Download Meteorology Study Guide

Meteorology Study Guide
Standard S6E4: Students understand how the distribution of land and oceans affects climate
and weather.
Element S6E4.a: Demonstrate that that land and water absorb and lose heat at different rates and explain the
resulting effects on weather patterns.
 Weather is the process in the atmosphere that changes over a short period of time.
 Climate is the weather that is in place most of the time or over a long period of time.
 Nearly all the energy in Earth’s atmosphere comes from the sun.
 Most of the energy from the sun reaches Earth in the form of visible light and infrared radiation, with a small
amount of ultraviolet radiation.
 Visible light is energy you can see.
 Earth changes infrared radiation into heat energy.
 Ultraviolet radiation causes sunburns, skin cancer, and eye damage.
 Some of the sun’s energy reaches Earth’s surface and is reflected back into the atmosphere.
 Some of the energy is absorbed by the land and water and changed into heat.
 Land heats up and cools down faster than water.
 Water heats up more slowly than land does, but holds the heat longer.
 Air heats up unevenly.
 Warm air becomes less dense and rises.
 Cooler air becomes denser and sinks.
 Wind that blows from an ocean or lake onto land is known as a sea breeze.
 The flow of air from land to a body of water is called a land breeze.
 Convection currents transfer heat from one place to another through a liquid or a gas.
 In Earth’s atmosphere, convection currents carry warm air upwards and cool air downwards.
 This is because of the uneven heating of Earth’s surface.
 Hugh chunks of warm and cold air are called air masses.
 Air masses move sideways across continents and oceans.
 Clouds and storms form when these masses run into each other.
 When a cold air mass meets a warm air mass, thunderstorms may appear.
Element S6E4.b: Relate unequal heating of land and water surfaces to form large global wind systems and
weather events such as tornadoes and thunderstorms.
 Wind is the horizontal movement of air from an area of high pressure to an area of low pressure.
 All winds are caused by differences in air pressure.
 Local winds are winds that blow over short distances.
 Local winds are caused by unequal heating of Earth’s surface within a small area.
 The unequal heating of Earth’s atmosphere by sunlight produces global winds.
 The combination of high-pressure polar air and low-pressure equatorial air produces global winds.
 The angle at which sunshine strikes Earth’s surface in MAINLY responsible for the unequal heating of
Earth’s surface.
 Air moves from areas of high pressure to areas of low pressure.
 Dense, high-pressure air over the poles sinks and moves towards the low-pressure air over the equator.
 Less dense, low-pressure air over the equator rises and moves toward the poles.
 These movements of air are global winds.
 Earth’s spin on its axis makes these winds move along a curved path (Coriolis effect).
 Northern Hemisphere global winds curve clockwise.
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Southern Hemisphere global winds curve counterclockwise.
Differences in air pressure can also produce powerful local winds and storms.
The low density, warm air will form clouds when it reaches colder air in the sky.
As low density moister rises high in the sky, it may freeze into particles that are electrically charged.
These charged particles can produce lightning and thunder.
Moist, low pressure air near the ground produce thunderstorms.
Thunderstorms form within large cumulonimbus clouds, also known as thunderheads.
Tornadoes are swiftly turning, very low-pressure funnels or air. They produce the fastest moving winds on
Earth.
Tornadoes develop in low, heavy cumulonimbus clouds.
Most likely to occur in spring and summer, often in the late afternoon when the ground is warm.
Tornadoes occur more often in the U.S. than in any other country.
Element S6E4.c: Relate how moisture evaporating from the oceans affects the weather patterns and weather
events such as hurricanes.
 Tropical storms are born over warm water near the equator.
 Very large and powerful tropical storms with spinning winds are called tropical cyclones.
 In the Atlantic Ocean and the eastern Pacific Ocean, tropical cyclones are called hurricanes.
 In the northwest Pacific Ocean, they are called typhoons.
 Energy from the sun warms ocean water.
 Energy absorbed by the ocean water causes the water on the surface to evaporate.
 The warm, evaporated water rises.
 This produces an area of low pressure called a tropical depression.
 This is when clouds begin to form.
 The air in the center of a depression in the Northern Hemisphere begins to spin counterclockwise.
 In the Atlantic Ocean, global winds push the storm westward.
 As the storm continues to move over warm water, heat from the water feeds it.
 As its air pressure drops lower its winds move faster and faster.
 A hurricane has a typical shape.
 The eye of a hurricane is a place of very low pressure with no clouds above it.
 In the eye, it is very calm and sunny.
 The most violent winds in a hurricane form the wall of the hurricane’s eye.
 Eventually, a hurricane will travel over cooler water or land.
 Once this happens, the hurricane can no longer feed on heat energy from warm water.