GEOL 1110 Lecture 2: Earth's Atmosphere and Interior
3 Jul 2018
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Department
Course
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Earth’s Atmosphere and Interior
ATMOSPHERE
The Atmosphere
Exists between the earth’s surface and up to 10,000km off the Earth’s surface
oThey are held there by the Earth’s gravitational pull
oThe closer you are to the surface, the concentration of molecules is higher
because it pulls more molecules
oThe further you are off the surface, there is a lower density of molecules
Baumgartner reached an altitude of 39km with an estimated speed of
1357.6km/h jumping from the stratosphere, which made him the first man to
break the speed of sound in freefall and set several other records while delivering
valuable data for future space travel
oHe was able to do this because there was so little air and molecule
resistance to slow him down
Realistically, we call up to 500km off the surface part of our atmosphere because
up to 10,000 is so few and far between particles or molecules
Atmospheric Composition
oHeterosphere LAYERS of gasses Hydrogen, Helium, Oxygen,
Nitrogen,
oHomosphere BLEND of gasses
Atmospheric Temperature each layer has different temperature See chart
in Prezi!!
oThermosphere
oMesoshere
Mesopause
Fewer collisions between the molecules so therefore there is very
little heat
oStratoshere
Stratopause
Fewer collisions between the molecules so therefore there is very
little heat
oTroposhere where we live, holds in heat, has a mixture of gasses
Goes up and we hit the troposphere, which differentiates the two
from the stratosphere
Because there are more molecules in the air here, more heat is
generated by molecules crashing together
Atmospheric Function
oHydrogen and Helium ignite and light up when they are hit with solar
winds in the upper atmosphere therefore making Auroras
oOzone absorbs the rays and therefore prevents skin cancer
oUV Radiation is absorbed by Ozone, which means that less UV is getting
to the surface of the earth therefore we cannot see the UV rays because
it is absorbed by the Ozone
find more resources at oneclass.com
find more resources at oneclass.com
If we don’t have enough Ozone, too much UV rays get to the
surface
It has detrimental effects on humans Skin cancer
Atmosphere is made up of lots of molecules, we can see that certain wave
lengths that are able to pass between the molecules visible light, whereas if the
waves are absorbed, they are not visible
The Atmosphere: Profile
Air Pressure changes throughout the atmospheric profile
oAir molecules create air pressure through their motion, size and number,
exerting a force on all surfaces they come in contact with
oSimilar pressure exists within us, pushing outwards
Earth’s atmosphere exerts weight (presses downward)
oPresses down due to gravity
The weight= force exerted per unit are
oAverage force=1kg cm-2 or 101.32 kPa
oAnything other than this is high or low-pressure systems
oHigh pressure systems (weather) is when it is sunny and warm because
so many collisions and therefore heat is released and there are less
clouds because it can hold more water vapor
oLow pressure systems make clouds and therefore rain (often)
Higher up (Ex. Mt. Everest) there is less air pressure and less density so there is
pressure on you
Half of all atmospheric gas exists below 50km in altitude
Pressure decreases by 50% for every 5.6 km above sea level
oThat’s why the air is so “thin” on top of Mt. Everest
Heterosphere
Outer atmosphere
oAltitude 80-480km
oLess than 0.001% of the atmospheric mass is found here
Gasses are not evenly mixed, hence Hetero
oOrganizd into layers depending upon the atomic weight of the gas
oHelium and Hydrogen lay above Oxygen and Nitrogen
Location of ionosphere
Homosphere
Sea level to 80 km
Gasses are uniformly blended- almost
oException –ozone 19-50km
oException—pollution and trace elements found in lower atmosphere
The Atmosphere is primarily made of Gasses
o78% Nitrogen
o20% Oxygen
find more resources at oneclass.com
find more resources at oneclass.com
oArgon, Neon, Helium, water vapor and other things are in trace ammounts
in the atmosphere
Air pressure increases towards Earth
oBlended gasses- air is composed of stable ingredients
oPromarily
Nitrogen – not breathe, but fixed
Oxygen—by product of photosynthesis
Argon – inert, but critical to tech
CO2 -greenhouse gas
Water vapour -critical to hydrological cycle
The sun emits short wave radiation, the earth absorbs it, the earth emits long
wave radiation is absorbed by things like CO2, methane, SO2 ,(Greenhouse
Gasses)
oLately, we have been creating more greenhouse gasses from industrial
activities, cows, cars, etc.
oThey start absorbing the long wave radiation (they get excited and they
emit heat) so it takes LONGER to get into the atmosphere
oAka Global Warming and Climate Change
oShort wave radiation is absorbed as heat
oBy preventing long wave radiation this we are STORING more energy
Wind and Clouds
Clouds are composed of water
oIn the troposphere
Clouds are evidence of the changes in air pressure (wind) and the presence of
water vapor
Wind moves in both horizontal (advection and vertical (convection) directions
If there is a very high and a very low-pressure system together, there is going to
be a lot of wind, If there are two very similar pressure systems, there will be no
wind
Warm air can hold more water vapor so there is less clouds
Cool air holds less water vapor so the water molecules congeal together into
clouds, or sometimes FOG
oOften near bodies of water which are WARM there is a lot of fog
oWarm air from above water with water vapor in it goes over cold land and
the reactions slow down due to the lack of heat, because the cool air over
the cool ground cannot hold the water vapor as well, fog is formed (close
to ground) or clouds are formed (in air)
Because we are TRAPPING the LONG waves, we are TRAPPING energy, and
therefore weather systems are more violent, stronger hurricanes, more
tornadoes, stronger winds
oThe earth is trying to create an Equilibrium, so therefore it is trying to mix it
around because more is trapped in the atmosphere when it should have
been released
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Baumgartner reached an altitude of 39km with an estimated speed of. Realistically, we call up to 500km off the surface part of our atmosphere because up to 10,000 is so few and far between particles or molecules. Atmospheric composition: heterosphere layers of gasses hydrogen, helium, oxygen, Atmospheric temperature each layer has different temperature see chart in prezi: thermosphere, mesoshere. Fewer collisions between the molecules so therefore there is very little heat: stratoshere. Fewer collisions between the molecules so therefore there is very little heat: troposhere where we live, holds in heat, has a mixture of gasses. Goes up and we hit the troposphere, which differentiates the two from the stratosphere. Because there are more molecules in the air here, more heat is generated by molecules crashing together. If we don"t have enough ozone, too much uv rays get to the surface. It has detrimental effects on humans skin cancer.
