Weather

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Weather

• Everything you ever wanted to know about the
  weather
• Ramsey 2006

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Meteorology

• Meteorology is the study of the atmosphere and
  the atmospheric phenomena
• Meteor- is from ancient Greek and means high in
  the air
• ology means the study of
• A meteorologist- one who studies the weather

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Why Does Weather Occur?

• All weather results from the attempt to balance
  out the uneven distribution of solar energy on
  Earth
• More energy at equator
• Less energy at the poles

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Weather vs. Climate

• Weather is the current state of the atmosphere
• Look out the window that is the weather
• Climate is the average weather over a long period
  of time.
• What does it feel like most of the time?

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I. Moisture in the AirEvaporation and
Condensation

• 1. Most water comes from tropical oceans. Warm
  water forms water vapor faster because molecules
  move faster.
• 2. Saturated air- air filled with as much water
  as it can hold. Over ocean, the wind blows
  moisture away so evaporation continues.
• 3. Humidity- amount of water vapor in air
• 4. Absolute humidity- actual amount of water
  vapor per cubic meter of air.
• 5. Relative humidity- percent of saturation the
  higher the relative humidity, the slower the
  evaporation.
• 6. Humiture- the combined effect of heat and
  humidity.

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II. Clouds and PrecipitationTypes of Clouds

• 1. Cumulus- forms when hot, humid air rises
  forms cumulonimbus in the summer called
  thunderheads
• 2. Stratus- layers of clouds that cover the sky-
  nimbostratus thick clouds that form snow or
  rain.
• 3. Cirrus- highest in troposphere, made of ice
  crystals, look like thin, wispy filaments.

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B. Precipitation

• Solid, liquid water that falls to the Earth
• rain
• snow
• Sleet
• hail

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III. Frontal Weather

• A. Air Masses and Fronts
• 1. Air mass- large body of air with nearly
  uniform temperature and humidity.
• 2. Front- when different air masses meet, surface
  between the air masses creates the front.
• a. cold
• b. warm
• c. stationary
• d. occluded- cold air moves faster than
• warm air, warm air forced upward

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Clouds Cumulus
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IV. Condensation and Dew point

• 1. Warm air of day holds more water vapor than
  cooler night air.
• 2. Relative humidity may reach 100 if
  temperature falls, water vapor changes to liquid
  condensation.
• 3. Dew point- temp. at which dew forms it
  changes depending on relative humidity.
• If the dew point is below 0 C, frost forms
• 4. when warm air rises, it cools relative
  humidity rises, causing water vapor in the air to
  condense.
• 5. Aerosols- dust, smoke, salt crystals, and air
  pollutant act as nuclei.
• (condensation nuclei) for condensation.
• 6. Clouds- collection of water droplets in
  atmosphere.
• 7. Fog- a cloud that forms near the ground.

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V. Violent Weather

• Thunderstorms
• Lightning
• C. Tornadoes
• D. Hurricanes
• E. Cyclones

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Thunderstorms

• 1. Violent storms that develops from
  cumulonimbus. thunder heads
• 2. Lightning- stroke of electricity negative
  charge attracted to positive charge of ground.
• 3. Use lightening rods to connect to ground.

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Tornadoes

• 1. Small extreme violent storm occur when two
  very different air masses collide and circulate
  around low pressure- counter clockwise called
  cyclones in Northern Hemisphere.
• 2. Squall Line- forms when warm humid air rises
  above ground.
• 3. Water spout- vortex that occurs over water.
• Fujita Scale
• 0-1 weak, 2-3 strong, 4-5 devastating

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Hurricanes

• C. Hurricane- large storm that occurs over
  tropical water.
• Saffir- Simpson scale
• 1. tropical depression- results when south trade
  winds collide with north trade winds.
• 2. Eye- core of the warm air highest winds
  circle around the eye.

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Cyclones

• 1. cyclones- all weather systems that circulate
  around low pressure centers.
• a. Northern hemisphere- counter clockwise
• b. Southern hemisphere- clockwise
• 2. They get energy from heat released by
  condensation.
• 3. Anticyclones- circulation around high pressure
  systems opposite of cyclone.

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Climate

• Climate- combination of all weather conditions
  that characterize a region.
• 1. temperature and humidity- measured by
  psychrometer
• 2. number of hours of sunlight.
• 3. amount of cloudiness
• 4. amount of precipitation
• 5. latitude and altitude
• 6. wind speed and direction
• Isotherms- temp.
• Isobars- press.

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Climate Zones

• tropical
• polar
• c. temperate