Transcript Solar energy is concentrated near the equator

Chapter 4
Global Climate and Biomes
Unequal Heating of the Earth
Regions near the equator
(0o) receive light at 90o
High latitudes receive light
at low angles
1. Sun rays travel shorter
distance to equator
(energy is lost the
farther it travels)
2. Sun rays distributed
over smaller area (more
concentrated)
3. Albedo
Earth
Solar energy is concentrated near the equator
Image: Netherlands Center for Climate Research
Energy
absorbed solar
energy
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Latitude
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absorbed solar
energy
Energy
Emitted IR
energy
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Latitude
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More energy is absorbed near the equator than emitted
And more energy is emitted near the poles than is absorbed.
absorbed solar
energy
Energy
Emitted IR
energy
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Latitude
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Energy
net radiation
surplus
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Latitude
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Excess energy at the equator is transferred towards
the poles by convection cells
Energy
net radiation
surplus
net radiation
deficit
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Latitude
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Solar energy received is greatest near the equator.
Energy is moved from the equator to the poles.
Solar Energy
Solar energy received is greatest near the equator.
Energy is moved from the equator to the poles.
Energy is transferred by wind and ocean currents
Hadley Circulation Cell
solar radiation
Air near the equator is warmed, and rises
Hadley Circulation Cell H
solar radiation
The rising air creates a circulation
cell, called a Hadley Cell
Rising air  low pressure
Sinking air  high pressure
H
L
H
Hadley Circulation Cell
Rising air is replaced
Warm air rises
Hadley Circulation Cell
Air cools, sinks
Rising air is replaced
Warm air rises
Hadley Circulation Cell
Air cools, sinks
Rising air is replaced
Warm air rises
HIGH
LOW
HIGH
Rising air cools; the
air’s capacity to hold
water drops. Rain!
Air cools, sinks
No rain in
regions
where
air is
descending
Rising air is replaced
Warm air rises
HIGH
LOW
HIGH
The Coriolis Effect
• Rotation of the Earth leads
to the Coriolis Effect
• This causes winds (and all
moving objects) to be
deflected:
– to the right in the Northern
Hemisphere
– to the left in the Southern
Hemisphere
What makes Venus different?
The Coriolis Effect
Based on conservation of angular momentum
We experience linear momentum when we are in
a car that is traveling fast and then stops suddenly.
Planet Earth rotates once per day.
Objects near the poles travel slower than those near
the equator.
Objects near the poles have less angular momentum
than those near the equator.
When objects move poleward, their angular
momentum causes them to go faster than the
surrounding air. Conversely, they slow as they move
towards the equator.
When objects move north or south, their angular
momentum causes them to appear to go slower or
faster.
This is why traveling objects (or air parcels) deflect to
the right in the northern hemisphere and to the left in
the southern hemisphere.