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ATMOSPHERE
Water cycle
Energy balance
Water and polarity
The hydrogen and
oxygen atoms are
joined by covalent
bonds (a strong bond
where electrons are
shared). The electrons
are not shared equally
so hydrogen has a
weak positive charge
and oxygen a weak
negative charge.
When two water molecules come together, the
positive side of one is attracted to the negative side of
the other, forming hydrogen bonds.
B (oxygen
atom) attracts
the electron
pair more than
A (hydrogen
atom) does.
SOLID, LIQUID AND GAS
Solid
The water molecules
are packed close
together preventing
ice from changing
shape.
Liquid
The water molecules
no longer cling
together as tightly
and individual
molecules can begin
to move around each
other.
Gas (water vapour)
The water molecules
move very rapidly
and are not bound
together. They are
still water molecules,
not individual atoms.
I am invisible
Maximum global
evaporation rates.
From "Global
Variations in
Oceanic
Evaporation
(1958–2005): The
Role of the
Changing Wind
Speed" by Lisan
Yu,WHOI OAFlux
project.
Electromagnetic radiation (EMR)
Electromagnetic radiation (EMR)
http://4.bp.blogspot.com/50TB_372KIk/T1U5U1TlVXI/AAAAAAAAAQ8/x
pSFhpCfr-g/s1600/solar-radiation.jpg
http://www.ecoedility.it/e3news/wpcontent/uploads/2010/05/bilacio_energetico_radiativo.jpg
A SURFACE LOOKS BRIGHT WHEN IT REFLECTS MOST OF
THE LIGHT THAT HITS IT.
IT LOOKS DARK WHEN MOST OF THE LIGHT IS ABSORBED.
A perfectly
white reflecting
surface has an
albedo of 1
A perfectly
black absorbing
surface has an
albedo of 0
Albedo
Reflectivity
of different
surfaces on
Earth
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arthlyissues.c
om/images/vi
talafrica_10threefactors_
large.jpg
Global winds
• Wind is the movement in air caused by differences
in wind pressure.
• The greater the difference, the faster the wind
blows.
• Differences in air pressure are cause by uneven
heating of the Earth
• Uneven heating produces pressure belts which
occur every 30 degrees latitude
• Hotter air is less dense and has a lower pressure
http://science.kennesaw.edu/~jdirnber/oceanography/Lecutu
resOceanogr/LecCurrents/0804.jpg
• As warm air rises (less dense) at the
equator and moves towards the poles it
cools
• As it cools some of the air sinks around 30
degrees north and south of the equator.
• At the poles cold air sinks and moves
towards the equator
• Around 60 degrees north and south the air
begins to heat up and rise
• The combination of pressure belts and the
Coriolis Effect causes global winds
• These are the:
– Polar easterlies
– Westerlies
– Trade winds
• Wind belts that extend from the poles to 60
degrees latitude are formed from cold
sinking air moving from the poles creating
cold temperatures
• Wind belts found between 30 and 60
degrees latitude flow towards the poles
from west to east carrying moist air
• Winds that blow from 30 degrees
almost to the equator are called the
Trade Winds.
• The doldrums are located along the equator
where no winds blow because the warm
rising air creates an area of low pressure.
• This is also called the ITCZ or Intertropical
Convergence Zone.
• At 30 degrees north and south are the horse
latitudes. Here the winds are very weak.
Most of the deserts on Earth are located here
because of the dry air.
• Jet streams are narrow belts of high speed
winds that blow in the upper troposphere are
lower stratosphere. The separate warm from
cold air.
http://www.srh.noaa.gov/jetstream/global/im
ages/jetstream3.jpg