Transcript the carbon cycle

The Atmosphere
Characteristics of the Atmosphere
• It is a blanket of moisture-filled air that surrounds the earth
• It consists 78% nitrogen, 21% oxygen, 1% other gases (argon,
carbon dioxide and water)
• It has ozone in its upper layers which absorb harmful UV rays
from the sun
• It protects us from meteors (they vaporize due to the friction
with the atmosphere) SEE ALBERTA CLIP
• It keeps the earth warm enough for us to live
BRRRRRR!! DO YOU KNOW JUST HOW COLD SPACE IS!!
Layers of Atmosphere
Temperature Gradient
• A change in temperature over a distance
****In the troposphere the temperature gradient is 0.65°/100 m in altitude
Example: What is the temperature at the top of an
8000 m mountain if the temperature is 18°C at the
foot of the mountain?
Layers Again….
Layers in Order…(starting from the Earth
upwards)
•
•
•
•
•
1. Troposphere – up approx 12 km
Closest to the Earth’s surface
Where all weather takes place
Air is in constant motion with both vertical and horizontal currents
Pressure decreases as altitude increases
Has very small amounts of ozone
2. Tropopause
•
Contains more ozone than troposphere
•
Is warmer than the troposphere because it absorbs UV rays from the
sun
3.STRATOSPHERE
• 12-50 km above the Earth’s
surface
• Higher levels of ozone than
any other layer
4.MESOSPHERE
• Temperatures are very low
here
• 50 to 80 km above the earth
• Very low density
• Meteors from space usually
burn up in this layer due to
air friction
• Temperatures are very low
here
5.Thermosphere
AKA –Ionosphere
• 80 km to 500 km from Earth’s
surface
• Fewest air molecules
• Also called ionosphere b/c the
Sun’s radiation causes particles
to become electrically charged
ions
• The Northern and Southern
lights (aurora borealis) are
produced by these ions
• These charged particles also
reflect radio signals so they can
travel around the World
6. Exosphere
• Outer limits! SPACE
• The thin, outermost layer
• Very few particles (few hydrogen particles) spread
out very far
-DISCOVERY
COMMERCIAL
Layers of the Atmosphere Activity
• Purpose: to discover how the atmosphere can
be divided into layers based on temperature
changes & heights.
• First: read background info
• Next: Review table 1, label layers & create
graph
• Then: Answer questions 1-5
THE CARBON CYCLE
CHAPTER 2.5
A Little Background Info …
Organic Substances:
• Always contain atoms of carbon and
hydrogen and often contain oxygen and
nitrogen atoms.
• EXAMPLES:
– Proteins, sugars, and fats
Inorganic Substances:
• Matter that doesn’t contain a combination
of carbon and hydrogen atoms
• EXAMPLES:
– Carbon Dioxide (CO2), water (H2O), and
ammonia (NH3)
CYCLING OF ORGANIC MATTER
• The materials used in building the
bodies of living organisms are
limited to the atoms and molecules
that make up the planet.
• To maintain life on Earth, matter
must be recycled.
• Every carbon atom is recycled time
and time again into new life forms.
The Cycle of Matter
•
Fox
CO2 + Energy
Rabbit
Plant
Leaves
Feed Matter
Decomposition
Decomposers
or Organic
Matter
Plant Roots
Inorganic
Materials
Inorganic
Molecules
Bacteria
THE CARBON CYCLE
• Carbon is an element
• Carbon atoms are the basis for all
living things (called organic matter)
and for all matter that was once
living (called detritus)
• Carbon is stored in FOUR places:
–
–
–
–
Living things
The atmosphere
The ocean
The earth’s crust
These storage places are called carbon
sinks.
• Carbon is removed from the
atmosphere by plants when they
photosynthesize to make sugar.
Photosynthesis
Reactants
Products
• 6CO2 + 6H2O + light = C6H12O6 +6O2
Carbon Dioxide + water + light = Sugar ( Glucose) + oxygen
• Carbon is returned to the
atmosphere by plants and by
animals when they respire or
exhale.
Respiration
Reactants
Products
C6H12O6 + O2
= CO2 + H2O
Sugar + oxygen
=
carbon dioxide + water
• Please fill in chart on page 62.
Watch animation
• Photosynthesis and cellular
respiration are complementary
processes. (they go hand in hand)
• The carbon that they use is
repeatedly cycled through both
processes, this relationship is often
called the CARBON CYCLE.
• Most of the carbon that forms
living organisms is released to the
atmosphere or water as carbon
dioxide from dead decaying
organisms.
• Under certain conditions the decay
process is delayed, and the organic
matter may be converted into rock
or fossil fuels such as coal,
petroleum and natural gas.
• This carbon is not released until
the combustion process takes place
through burning the fuels.
Reservoirs for Inorganic Carbon
• Carbon, when not in organic form,
can be found in three main
reservoirs (storage areas):
• The atmosphere
• The oceans
• The Earth’s crust
The Ocean
• Carbon is found in sea shells and
bones. When these fall to the
bottom of the oceans and get
covered with sediment, they
decompose over millions of years to
form oil (one of the fossil fuels).
•
Shells and Bones
(Millions of tonnes of
soil)
Sink to the bottom of the ocean
Covered by sediment (Millions of years)
Form oil (example: Offshore drilling NFLD)
Reservoirs for Organic Carbon
• Organic carbon is also held in
reservoirs – the bodies of living
things.
• All living things die and
decomposition eventually returns
the carbon to the cycle in inorganic
form.
One Important Exception
• Bogs – store huge quantities of carbon in
organic form
• Bogs have very little oxygen, therefore
decomposition is very slow
• Carbon atoms may remain locked away in
dead plant matter (peat) for many years
in a bog.
• When plants decompose in a bog, they
form peat that can get trapped under
sediments over millions of years and
form coal (another form of fossil fuel)
PLANTS
Die in a bog and form Peat
Millions of years and tonnes of
pressure form coal
HOMEWORK
QUESTIONS:
• Page 65
• #1,2,4,5,6a,7ad
Answers
QUESTIONS:
• Page 65
• #1) Photosynthesis and cellular
respiration are complementary
processes because:
– Photosynthesis takes CO2 out of the
atmosphere and makes sugar
– Cellular respiration uses sugar and
puts CO2 into atmosphere
Answers
QUESTIONS:
• Page 65
• 2) Decomposers are important to
carbon cycle because they
decompose or break down dead
plant/animal matter, putting carbon
into soil
• Carbon is then converted into fossil
fuels such as coal, petroleum,
natural gas
Answers
4) Burning of fossil fuels by humans
affects carbon cycle because we are
putting CO2 into atmosphere faster
than new fossil fuels are created.
5a) Carbon is cycled more slowly in
northern ecosystems than in tropics
because it is much colder there.
Bacteria and decomposers are not
as plentiful and work at a slower rate
in colder temperatures.
Answers
5b) Carbon is cycled more rapidly in
grasslands than in bogs because there is
more oxygen available. Bogs have huge
quantities of carbon, but very little oxygen
which is necessary for decomposition to
occur.
6a) Burning of forests could change oxygen
levels in atmosphere because combustion
uses oxygen and produces carbon
dioxide; therefore, there will be less
oxygen in atmosphere.
Answers
7a) Carbon entering atmosphere:
105+60+60+5+2 = 232
Carbon leaving:
120+107 = 227
More carbon entering than leaving
atmosphere!
d) Suggestions to reduce flow of
carbon dioxide into the atmosphere?