Hi,
In order of your questions I've found these site which describe your
answers for you in detail.
Notes: The Earth's Heat Budjet
http://www.sfos.uaf.edu/msl111/notes/heat.html
2; Properties of the atmosphere are partially determined by its
stability, or resistance to change. Change in air temperature relative
to altitude is a major factor in predicting atmospheric stability.
From the earth's surface to around 36,000 feet, the temperature
decreases with altitude. This occurs because the atmosphere is heated
by conduction from the warm earth. Incoming solar radiation is
absorbed by and heats up the earth, which in turn warms the adjacent
atmosphere. The farther one travels from the warm earth, the colder
the air becomes. The temperature decrease that occurs as altitude
increases is known as the lapse rate. In standard conditions, the
lapse rate is about 3.5ƒF for every 1,000 feet. The actual lapse rate
varies from day to day. When the temperature decreases rapidly with
increased altitude, the actual lapse rate is high and the atmosphere
unstable. Conversely, a stable atmosphere reflects a low lapse rate.
Embry Riddle -Atmospheric Stability
http://www.erau.edu/0Universe/05/articles/cont18.html
3;
Atmospheric motion is driven by the uneven distribution of solar
energy
Water Cycle Lecture Text
http://www.geology.sdsu.edu/classes/geol351/01watercycle/watercyclelect.htm
4;
The theory of plate tectonics states that the earth’s surface has a
number of rigid, brittle segments that move around. The outlines of
these plates are easy to see on a world map of earthquakes.
Earthquakes occur where brittle pieces of the earth are slipping past
one another. When you break a dish, a "crack" occurs and there is a
separation of two or more pieces. The noise is analogous to the
earthquake and the crack is where relative motion between two pieces
takes place. The plate is called of “Lithosphere”. Within the
lithosphere is the crust and upper portion of the mantle. There are
three kinds of boundaries between plates.
The potential causes of Earth expansion were investigated by Maxlow
(1995) and extensively reviewed by Egyed (1963), Wesson (1973) and
Carey (1983a). Five main themes were considered, including:
1. A pulsating Earthwhere cyclic expansion of the Earth opened the
oceans and contractions caused orogenesis (eg. Khain, 1974; Steiner,
1967, 1977; Milanovsky, 1980; Smirnoff, 1992; Wezel, 1992). This
proposal failed to satisfy exponentially waxing expansion. Carey
(1983a) considered the theme to have arisen from a misconception that
orogenesis implies crustal contraction and saw no compelling evidence
for intermittent contractions.
2. Meteoric and asteroidal accretion(eg. Shields, 1983a, 1988;
Dachille, 1977, 1983; Glikson, 1993). This was rejected by Carey
(1983a) as the primary cause of Earth expansion since expansion should
then decrease exponentially with time. It also does not explain ocean
floor spreading.
3. A constant Earth masswith phase changes of an originally
super-dense core: (eg. Lindemann, 1927; Egyed, 1956; Holmes, 1965;
Kremp, 1983). Carey (1983a) rejected this because he considered the
theme to imply too large a surface gravity throughout the Precambrian
and Palaeozoic.
4. A secular reduction of the universal gravitation constant, G(eg.
Ivanenko & Sagitov, 1961; Dicke, 1962; Jordan, 1969; Crossley &
Stevens, 1976; Hora, 1983). Such a decline of G was considered to
cause expansion through release of elastic compression energy
throughout the Earth and phase changes to lower densities in all
shells. Carey (1983a) again rejected this proposal as the main cause
of expansion for three reasons: a) that surface gravity would have
been unacceptably high; b) that the magnitude of expansion would
probably be too small and; c) the arguments for a reduction in G were
considered not to indicate an exponential rate of increase.
5. A cosmological cause involving a secular increase in the mass of
the Earth (eg. Hilgenberg, 1933; Kirillov, 1958; Blinov, 1973, 1983;
Wesson, 1973; Carey, 1976; Neiman, 1984, 1990; Ivankin, 1990). Carey
(1983a) considered that the first four proposals for cause of Earth
expansion are soundly based and may have contributed in part to Earth
expansion.
http://jennifer.lis.curtin.edu.au/theses/available/adt-WCU20020117.145715/unrestricted/02Chapter1.pdf
Thanks,
webadept-ga |
Clarification of Answer by
webadept-ga
on
29 Dec 2002 13:03 PST
I've never seen a webpage act like this, it's very bizarre. I left my
browser running on my laptop when I tried to find that page in google
cache before. Now, I come back in here a couple hours later and find
the page on the screen, but I can't save it, print it or even view the
source. Very odd. We'll call it bad gnomes.
Anyway, I got the info off the page and I'm going to post it here for
you. This is from the original page I found which I felt had a better
list of information for your question.
1. Why is the Earth's heat budget important?
The heat budget describes what happens to the sun's radiation (heat,
light) that is received by the Earth.
The balance between the energy that the Earth receives and the energy
that is lost from the Earth to space maintains the Earth's constant
average temperature.
The energy from the sun drives the circulation of the atmosphere and
ocean: winds, ocean surface currents, and thermohaline circulation.
The sun's energy, and the response of the atmosphere and land to
heating by the sun, are responsible for the Earth's weather and
climate.
2. The amount of radiation the Earth's surface receives varies with
latitude and with season.
When averaged over the year, the Earth's surface receives more energy
at the equator (about 1.6 calories/cm2 minute) than at the poles
(about 0.5 calories/cm2 minute).
This is because the sun's rays strike the Earth at an angle, except at
the Equator.
The energy must also travel a greater distance through the atmosphere
at higher latitudes, causing more energy to be absorbed before it
strikes the Earth's surface.
Because the Earth's axis of rotation is tilted, rather than
perpendicular, with respect to the Earth-sun plane, the northern
hemisphere receives more radiation in April-September, while the
southern hemisphere receives more during October-March.
3. Of the energy received by the top of the Earth's atmosphere, on
average:
31% is reflected back into space by the atmosphere (mainly by clouds)
before reaching the Earth's surface.
4% is reflected by the Earth's surface back into space.
59.5% is reradiated from the Earth's atmosphere back into space.
5.5% is reradiated from the Earth's surface back into space.
Notice that the total of these numbers is 100%. This means that the
Earth's heat budget is balanced, and that (on average) the Earth is
not getting warmer or colder. (Except that a very slow warming due to
the "greenhouse effect" of anthropogenic carbon dioxide is probably
occurring.)
Reflection occurs when the sun's light "bounces" off a surface without
a substantial change in the wavelength of the radiation.
Reradiation occurs when the sunlight is absorbed by a material,
heating it. If the surroundings are colder than this material, it will
lose the heat in a process called radiation.
59.5% of the incoming solar radiation is lost as reradiation from the
atmosphere. The atmosphere's heat comes from:
42% transferred from the Earth's surface,
29.5% by evaporation (the latent heat of vaporization is released to
the atmosphere when the water condenses)
12.5% by conduction (direct heat transfer)
17.5% of the incoming solar energy absorbed directly by the
atmosphere.
4. Different parts of the Earth's surface respond differently to the
sun's energy.
Snow reflects much of the light it receives.
Vegetation, and especially dark soil and rock, tend to absorb most of
the radiation. These land surfaces have low heat capacity; there is a
large temperature change for a relatively small energy input.
The sea surface absorbs much of the energy it receives (but reflection
increases if the sun's rays are not perpendicular to the surface).
Water has a high heat capacity.
5. The amount of the reradiated heat from the Earth's surface that is
absorbed by the atmosphere depends mostly on the concentration of
"greenhouse gases".
The main greenhouse gases are carbon dioxide and water vapor.
Greenhouse gases are essential to the Earth's climate; without
approximately 300 parts per million (ppm) of carbon dioxide in our
atmosphere, the average Earth temperature would be about -20° C.
However, burning of fossil fuels has been increasing the carbon
dioxide content of the atmosphere, from about 280 ppm before the
Industrial Revolution to about 360 ppm now.
Continuing use of fossil fuels is likely to result in a carbon dioxide
concentration of 600 ppm by 2050.
This alone would be expected to cause a significant warming of the
Earth's climate, 2-4° C, with greater warming at high latitudes.
But, controls on the Earth's climate are complex. Climate predictions
must consider:
Potential increases in cloud cover with increased temperature.
Effects of sulfur aerosol (fine droplets of sulfuric acid and related
substances) which tends to increase cloud cover. Sulfur aerosol comes
mainly from burning of sulfur-containing coal.
The geologic record contains evidence of massive shifts in Earth's
climate, associated with only small (or no) changes in atmospheric
carbon dioxide. Other factors, including changes in ocean circulation,
are important.
Therefore, scientists still cannot predict accurately what the effects
of anthropogenic carbon dioxide will be.
Hope that helps and thanks again,
webadept-ga
|
