Transcript 10.3 Distributing the Heat p. 388 -396

10.3 Distributing the Heat
p. 388 -396
Energy from the sun radiates to the
Earth and is absorbed unequally on
the planet.
Why do some areas absorb more
radiation than others?
• Earth’s tilt on axis
Albedo effect
Ice, snow, clouds reflect
Darker land absorbs
How Oceans Effect Distribution of Heat
Large Reservoirs of Heat
1. Water has high specific heat capacity
2. Water has low albedo, high absorption (90%
of incoming solar radiation is absorbed
Large Reservoirs of Heat
• 3. High heats of fusion and vaporization
• 4. Water is a fluid and heat can be distributed
Ocean Currents
• Large effect on weather in coastal
communities
• Influence worldwide climate
Gulf Stream
• Surface current: starts in Caribbean and flows
up the Eastern coastline of US and Canada up
to British Isles. Also called North Atlantic
Drift.
El Nino
• Wind Direction over the South Pacific reverses
and winds flow eastward
• Heavy rains on west coast of S. America,
drought in SE Asia and N Australia
How does El Nino effect N America?
• While most of effects of El Nino are (-) (floods,
drought, famine) it does cause warming in
western N. America in winter months and a
decrease in intensity of Atlantic hurricanes
and tornadoes in Canada and US
What is La Nina?
• Increase strength of westward winds = cooling
of surface waters of eastern equatorial Pacific
• Warmer air to S Asia, Australia
Effects of La Nina in N. America
• Cold air from Alaska moves S across western
Canada and US (1996 LONG winter!)
• East becomes warmer and drier
Prevailing Winds
• Global winds that happen all the time.
4 main prevailing winds
• Polar easterlies, NE trade winds, SE
tradewinds, Westerlies
Convection Cells and Coriolis Effect
• Warm air expands, becomes less dense, rises from
Earth’s surface = area of low pressure
• Cold air contracts, becomes denser, descends to
Earth’s surface = area of high pressure.
• Air descends at 3 separate latitudes, 30o, 60o, Poles
Convection Cells and Coriolis Effect
• Earth rotates faster as move from poles to Equator
• This uneven rotation causes the convection currents
(and anything else in the atmosphere like airplanes,
missiles, space shuttles) to veer to the sideways!
Jet Streams
• Fast moving currents of air about 10 – 15 km
above the Earth’s surface, flowing W  E
• Polar jet stream affects Canada’s weather.
Forms at junction of polar easterlies and
prevailing westerlies.
Ocean Breezes p. 394
• Daytime: land heats up faster than water, sets
up convection current, air blows towards
shore = “sea breeze”
• Nighttime: water cools more slowly than land,
air blows towards ocean = “land breeze”
Orographic precipitation
• Warm, moist air cools, condenses as it rises
against the mountains, precipitates.
• W coast – Vancouver
• We are in the rain shadow – so Alberta is
much drier