Transcript Hot air acts like a lid on the atmosphere

the state of the
atmosphere at a
given time and place
observations of
weather over a long
period of time
•A thick blanket of gases
surrounding the Earth
•composed of AIR (a mixture
of gases)
Nitrogen (N)
78%
Oxygen (O)
21%
Also, H2O Vapor, Carbon Dioxide
(CO2), and Argon (Ar) in small
amounts
the source of all clouds and
precipitation
The
atmosphere
rapidly thins
as you travel
away from
Earth until
there are
too few gas
molecules to
detect.
What are the layers
of the atmosphere?
• Troposphere:layer of the atmosphere
closest to the Earth- temperature
decreases with an increase in altitude
where weather happens
• Stratosphere: second layer of the
atmosphere- temperature remains constant
to a height of about 20 kilometers
where the ozone layer is
where airplanes fly
Mesosphere: third layer of the
atmosphere- decreasing
temperatures with height
where meteors burn up
Thermosphere: outmost layer of
the atmosphere- increasing
temperatures due to the
absorption of very short-wave
solar energy by oxygen
where auroras happen
Auroras/Northern Lights
3 oxygen atoms
bonded together
O is an atom of Oxygen (O)
O2 is atmospheric Oxygen (O-O)
O3 is ozone (O-O-O)
•Absorbs 99% of harmful
ultraviolet rays from the sun
•ozone layer is about 10 to 20 km
thick (found in the stratosphere)
•thinning is the result of
chloroflorocarbons (CFC’s)
containing chlorine, fluorine, and
carbon
One chlorine atom can destroy 10,000
ozone molecules!
This shows a hole in the ozone
What is radiant energy?
Almost all of the Earth’s energy
comes from the sun and is called
radiant energy
•most reaches
the atmosphere
and is reflected
back to space
•Some is absorbed by the Earth and
is spread throughout the
atmosphere as:
•Radiation: transfer of energy in
form of waves
Energy travels from the sun to the earth by means of electromagnetic
waves. The shorter the wavelength, the higher the energy associated with
it. This is demonstrated in the animation below. As the drill's revolutions
per minute (RPMs) increase, the number of waves generated on the string
increases, as does the oscillation rate. The same principle applies to
electromagnetic waves from the sun, where shorter wavelength radiation
has higher energy than longer wavelength radiation.
What is conduction? direct
transfer of energy from one
substance to another
What is convection? transfer of
energy in a fluid
•air is a fluid- hot air rises, cool
air sinks
As much energy leaves the
Earth that comes in ---> Earth’s
heat is balanced.
What is the greenhouse effect?
trapping of the sun’s energy by
the Earth
•caused by the burning of
fossil fuels- coal, oil, and
natural gas- adds CO2 into air
•warming effect may melt
glaciers and raise sea levels
Hot air acts like a lid on the atmosphere
During the heat of summer, a layer of hot air in which
the temperature increases with height often forms
high above the Earth. The layer of hot air prevents
polluted air near the surface from mixing with
cleaner air above it. To make matters worse, the heat
helps trap pollution from automobile exhaust and
factory emissions.
Houston on a smoggy day (left) and a clear
day (right).
Greenhouse gases trap heat like a blanket, causing the Earth’s atmosphere to warm. Carbon dioxide (CO2)
released from the burning of coal and other fossil fuels is the predominant greenhouse gas, although methane
emissions from agriculture are estimated to be 21 times more effective at trapping heat than CO2. In North
Carolina, CO2 emissions have grown steadily along with increases in energy consumption, with emissions of
CO2 increasing by more than 30% since 1990. North Carolina’s residential energy consumption is expected to
increase by about 50% by 2020. [Source: Understanding Climate Change for North Carolina]
From website http://www.2think.org/keeling_curve.shtml
What are pollutants?
Air pollutants: airborne particles and
gases that occur in concentrations
large enough to endanger the
environment
•primary pollutants: emitted directly
from an identifiable source
transportation
vehicles account
for nearly half!
•secondary pollutants: form in the
atmosphere where reactions take
place among primary pollutants and
other substances
Emissions from transportation vehicles
account for nearly half the primary
pollutants by weight.
How environmentally safe is your car?
Air Pollution from
Coal-burning Power Plants
Acid rain
SO2
Visibility degradation
Fine particulates
NOX
Ground level ozone
Fine particle pollution
Acid rain
Visibility degradation
What is the Clean Air Act?
• Passed in 1970 and strengthened
in 1990
• Gives the Environmental
Protection Agency the authority
to regulate automobile emissions
• Eliminated lead gas
Once a thick tongue of ice that poured into the Gletsch valley (inset), the Rhone
Glacier has shrunk dramatically since 1850. In 2003, the Rhone Glacier and other
Swiss glaciers retreated more than any other year since scientists began taking
measurements in the 1800s. While the summer’s extreme temperatures caused the
glaciers to thin more than usual, scientists say that the glaciers retreated in
response to long-term warming.
Vostok Ice Core Record - 4 Glacial Cycles
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Source: Petit et al., 1999, Nature 399, p. 429-346.
Burning Fossil Fuels
Air Pollution
Greenhouse Gas
Emissions
Climate Change
Asthma Attacks
Other Respiratory Illnesses
Premature Death from Lung
and Heart Diseases
Heat-Related Deaths
Infectious Diseases
Injuries from Extreme
Weather Events
Allergies
Potential Climate Change Impacts
Health Impacts
Weathe r-relate d Mortality
Infectious Diseases
Air Quality-Respiratory Illnesses
Agriculture Impacts
Climate Changes
Temperature
Precipitation
Sea Level Rise
Crop yields
Irrigation dem ands
Forest Impacts
Change in fore st composition
Shif t geographic ra ngeof forests
Forest He alth and Productivity
Water Resource Impacts
Change s in water supply
Water quality
Increased competion for water
Impacts on Coastal Areas
Erosion of beac hes
Inundate coastal lands
Costs to de fend coa stal communities
Species and Natural Areas
Shif t in ecological zones
Loss of habitat and species
•average kinetic energy of the
atoms or molecules in a particular
substance
•the more energy the molecules
have, the hotter it feels
the energy transferred from
one object to another
because of a difference in
their temperatures
What are isotherms? lines on a map
that connect places that have the
same temperature
What is a thermometer?
instrument that measures
temperature
•alcohol and mercury
thermometers used (mercury
more accurate)
water freezes at: 0ºC or 32 ºF
water boils at: 100ºC or 212ºF
Why does temperature vary?
 Land and Water
• Land heats more rapidly and to higher
temperatures than water. Land also cools
more rapidly and to lower temperatures
than water.
Mean Monthly Temperatures
for Vancouver and Winnipeg
Why Temperatures Vary
 Geographic
•
Position
The geographic setting can
greatly influence temperatures
experienced at a specific
location.
Mean Monthly Temperatures for
Eureka and New York City
Mean Monthly Temperatures
for Seattle and Spokane
Why Temperatures Vary
 Altitude
• The altitude can greatly influence
temperatures experienced at a
specific location.
Mean Monthly Temperatures for Guayaquil
and Quito