Download Overview of the Earth`s Atmosphere

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Chapter 1: The
Earth’s Atmosphere
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Overview of the Earth’s atmosphere
Vertical structure of the atmosphere
Weather and climate
Q: You can live for a few minutes only:
a) without air
b) without water
c) without food
Overview of the
Earth’s Atmosphere
• when the earth is scaled to the size
of an apple, 99% of atmosphere is
no thicker than the skin on an apple
• Water vapor molecules are invisible:
clouds;
sink: condensation/deposition
source: evaporation/sublimation
transpiration
Fig.1.2
Composition of the
Atmosphere
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permanent gases
• Nitrogen
source: decaying of plant and animal matter
sink: soil bacteria;
ocean plankton
• Oxygen
source: plant photosynthesis (sun + CO2 + H2O
lead to sugar and O2)
sink: organic matter decay
breathing (take in O2, release CO2)
Q: which is the most important greenhouse gas in the atmosphere?
a) water vapor; b) carbon dioxide; c) methane, d) ozone
380 ppm = 380/106 = 380 * 10-4/102 = 0.038%
Table 1-1, p. 3
Composition of the
Atmosphere
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Carbon dioxide and the greenhouse gases
ozone
aerosols
pollutants
• Ozone at high altitudes
(stratosphere) is “good”;
ozone at low altitudes
(troposphere) is “bad.”
Fig. 1.4
Q: List three
sources and two
sinks of CO2 in
the atmosphere
Stepped Art
Fig. 1-3, p. 4
The Early Atmosphere
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the first atmosphere: hydrogen, helium
outgassing and the second atmosphere
water vapor, carbon dioxide, nitrogen

evolution of the atmosphere:
carbon dioxide and oxygen
• The evolution of life and the atmosphere are closely
linked.
Vertical Structure of
the Earth’s
Atmosphere
Radiosonde launched twice a
day to measure temperature,
humidity, wind, and pressure
of the lowest 30 km above
surface
Q: where is the balloon launched
in Tucson? a) airport;
b) Mt. Lemmon, c) UA campus
A Brief Look at Air Pressure
and Air Density
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air density: mass per unit volume
air pressure: air weight above a level
sea-level pressure
• Surface pressure: 1013 mb = 1013 hPa = 29.92 in.Hg
Q: Baseballs travel farther in higher-altitude air (Denver)
than they do in lower-altitude air: true or false?
Fig. 1-7, p. 8
Q: what is the
percentage of
O2 at the top
of Mt. Everest
compared with
sea level?
a) 13%
b) 23%
c) 33%
d) 43%
Fig. 1-8, p. 9
Layers of the Atmosphere

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vertical temperature profile
Troposphere
lapse rate: 6.5degC/1km;
temperature inversion

Stratosphere
O3 absorption
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mesosphere
Thermosphere
O2 absorption
The Ionosphere
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electrified regions of the atmosphere
D, E and F regions
radio waves
• When the radio was invented by G. Marconi in the
early 20th century, it was not known how radio
waves traveled long distances through the
atmosphere.
Fig. 1-11, p. 13
Weather and Climate
• Satellites
• Radar
• Radiosonde
• Aircraft
• Weather station
See ATMO web site
Elements of Weather
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air temperature
air pressure
humidity
clouds
precipitation
visibility
wind
• Certain weather elements, like
clouds, visibility and wind, are
of particular interest to pilots.
Climate


average weather
extremes
Q: What is the difference between weather and climate?
A Satellite’s View of the
Weather
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geostationary satellites
• Atmospheric observation
from satellites was an
important technological
development in
meteorology. Other
important developments
include computers, internet,
and Doppler radar.
Storms of all Sizes
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midlatitude cyclonic storms
hurricanes and tropical storms
thunderstorms
tornadoes
• Storms are very exciting, but they also play an
important role in moving heat and moisture around
throughout the atmosphere.
Fig. 1.17
Fig. 1.15
A Look at a Weather Map
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wind speed and direction
cyclones and anticyclones
fronts
• Wind direction is defined in the opposite way as
ocean currents: a southerly current means water is
moving towards the south.
Q: What is the wind direction in Chicago?
a) southerly, b) northerly, c) easterly, d) westerly
Fig. 1-13, p. 17
Weather and Climate in our
Lives
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wind chill, frostbite and hypothermia
heat exhaustion and heat stroke
cold spells, dry spells and heat waves
severe thunderstorms and flash floods
• The mathematical formula for determining the wind
chill temperature has recently been revised due to new
experiments.
Fig. 1-16, p. 19
Fig. 1.19
Fig. 1-18, p. 20