PHY 113 Lecture Notes - Lecture 7: Solar Wind, Continental Drift, Seismic Wave
9 Jun 2018
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Chapter 7 Earth
7.1 Overall Structure of Planet Earth
7.2 Earth‚ Atmosphere Why Is the Sky Blue?
The Greenhouse Effect and Global Warming
7.3 Earth‚ Interior Radioactive Dating
7.4 Surface Activity
7.5 Earth‚ Magnetosphere 7.6 The Tides
7.1 Overall Structure of Planet Earth
We sometimes think of the atmosphere as being very thick (after all it goes up for miles!)
This video helps us keep it in perspective!
http://www.youtube.com/watch? v=Ip2ZGND1I9Q
This universal sense of awe should properly
be re-directed from creation to Creator.
7.2 Earth‚ Atmosphere
The blue curve shows the temperature at each altitude
Troposphere is where convection takes place— responsible for weather
Convection depends on warming of ground by the Sun
Ionosphere is ionized by solar radiation and is good conductor
Reflects radio waves in the AM range, but transparent to FM and TV
Ozone layer is between ionosphere and mesosphere; absorbs ultraviolet radiation
Chlorofluorocarbons
(CFCs) have been damaging the ozone layer, resulting in ozone hole
Sunlight that is not reflected is absorbed by Earth‚ surface, warming it
Surface re-radiates as infrared thermal radiation
Atmosphere absorbs some infrared, causing further heating
This is known as the
greenhouse effect
More Precisely 7-1: Why Is the Sky Blue?
Scattering of light by air depends on the wavelength of the light— the wavelength of blue
light is closer to the size of air molecules, so it is scattered most strongly.
The amount of scattering is proportional to the inverse fourth power of the wavelength.
This is the same reason sunset and sunrise looks orange/red.
The blue light is scattered!
7.2 Earth‚ Atmosphere History of Earth‚ atmosphere:
Primary atmosphere was hydrogen, helium; most of this escaped Earth‚ gravity
Secondary atmosphere, from volcanic activity, mostly nitrogen
Life appeared, creating atmospheric oxygen
Discovery 7-1: The Greenhouse Effect and Global Warming
One result of modern society has been to increase CO2 levels in the atmosphere.
Acorresponding increase in global average temperature has been seen as well. Exactly how
much the temperature will continue to increase is not known.
Some possible consequences of global warming:
Rise in sea level
More severe weather
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
We sometimes think of the atmosphere as being very thick (after all it goes up for miles!) This video helps us keep it in perspective! http://www. youtube. com/watch? v=ip2zgnd1i9q. This universal sense of awe should properly be re-directed from creation to creator. The blue curve shows the temperature at each altitude. Troposphere is where convection takes place responsible for weather. Convection depends on warming of ground by the sun. Ionosphere is ionized by solar radiation and is good conductor. Reflects radio waves in the am range, but transparent to fm and tv. Ozone layer is between ionosphere and mesosphere; absorbs ultraviolet radiation. Chlorofluorocarbons (cfcs) have been damaging the ozone layer, resulting in ozone hole. Sunlight that is not reflected is absorbed by earth surface, warming it. Scattering of light by air depends on the wavelength of the light the wavelength of blue light is closer to the size of air molecules, so it is scattered most strongly.
