Figure 15.1 Trend in the departure of surface temperature over the last 120 years.
Notice the trend of increasing temperature over the last two decades.
Figure 15.2. The earth does not circle the sun in a perfect circle, but rather as an
ellipse. Eccentricity defines the shape of the Earth's orbit around the sun. This change
in shape of the orbit, represented by the solid and dashed lines, occurs in a cycle lasting
approximately 100,000 years, and is one cycle in the Milankovitch cycle.
Titl angle varies from
22.1 to 24.5 degrees
Figure 15.3 The tilt of the Earth axis varies from 22.1 to 24.5 degrees off the
perpendicular with a cycle that lasts 41,000 years.
(Replace earth
with a top)
Figure 15.4. Earth wobbles on its axis making in a period of about 23,000 years. In
approximate 11,000 years the Northern Hemisphere will be titled away form the sun in
June, causing the Northern Hemisphere summer to occur in January! (Ahrens
Hardcover has a nice figure, Fig. 19.10, p. 514.)
Fall Equinox
Sept 22
Dec 22
Winter
Solstice
Jan 3
94 days of summer
90 days
of fall
89 days of
winter
93 days
of spring
July 4
Summer
Solstice
Summer Equinox
June 22
March 21
June 18
Summer
Solstice
Summer Equinox
89 days
of spring
89 days
of summer
June 27
Fall Equinox
March 21
94 days of winter
93 days
of fall
Dec 26
Winter
Solstice
Dec17
Sept 15
Figure 15.5. The shift of the position of the equinoxes and solstices from today (top)
and for11,000 years ago (bottom). The times of perihelion (Earth closest to the sun) and
aphelion (furthest from the sun) are also shown. The summer solstice of the Northern
Hemisphere occurred closer to perihelion 11,000 years ago than it does today. (The shape
of this diagram is exaggerated for clarity).
Figure 15.6. Variations in the amount of the sun's energy reaching the earth closely
matches the global average temperatures over the last 800,000 years. (I'm working on
this one)
Decrease in surface
temperature
reduced amount
of solar radiation
reduces energy
gains
Increased area
of ice, increase
planetary albedo
Figure 15.7 Ice-albedo-temperature feedback represent how a small change can
feedback on itself to enhance a change. (Can enhance this with figures of ice
thermometers and sun. Or use little figures of the earth with different amounts of
ice and solar energy being reflected out to space.)
Figure 15.8 Most aerosol are generated by natural processes. Natural primary aerosols
include soil dust, sea salt, biological debris, and volcanic debris. Anthropogenic primary
sources of aerosol include industrial pollution, soot from fossil fuel combustion, and soot
from biomass burning. Secondary aerosols form as a result of chemical reactions in the
atmosphere.
Figure 15.9 Large aerosol concentrations associated with dust storms can obscure
the sky. Such concentrations of the dust; can be hazardous have been known to suffocate
cattle left unprotected. A menacing sandstorm approaching Big Spring, TX on 14
September 1930. This storm was a forerunner of the Dust Bowl years. In: "Monthly
Weather Review," January 1931, p. 30. NOAA photo archive.
Figure 15.10 A view of Tambora from the Space Shuttle (Photo STS047-0071-0083).
The 1815 eruption of Tambora was the largest eruption in historic time. The eruption
column reached a height of about 28 miles (44 km) formed a caldera, as seen in this
photograph.
Figure 15.11. The eruption of Mt Pinatubo produced a stratospheric aerosol that
resulted in a global cooling of approximately 0.6C. (Photos courtesy of USGS Cascades
Volcano Observatory.
http://volcano.und.nodak.edu/vwdocs/volc_images/southeast_asia/pinatubo.html)
Global Temperature Departures from 1951-1980 mean
Temperature Departure (  C)
1
0.5
0
Eruption of Mt Pinatubo
-0.5
1970
1975
1980
1985
1990
1995
2000
Year
Figure 15.12 Global temperature departures from the 1951-1980 global average
temperature (approximately 14C = 57.2F). The eruption caused a global cooling of up to
0.3 C by July 1992. (Multiply C departure by 1.8(=9/5) to get changes in degrees
Fahrenheit. Add 0 line.)
Figure 15.13 The pH level of rain over North America measured in 1982. Purple
shaded regions indicate acid rain regions.
Figure 15.14 Measurements of trace gases in polar regions away from industrial areas
are a good indication of how human activities are affecting the concentrations of
greenhouse gases over the last 150 years. (Drop dots and dotted line on bottom figure,
and eliminates N2O curve, and drop "in situ". )
Figure 15.15 This is a visible image from a geostationary satellite of stratus clouds off
the coast of California. The ragged lines in the upper potions of the figure are clouds
whose reflectance has been enhance due to increased aerosol from ships moving below
the clouds. This suggests that human activities may increase the brightness of clouds,
and thereby cause a cooling of the planet. (May want to point to the shiptracks to
make them obvious, they are the wavey lines.)
Figure 15.16 Observations of monthly averaged ozone concentrations over Halley Bay
in Antarctic. indicate a decreasing trend in total ozone amounts since 1955.
Figure 15.17 October monthly mean ozone amounts over the Antarctic during the
periods 1980-1991 as measured by NASA satellites.
Figure 15.18. A simplified view of today's ocean circulation. Shown are the warm
surface currents, the cold deep currents. The red dots (change color) represent areas
where deep water is formed. Changes in these currents can bring about regional and
global climate changes. (I go this figure from Segar's Ocean Sciences. WE might
want to highlight that discussed in thetext.)
Figure 15.19 A combination of drought during 1926-1934 and poor soil
conservation practices resulted in severe wind erosion in the shaded regions. Millions of
hectares of farmland went to waste during the Dust Bowl. The ecological disaster forced
hundreds of thousands of people to leave their homes to find work in cities and farms
elsewhere, as dust storms buried farms and equipment in soil, killed livestock as well as
people. (Photo from NOAA archives, bottom photo also in: "Monthly Weather Review,"
June 1936, p.196.) (Photo credit: NOAA) (Can we combine the graphic with the
photographs?)
Figure 15.20 The average summertime temperature and rainfall of Topeka, Kansas for
the 100 year period between 1890 and 1990. The Dust Bowl occurred in the mid-1930s.
(Separate temperature and precipitation in above figure taken from a NOAA
document..
Figure 15.21 Shelterbelts reduce the wind speed downwind and keep the wind from
lifting the soil and transporting away from the farmland. (Just plot loose, or solid, curve,
replace line labeled Belt 1 with trees.)
Rural regions
have larger
evaportranspiration
rates and open space reflect
solar engery ot to space.
Cities have less
evapotranspiration
and the
buildings trap
solar radiation.
Figure 15.22 Concrete roadways and building reduce evapotranspiration and absorb
more solar radiation than surround rural regions. As a result, urban areas are often
warmer.
Figure 15.23 Average winter low temperatures (F) in the Washington DC and
surrounding area. The city, denoted by the dark region, is generally warmer than the
surrounding area. (Simplify figure, this one is from Moran and Morgan, which got it
from Woollum article in Weatherwise 17, No. 6 1964)
Figure 15.24 A satellite image demonstrating the urban heat island. Find the following
geographic regions: Lake Erie, Lake Ontario, Long Island, Chesapeake Bay, Delaware
Bay, Hudson River, Finger Lakes, Appalachian Mountains. The city of Pittsburgh is
marked to help you recognize the heat island feature. Can you find the following urban
heat islands: Washington, New York Metropolitan Area, Philadelphia, Buffalo,
Cleveland, Albany, Harrisburg, Richmond and Syracuse.
Solar
radiation
Equations
of motions
Pressure
Gradients
Transporrt
Terrestrial
radiation
Radiation
Process
Heating or
cooling
Energy Balance
Hydrologic
Cycle
Latent heating
Evaporation
Friction
Precipitation
Sensible heating
Ocean-Land-Biosphere-Cryosphere
Figure 15.25 A simplified illustration of the atmospheric processes of a climate
model. This interactions are expressed in a climate model as a series of mathematical
expressions.
Figure 15.26 The observed and simulated global annual mean warming from 1860 to
1990. Two simulations with a GCM are shown. Both simulations include increasing
amounts of greenhouse gases, the second also includes the affects of sulphate aerosols.
Comparing these two simulations with observations gives scientists an indication of the
importance of these process in climate change.
Figure 15.26 A comparison of climate predictions by different climate models shows
a warming trend; however there is uncertainty as indicated by the differences in the
amount of warming predicted. (Drop the yellow line, the dotted line and the red line,
and use some sort of shading to demonstrate the range of the different models)
Stratosphere cools
Troposphere warms
Near surface air temperature increase
greatest at NH latitude during winter
Prccipitation in NH
high latitudes increases
Snow cover decreases
Land night-time air temperatures
rise faster than daytime temperatures
Water vapor increases
Evaporation in tropics increases
Prcipitation in NH midlatidues
during winter increase
Near surface ocean temperature increases Sea ice in NH below average
Sea ice in SH at or slightly below average
Sea levels rise
Figure 15.27 Global Climate Models agree qualitatively on several possible climate
changes that can be brought about by human activities that increase levels of atmospheric
carbon dioxide. This figure shows changes most climate models predict. (Have a figure
that, where possible, symbolically represents these processes - for example, have
little icebergs floating by the sea ice statements.)