Transcript THE ATMOSPHERE - Senay's Classes

THE ATMOSPHERIC SYSTEM
The earth and its atmosphere is the greatest
natural system.
What is the input that drives this system and ?
• THE SOLAR ENERYGY!!!
The output is also the energy radiated and lost
into space.
Envelope of gases
rapped around the
earth.
The gases are
transparent and
odorless.
Gravitational pull of
the Earth keeps the
atmosphere attached
to it, though the
atmosphere itself is in
constant motion.
up to 1000 km.
30 km (97 %)
As the height increases, the atmospheric
pressure decreases.
The layers
are mainly
identified by
temperature
.
Troposphere and stratosphere are the two that
are important for us and the life on Earth.
1) Make a table, in groups, to show differences
between the troposphere and stratosphere
using these headings:
- Amount
- Temperature
- Composition
• 2)What is the tropopause?
• The troposphere is the lowest layer.
• It is warmed by conduction from the Earth’s
surface – temperature falls with increasing
height (up to -50°C).
• The tropopause is at 17000 m above the tropics
and 8000 m above the Poles.
• High percentages of water vapour and carbon
dioxide are more present than in the other
parts.
• The Earth’s cloud and weather systems are
concentrated here.
• It contains most of the atmosphere’s water
vapour, cloud, dust, and pollution.
• The stratosphere is dust-free and cloudless.
• Little carbon dioxide and water vapour are
present.
• The air is dry.
• Between 25 and 30 km is the gratest
concentration of ozone. Ozone absorbs
incoming ultaviolent (UV) radiation from the
Sun. Because of this layer, temperature is
rising in the stratosphere.
• Increasing temperature stops clouds and
weather systems from reaching this height.
Read “composition of the atmosphere” on page 119
and
1) Draw a PIE GRAPH to show the composition of dry
air.
2)Answer:
i) “Why atmospheric components present in small
quantities vary in TYPE and AMOUNT from place
to place?”
ii) “Why atmospheric components present in small
quantities have an importance greater than
their percentages would suggest?”
The percentage of carbon dioxide is tiny, but its importance
is enormous:
- it is soaked up by plants for photosynthesis.
- it absorbs long-wave heat radiation from the surface
(without carbon dioxide, the Earth would be about 30 °C
colder!)
Nitrogen and oxygen 99 %
The amount of ozone is very low, but it plays very
important role in preventing the cancer-inducing
ultraviolet rays to reach the Earth’s surface.
Amount of water vapour vary greatly from place to
place
– 0.2% by volume in deserts
- 4% in tropical areas.
Tiny particles: dust, smoke, and salt crystals.
1) Read “the Sun as an energy source” and
“insolation” sections (Pages 120,121, and 122) from
the textbook, AND give short definitions of the
keywords shown in bold in this section.
2) Explain the differences between:
a) short-wave and long-wave radiation. Which one is
more energetic? Source of production?
b) radiation, absorption and reflection of Sun's rays
3) Draw a divided BAR GRAPH to show what happens
to the 100 % of light energy radiated from the Sun.
TO REMEMBER:
- Sunlight is a short-wave radiation (Highly
energetic).
- Heat from surface causing the emission of the longwave radiation.
- Absorption (about 18 %) by the greenhouse gases:
water vapour, water droplets, and carbon dioxide
- Absorption by the Earth surface (about 50 %).
- Reflection (about 32 %)– from clouds, gases, dust
particles, light-coloured surface.
- Radiation of heat (long wavelength) happens when
a surface is heated up.
- Long wavelength radiation is less energetic than the
short wavelength radiation.
1) Read Page 121 and 122.
2) Describe how cloud cover affects surface
temperatures at night
2) Define what insolation is.
3) Explain why rates of insolation are different
between the tropical and polar latitudes.
4) A) Draw a scatter graph using the data in Table 3.2
to show the relationship between latitude (x axis)
and temperature (y axis) of the coldest month.
B) What is the main factor affecting the insolation?
C) How does this factor affect the insolation?
The long wavelength radiation from the Earth’s
surface is absorbed by water vapor and CO2. These,
in turn are heated up and radiate heat in all
directions, much of which re-radiated back to the
Earth’s surface. This is why night temperatures are
higher on cloudy nights.
On clear nights, most of the radiated heat from the
Earth surface is lost into space.
Insolation is the amount of solar energy
reaching the Eartht’s surface that is
available as heat.
At an oblique
Almost
vertical
More is lost by absorption and
reflection because of the long
journey. This leaves less to be
used up for heating up the
surface.
Less is lost by reflection. Each
ray has a smaller surface area
to heat up.
• The main control of insolation is latitude. As the
latitude increases, insolation decreases, and the
weather becomes colder.
• Other factors:
- proximity to the sea (coastal cities are cooler in the
summer - light rays penetrate deeply into water and
currents distribute the heat)
- albedo (high proportion of the Sun’s light is reflected
instead of being absorbed)
• Water vapour , carbon dioxide , and cloud droplets
absorb most strongly in the long wavelengths (mainly
trap heat radiation from the land rather than light
radiation from the Sun). They also re-radiate some of
the heat back to the ground – greenhouse effect (keeps
troposphere up to 30°C warmer).
WATER, SOLAR, AND WIND AS
POWER SOURCES
1) Read 122, 123, and 124, and answer the following
questions:
a) Why does the production from each one and
potential for further use vary greatly from country
to country.
b) Comment on the importance (now and in the
future) of these alternative sources.
2) Obtain statistics for energy production in Turkey and
show percentages in a pie or divided bar graph.
• WATER, SOLAR, AND WIND AS POWER
SOURCES
• Water power – Hydroelectric power (HEP)
- Large dams are multi-purpose – water supply,
flood control, electricity generation
- 6% of commercial world energy consumption
- Its importance varies between countries,
because of the physical conditions needed for
its generation do not exist everywhere (very
important in water-rich Brazil, used as a water
supply in water-poor Egypt)
Wind power
- saves on imported energy (oil and natural gas)
- reduce carbon dioxide emissions
- use of favorable generating conditions (many
days with strong winds)
- Fastest growing source of electricity
- less than 1 % of world energy output
- Complaints about wind farms: visual and noise
pollution, bad TV & radio reception, bird deaths
• Solar power
- photovoltaic cells
- to heat water in pipes (solar thermal)
- more common on buildings in hot countries
- Most suited to local use by individuals: making
electricity available to individuals in rural areas,
where there is no access to national power grids
Structure
Composition and function
Sun as an Energy Source