Unit 3 Biomes

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Unit 3Biomes

• Chapters 7 8

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Weather

• ______________ atmospheric conditions
• Over __________________

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How do we describe weather?

• Temperature
• Pressure
• Moisture content
• Precipitation
• Sunshine
• Cloud cover
• Wind speed and direction

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Weather equipment

• Balloons
• Satellites
• Aircraft
• Ships
• Radar
• Sensors
• Computer models

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Weather Maps
Isotherms thin black lines that separate areas
of different temperatures
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• Isobar thick lines that connect points with the
  same barometric pressure.
• High-pressure system (red "H)
• Low-pressure system (blue "L)
• Cold front (blue line with triangles) The
  triangles point in the direction toward which the
  cold front is moving.
• Warm front (red line with semi-circles) The
  semicircles point in the direction toward which
  the warm front is moving.
• Stationary front These are shown on weather maps
  as alternating triangles and semicircles.

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How does weather change?

• When air masses meet at a front
• Front-

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Weather Fronts

• Cold Fronts (associated w ____________)
• Edge between an advancing _____ air mass a
  __________ one
• More dense
• Lower to ground
• Faster moving
• Wedge up under the warmer air mass
• Shifts winds from southeast to northwest
• Causes storms cooler temperatures

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Weather Fronts

• Warm Fronts (associated with ____________________)
  
• Edge between advancing ________ air mass a
  ___________ one
• Less dense
• Causes fog if stable
• Shifts winds from southeast to southwest
• Causes light rain warmer temperatures

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Air Pressure

• Caused by gas molecules moving around the
  atmosphere

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Low Pressure

• Wind circulates _____________________ around
  low-pressure systems in the northern hemisphere
  (opposite in the southern hemisphere)
• Center of the mass rises, expands and cools down

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High Pressure

• Wind circulates _____________________ around
  high-pressure systems in the northern hemisphere
  (opposite in the southern hemisphere)

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Jet Streams

• Powerful winds in upper ______________
• Strongly influence weather patterns

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Dew Point

• The temperature where water vapor condenses and
  becomes liquid
• Associated with relative humidity

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Tornadoes

• Swirling funnel clouds that form over land

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Tornadoes

• Forms from a cumulonimbus
• touch the ground
• Winds
• Travel only

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Tornado Alley

• Large, dry, cold air front from Canada moves
  south and interacts with a large humid mass
  travelling north from Gulf of Mexico
• Large warm air mass moves rapidly over the dense
  cold air
• Warm air rises rapidly and causes vertical
  convection currents to form that sucks the air up

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Tornadoes

• (Enhanced) Fujita Scale

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Tropical _________________

• Low pressure air masses over
• Long time to form and strengthen
• Easy to track

??? ?
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Hurricane or Typhoon?

• Hurricanes form in the
• Typhoons form in the

????
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Hurricane Formation
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Hurricanes

• Warm moist air spiral into the center of the
  storm and are sucked upward
• Rising air cools and leaves the storm at high
  altitudes

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Climate

• ____________________ atmospheric conditions
• Average
• Average
• Varies due to

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Factors in Air Circulation

• 1. Uneven _________________ of the Earths
  surface
• Directly hits equator
• Hits poles at an angle
• 2. ______________________________ in temperature
  and precipitation

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Factors in Air Circulation

• 3. _______________________________
• Surface turns faster at the equator and slower
  at the poles
• Causes winds to deflect (___________)

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Factors in Air Circulation

• 4. Properties of air, water, and land affect
  circulation
• How land, water, and air heat differently
• Convection

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Convection

• Hot air is less dense, it
• Cool air is more dense, it

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Convection Cells

• Directly influence air and water currents

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Ocean Currents

• Warm air moves over the surface of the water
  transfers energy to the water
• Ocean water has different densities due to
  differences in ______________ _________________
• Combine to create __________________

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Ocean Currents

• Redistribute solar energy
• Influence climate and vegetation
• Mixes water to redistribute nutrients and
  dissolved oxygen (DO)

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Upwelling

• Cool, nutrient rich waters are drawn
  ______________ to replace warm surface waters
• Surface waters are usually displaced by wind
• Bring ______________ to shallow regions

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Upwelling
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ENSO

• El Niño Southern Oscillation
• 1997-1998 El Nino Event
• Can cause extreme global weather changes

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La Niña

• Opposite of ENSO
• Causes more hurricanes, colder winters, wildfires
  in FL

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Greenhouse Effect
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Greenhouse Effect

1. Solar energy enters the atmosphere
2. Solar energy hits something on the Earths
   surface and passes some of that energy to the
   object
3. Solar energy tries to escape the atmosphere but
   no longer has enough energy so it is trapped

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Greenhouse Effect

• Humans are adding greenhouse gases through
  activities such as driving cars, burning fossil
  fuels, cutting down trees

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Greenhouse Gases

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Rain Shadow Effect
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Rain Shadow Effect

• Warm moist air hits a
• Air is forced upwards where it cools and is
  forced to release its moisture
• Creates one side of the mountain that has
• Other side of mountains are