Transcript 2-Factors Affecting Climate Change - Part 1

Factors That
Affect Climate
(page 5)
Deep Space is very cold  - 272oC
Earth is much warmer than that!
So where does the heat come from?
The Sun!
Effect of Distance from the Sun
Mercury
1/3 as far from sun as Earth
Mean daytime temperature +350oC
Pluto
40 times as far from sun as Earth
Mean daytime temperature -230oC
Does Earth’s distance from the sun vary?
yes, the orbit varies from circular to elliptical
an elliptical orbit means that the sun is closer at some
seasons than at others
this is referred to as eccentricity
Is the earth tilted on its axis?
Evidence?
Yes!
the seasons
the Northern Hemisphere gets more solar energy in
the summer and hence it is warmer then
Is this tilt constant?
No!
the tilt varies from 22.0o to 24.5o!
this change in tilt affect the energy arriving at
different parts of the Earth
Does the location on a sphere affect how much solar
radiation arrives at that place?
Yes!
The closer to the Equator, the more days the sun is directly
overhead,
The same
amount of
light energy
comes from
the sun
But that energy is
distributed over a
larger area as we
move away from
the Equator
The result is
that polar areas
are cooler than
Equatorial
areas
Does the atmosphere affect climate? How can we tell?
Well, the Earth and the Moon get the same amount of
energy from the Sun and yet…
Moon temperatures
Day  +110oC
Night  -150oC
Earth temperatures
Day  + 24oC
Night  + 16oC
So clearly the atmosphere has two effects
1. It keeps the earth cooler during the day
2. It keeps the earth warmer at night
How does it keep the earth cooler in the day?
The atmosphere acts as an umbrella to keep
some of the sun’s rays from reaching the Earth
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How does it keep the earth warmer at night?
The atmosphere acts like a blanket to keep
heat in.
Does the atmosphere affect other aspects of climate?
Winds!
What makes winds blow?
Air now cools away
from warm ground
Sun’s rays
warm the
ground
Warm, less
dense air is
pushed up
warm
Cool, more
dense air
falls
Surface winds move energy
around the planet
How else do winds affect climate?
Winds push ocean currents that also move energy
around the Earth
Volcanoes and climate
Volcanic ash rises high into the
atmosphere as it is hot
It blocks the sunlight from
reaching the Earth and so causes
cooling of the climate
It may also act as a nucleus for
cloud formation and increase
rainfall
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3
Places #1, #2 and #3 are all at the same latitude.
Yet they do not experience the same climate? Why?
Hydrosphere and climate
The atmosphere affects climate, what about the hydrosphere?
McGraw Hill pg 343 8- D
Comparing heat Absorption of Water and Soil