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#Post#: 376--------------------------------------------------
Tugasan 5 KN
By: riskzal Date: March 1, 2011, 10:26 pm
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sila dapatkan maklumat tambahan mengenai :
1. Greenhouse effect
2. Ozone layer
hantar di sini. harap maklum
#Post#: 377--------------------------------------------------
Re: Tugasan 5 KN
By: syedmohdnaufal 5kn Date: March 1, 2011, 10:34 pm
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1)Greenhouse effect : The greenhouse effect is a process by
which thermal radiation from a planetary surface is absorbed by
atmospheric greenhouse gases, and is re-radiated in all
directions. Since part of this re-radiation is back towards the
surface, energy is transferred to the surface and the lower
atmosphere. As a result, the temperature there is higher than it
would be if direct heating by solar radiation were the only
warming mechanism.[1][2]
This mechanism is fundamentally different from that of an actual
greenhouse, which works by isolating warm air inside the
structure so that heat is not lost by convection.
The greenhouse effect was discovered by Joseph Fourier in 1824,
first reliably experimented on by John Tyndall in 1858, and
first reported quantitatively by Svante Arrhenius in 1896.[3]
If an ideal thermally conductive blackbody was the same distance
from the Sun as the Earth is, it would have a temperature of
about 5.3 °C. However, since the Earth reflects about 30%[4] (or
28%[5]) of the incoming sunlight, the planet's effective
temperature (the temperature of a blackbody that would emit the
same amount of radiation) is about −18 or −19
°C,[6][7] about 33°C below the actual surface temperature of
about 14 °C or 15 °C.[8] The mechanism that produces this
difference between the actual surface temperature and the
effective temperature is due to the atmosphere and is known as
the greenhouse effect.
Global warming, a recent warming of the Earth's surface and
lower atmosphere,[9] is believed to be the result of a
strengthening of the greenhouse effect mostly due to
human-produced increases in
attmospheric greenhouse gases.[10
2) Ozone Layer : The ozone layer is a layer in Earth's
atmosphere which contains relatively high concentrations of
ozone (O3). This layer absorbs 97–99% of the Sun's high
frequency ultraviolet light, which is damaging to life on
Earth.[1] It is mainly located in the lower portion of the
stratosphere from approximately 13 to 40 kilometres (8.1 to 25
mi) above Earth, though the thickness varies seasonally and
geographically.[2] The ozone layer was discovered in 1913 by the
French physicists Charles Fabry and Henri Buisson. Its
properties were explored in detail by the British meteorologist
G. M. B. Dobson, who developed a simple spectrophotometer (the
Dobsonmeter) that could be used to measure stratospheric ozone
from the ground. Between 1928 and 1958 Dobson established a
worldwide network of ozone monitoring stations, which continue
to operate to this day. The "Dobson unit", a convenient measure
of the columnar density of ozone overhead, is named in his
honor.
Syed naufal , Naim hamzi dan Hafizhat
#Post#: 378--------------------------------------------------
Re: Tugasan 5 KN
By: zHaf 4kn Date: March 1, 2011, 10:35 pm
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HTML http://en.wikipedia.org/wiki/Greenhouse_effect
::) ;D
#Post#: 379--------------------------------------------------
Re: Tugasan 5 KN
By: Fauzi 4KN Date: March 1, 2011, 10:37 pm
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Greenhouse Effect ! ;D
From Wikipedia, the free encyclopedia
Jump to: navigation, search
A representation of the exchanges of energy between the source
(the Sun), the Earth's surface, the Earth's atmosphere, and the
ultimate sink outer space. The ability of the atmosphere to
capture and recycle energy emitted by the Earth surface is the
defining characteristic of the greenhouse effect. Wikimedia
Commons has media related to: Greenhouse effect
Look up greenhouse effect in Wiktionary, the free dictionary.
Wikibooks has a book on the topic of
Climate Change
Wikiversity has learning materials about Topic:Climate change
The greenhouse effect is a process by which thermal radiation
from a planetary surface is absorbed by atmospheric greenhouse
gases, and is re-radiated in all directions. Since part of this
re-radiation is back towards the surface, energy is transferred
to the surface and the lower atmosphere. As a result, the
temperature there is higher than it would be if direct heating
by solar radiation were the only warming mechanism.[1][2]
This mechanism is fundamentally different from that of an actual
greenhouse, which works by isolating warm air inside the
structure so that heat is not lost by convection.
The greenhouse effect was discovered by Joseph Fourier in 1824,
first reliably experimented on by John Tyndall in 1858, and
first reported quantitatively by Svante Arrhenius in 1896.[3]
If an ideal thermally conductive blackbody was the same distance
from the Sun as the Earth is, it would have a temperature of
about 5.3 °C. However, since the Earth reflects about 30%[4] (or
28%[5]) of the incoming sunlight, the planet's effective
temperature (the temperature of a blackbody that would emit the
same amount of radiation) is about −18 or −19
°C,[6][7] about 33°C below the actual surface temperature of
about 14 °C or 15 °C.[8] The mechanism that produces this
difference between the actual surface temperature and the
effective temperature is due to the atmosphere and is known as
the greenhouse effect.
Global warming, a recent warming of the Earth's surface and
lower atmosphere,[9] is believed to be the result of a
strengthening of the greenhouse effect mostly due to
human-produced increases in atmospheric greenhouse gases.[10]
Ozone Layer ! ;D
From Wikipedia, the free encyclopedia
Jump to: navigation, search
The ozone layer is a layer in Earth's atmosphere which contains
relatively high concentrations of ozone (O3). This layer absorbs
97–99% of the Sun's high frequency ultraviolet light, which is
damaging to life on Earth.[1] It is mainly located in the lower
portion of the stratosphere from approximately 13 to 40
kilometres (8.1 to 25 mi) above Earth, though the thickness
varies seasonally and geographically.[2] The ozone layer was
discovered in 1913 by the French physicists Charles Fabry and
Henri Buisson. Its properties were explored in detail by the
British meteorologist G. M. B. Dobson, who developed a simple
spectrophotometer (the Dobsonmeter) that could be used to
measure stratospheric ozone from the ground. Between 1928 and
1958 Dobson established a worldwide network of ozone monitoring
stations, which continue to operate to this day. The "Dobson
unit", a convenient measure of the columnar density of ozone
overhead, is named in his honor.
#Post#: 380--------------------------------------------------
Re: Tugasan 5 KN
By: zHaf 4kn Date: March 1, 2011, 10:38 pm
---------------------------------------------------------
HTML http://en.wikipedia.org/wiki/Ozone_depletion
;D ;D ;D ;D ;D
#Post#: 381--------------------------------------------------
Re: Tugasan 5 KN
By: hafizhamid Date: March 1, 2011, 10:39 pm
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HTML http://en.wikipedia.org/wiki/Greenhouse_effect
#Post#: 382--------------------------------------------------
Re: Tugasan 5 KN
By: MOHD HISYAM Date: March 1, 2011, 10:42 pm
---------------------------------------------------------
The greenhouse effect is a process by which thermal radiation
from a planetary surface is absorbed by atmospheric greenhouse
gases, and is re-radiated in all directions. Since part of this
re-radiation is back towards the surface, energy is transferred
to the surface and the lower atmosphere. As a result, the
temperature there is higher than it would be if direct heating
by solar radiation were the only warming mechanism.[1][2]
This mechanism is fundamentally different from that of an actual
greenhouse, which works by isolating warm air inside the
structure so that heat is not lost by convection.
The greenhouse effect was discovered by Joseph Fourier in 1824,
first reliably experimented on by John Tyndall in 1858, and
first reported quantitatively by Svante Arrhenius in 1896.[3]
If an ideal thermally conductive blackbody was the same distance
from the Sun as the Earth is, it would have a temperature of
about 5.3 °C. However, since the Earth reflects about 30%[4] (or
28%[5]) of the incoming sunlight, the planet's effective
temperature (the temperature of a blackbody that would emit the
same amount of radiation) is about −18 or −19
°C,[6][7] about 33°C below the actual surface temperature of
about 14 °C or 15 °C.[8] The mechanism that produces this
difference between the actual surface temperature and the
effective temperature is due to the atmosphere and is known as
the greenhouse effect.
Global warming, a recent warming of the Earth's surface and
lower atmosphere,[9] is believed to be the result of a
strengthening of the greenhouse effect mostly due to
human-produced increases in atmospheric greenhouse gases.[10]
#Post#: 383--------------------------------------------------
Re: Tugasan 5 KN
By: amirul 4kn Date: March 1, 2011, 10:44 pm
---------------------------------------------------------
The "greenhouse effect" often gets a bad rap because of its
association with global warming, but the truth is we couldn't
live without it.
What Causes the Greenhouse Effect?
Life on earth depends on energy from the sun. About 30 percent
of the sunlight that beams toward Earth is deflected by the
outer atmosphere and scattered back into space. The rest reaches
the planet's surface and is reflected upward again as a type of
slow-moving energy called infrared radiation.
The heat caused by infrared radiation is absorbed by "greenhouse
gases" such as water vapor, carbon dioxide, ozone and methane,
which slows its escape from the atmosphere.
Although greenhouse gases make up only about 1 percent of the
Earth's atmosphere, they regulate our climate by trapping heat
and holding it in a kind of warm-air blanket that surrounds the
planet.
This phenomenon is what scientists call the "greenhouse effect."
Without it, scientists estimate that the average temperature on
Earth would be colder by approximately 30 degrees Celsius (54
degrees Fahrenheit), far too cold to sustain our current
ecosystem.
#Post#: 385--------------------------------------------------
Re: Tugasan 5 KN
By: MOHD HISYAM Date: March 1, 2011, 10:45 pm
---------------------------------------------------------
The ozone layer is a layer in Earth's atmosphere which contains
relatively high concentrations of ozone (O3). This layer absorbs
97–99% of the Sun's high frequency ultraviolet light, which is
damaging to life on Earth.[1] It is mainly located in the lower
portion of the stratosphere from approximately 13 to 40
kilometres (8.1 to 25 mi) above Earth, though the thickness
varies seasonally and geographically.[2] The ozone layer was
discovered in 1913 by the French physicists Charles Fabry and
Henri Buisson. Its properties were explored in detail by the
British meteorologist G. M. B. Dobson, who developed a simple
spectrophotometer (the Dobsonmeter) that could be used to
measure stratospheric ozone from the ground. Between 1928 and
1958 Dobson established a worldwide network of ozone monitoring
stations, which continue to operate to this day. The "Dobson
unit", a convenient measure of the columnar density of ozone
overhead, is named in his honor.
#Post#: 386--------------------------------------------------
Re: Tugasan 5 KN
By: zHaf 4kn Date: March 1, 2011, 10:45 pm
---------------------------------------------------------
How Do Humans Contribute to the Greenhouse Effect?
While the greenhouse effect is an essential environmental
prerequisite for life on Earth, there really can be too much of
a good thing.
The problems begin when human activities distort and accelerate
the natural process by creating more greenhouse gases in the
atmosphere than are necessary to warm the planet to an ideal
temperature.
Burning natural gas, coal and oil -including gasoline for
automobile engines-raises the level of carbon dioxide in the
atmosphere.
Some farming practices and land-use changes increase the levels
of methane and nitrous oxide.
Many factories produce long-lasting industrial gases that do not
occur naturally, yet contribute significantly to the enhanced
greenhouse effect and "global warming" that is currently under
way.
Deforestation also contributes to global warming. Trees use
carbon dioxide and give off oxygen in its place, which helps to
create the optimal balance of gases in the atmosphere. As more
forests are logged for timber or cut down to make way for
farming, however, there are fewer trees to perform this critical
function.
Population growth is another factor in global warming, because
as more people use fossil fuels for heat, transportation and
manufacturing the level of greenhouse gases continues to
increase. As more farming occurs to feed millions of new people,
more greenhouse gases enter the atmosphere.
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