Energy and Motion in the Atmosphere

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Energy and Motion in the Atmosphere

• Energy and the Atmosphere
• Air Movement
• Hazardous Weather

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Energy and the Atmosphere

• The sun is a major source of energy for the
  atmosphere. Energy that travels from the sun to
  the earth in the form of waves is called
  radiation.
• The most familiar kinds of radiation are visible
  light and heat. Some of the radiation from the
  sun is reflected back into space by the
  atmosphere. The radiation that reaches the
  earths surface is reflected or absorbed. The
  energy that is absorbed by the earth is changed
  to heat, which is then given off by the earth.

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Absorption and Reflection of Radiation from the
Sun
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Energy and the Atmosphere

• Weather is caused by the uneven distribution of
  energy in the atmosphere. The energy that heats
  the atmosphere comes mainly from the earth. The
  warmer the ground, the warmer the atmosphere over
  it.
• Because the earths surface is curved, the suns
  rays strike the surface at many different angles.
  Therefore, the amount of radiation received by
  the earth differs from one location to another.

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The amount of radiation received by the sun is
greatest around the equator and least around the
poles.
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Energy and the Atmosphere

• The area around the earths Equator receives the
  most direct rays from the sun, so the weather
  near the Equator is warm. Near the poles, the
  radiation from the sun strikes the earth at a
  greater angle and is spread out over a large
  area.
• Regions near the poles are cold. On a daily
  basis, the suns rays are most direct (strongest)
  at local noon. On a yearly basis, the rays are
  strongest during summer months.

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Image from the North Pole (arcticnoaa.gov)
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Uganda at the Equator
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Air Movement

• The main cause of winds in differences in air
  pressure from one area to another. Air moves
  from regions of high pressure to regions of low
  pressure.

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Air Movement

• Currents- Cold air is heavier (more dense) than
  warm air. As a result, cold air is pulled down
  by gravity and sinks. When cool, dense air sinks
  in one place, it pushes up warm, less dense air
  somewhere else.

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Air Movement

• Currents (patterns of air flow) develop in the
  atmosphere when cold air sinks in one place, then
  flows to a region of lower pressure and rises.

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Air Movement

• Planetary Winds- the rotation of the earth and
  uneven heating of the surface result in a series
  of wind pressure belts known as the planetary
  wind system.

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Air Movement

• The main reason HIGHS and LOWS move across the
  United States from west to east is that we are
  located in a belt of planetary winds that blow
  from west to east.

Where is the United States?
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Air Movement

• Local Winds- on a smaller scale than the
  planetary winds, unequal heating of the earths
  surface along seashores produces local winds
  called land breezes and sea breezes. In the
  mountains, valley breezes and mountain breezes
  are produced.

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Hazardous Weather

• Everyone is likely to experience hazardous
  (dangerous) weather at some time in their lives.
  Hazardous weather includes severe thunderstorms,
  tornadoes, hurricanes, and blizzards.

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Hazardous Weather

• The government has developed a number of warning
  system to inform the public of hazardous weather.
• A weather watch indicates that hazardous weather
  conditions may occur in the next 24 to 36 hours.
• Warnings indicate that hazardous conditions are
  about to occur. When people prepare for and
  respond to dangerous weather conditions, lives
  and property are saved.

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Hazardous WeatherThunderstorms

• Thunderstorms are violent, small-area storms that
  usually occur in the summer. They form along
  fronts when warm, moist air rises quickly and
  condenses
• Lightening is a large electric spark that jumps
  between a cloud and the ground. Heat from the
  lightening causes the air to expand. The
  molecules of the air bump against each other with
  such force that sound- thunder- results.

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Hazardous WeatherTornadoes

• Tornadoes are the most violent and dangerous kind
  of storm. A tornado is a funnel of rapidly
  spinning air that reaches downward from a storm
  cloud. A tornado begins when a rapid up flow of
  wind occurs. In the area beneath the up flow,
  the air pressure becomes very low. Air rushing
  into this low-pressure area gains speed and spins
  upward. Winds in tornadoes can reach speeds of
  300 km per hour! Tornadoes occur mainly on warm
  spring and summer days.

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A Tornado and a rain storm
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Hazardous WeatherHurricanes

• Hurricane- a huge whirling storm around a
  low-pressure area. Hurricanes form near the
  Equator. They begin when warm, low-density air
  starts to rise over a low-pressure center. Winds
  carrying fresh moisture rush into this
  low-pressure center. The air begins to spin in a
  counter-clockwise direction. As the moisture
  condenses, the storm grown larger, forming a
  hurricane.

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Hurricane
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Hazardous WeatherHurricanes

• The low-pressure center of the hurricane called
  the eye, is very calm. Just outside the eye, the
  winds and precipitation are most severe. The
  winds in a hurricane can reach speeds of more
  than 200 km per hour. The diameter of a
  hurricane, is about 500 km, is much larger than a
  tornado. The hurricane season for the east
  coast of the United States is from August through
  October.

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Hurricane Katrina
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Hazardous WeatherWinter Storms

• Winter storms bring snow, ice and low
  temperatures that are hazardous. A sever snow
  storm is a blizzard.

Blizzard of 2006 in Bryant Park in NYC
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Questions

• Natural pollutants include ______________ from
  volcanoes and ___________________ from plants.
• Pollutants are removed from the atmosphere
  naturally by _____________________.
• The control and reduction of pollutants are the
  responsibility of __________________.

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Questions

• The main source of energy for the earth is the
  ___________________.
• Radiation is energy that travels from the sun to
  the earth in the form of _________.
• Radiation from the sun is ____________ or
  __________ at the earths surface.

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Questions

• 4. The distribution of energy in the atmosphere
  is uneven because the earths surface is
  ______________.
• 5. The warmer the ground, the _____________ the
  atmosphere over it.
• 6. The uneven distribution of energy in the
  atmosphere is the cause of ___________.

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Questions

• 7. In the course of a day, the suns rays are
  most direct at ___________________.
• 8. Some radiation from the sun is reflected back
  into space by ____________ and _____________.
• 9. Some radiation from the sun is absorbed by
  ______________ and ___________.

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Questions

• The main cause of winds is differences in
  _________________ from one region to another.
• Air blows from regions of ______________ pressure
  to regions of _______________ pressure.
• When cold, dense air sinks in one place, It
  pushes up ___________ air in another place.

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Questions

• 4. The planetary wind system is caused by the
  __________ and _______________ of the earth.
• 5. Examples of local winds are __________ and
  ________________.

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Questions

• Lightning is an electric spark that jumps between
  a cloud and the ___________.
• The most violent kind of storm is a
  _________________.
• A tornado is a _______________ of rapidly
  spinning air.

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Questions

• 4. A hurricane is a huge whirling storm around a
  ___________ - pressure area.
• 5. Hurricanes generally form near the
  _______________.
• 6. The center of a hurricane is called the
  ________.