass originates. Source regions could be over land or water.
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The longer the air mass stays over its source region, the more likely it will acquire the properties of the surface below.
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Continental -located over large land masses-dry
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Marine-located over the oceans-moist
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Tropical latitudes are typically located within about 25 degrees of the equator.
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Polar latitudes are typically located near the poles of 60 degrees north and south or more.
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Four combinations of air mass: o cT – Continental Tropical – dry and warm o mT-Maritime Tropical-moist and warm o mP-Maritime Polar–moist and cold o cP-Continental Polar–dry and cold
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Air mass in the U.S. o cP–Begins in Canada, just North of US border, and moves South towards The Great Plains. Bitterly cold and dry! o
mP–Begins in Pacific Ocean off the coast of Alaska and moves Southeast towards Washington & Oregon. Very cold but with lots of moisture.
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mT–Begins off the coast of either Florida or Baja California. The air masses move North toward towards either coast and inland passing over California and Florida as they move. Very warm with lots of moisture.
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cT-Begins over Mexico and moves North passing over Texas. The air is warm but very dry.
Topographic Maps Notes A topographic map is a map that shows surface features, or topography, of Earth Elevation is an object's height above sea level. The elevation at sea level is zero. Contour lines are lines that connect points of equal elevation. Example: One contour line would connect points on a map that have an elevation of 100 ft. Another line would connect points on a map that have an elevation of 200 ft. Contour lines that are close together show a steep slope. Contour lines that are spaced apart show a gentle slope. The difference in elevation between one contour line an the next is called the contour interval. Example: A map with a contour interval of 20 ft would have contour lines every 20 ft. of elevation change, such as 0ft, 20 ft, 40 ft, and so on. Index contour lines are darker, heavier contour lines that are usually every fifth line and are marked by elevation. The contour lines falling between the index contour lines are called intermediate contour lines. These lines are finer and do not have their elevations given. There are normally four intermediate contour lines between index contour lines. Supplementary contour lines resemble dashes. They show changes in elevation of at least one-half the contour interval. These lines are normally found where there is very little change in elevation, such as on fairly level terrain. Relief is the difference between the highest and lowest points of the area being mapped.