Transcript OZONE LAYER Ozone in Troposphere = “Bad” ozone

24.1 The Atmosphere
1. Define the atmosphere…
2. What molecule has the highest concentration
in the atmosphere? ( oxygen, Carbon dioxide,
nitrogen?)
3. Why is the atmosphere important? (3 things)
• The atmosphere is … the layer of gases that
surround the earth
The Function of the Atmosphere:
a. Holds Heat and helps moderate Earth’s temperatures
b. Provides Protection from …
1. Meteoroids
2. High Energy Radiation (UV rays) from the sun
c. Provides gasses essential for life
– Oxygen
– Carbon dioxide
– Nitrogen
Composition of the Atmosphere
a. Nitrogen (78%), oxygen (21%), other gases and
water vapor (1%)
b. Suspended Solid and liquid particles Ash and
smoke from fires or volcanoes
– Salt from ocean spray
a.
OZONE LAYER
Ozone in Troposphere = “Bad” ozone
1. Acts as greenhouse gas (traps heat) and causes
smog.
b. Ozone in Stratosphere= “Good” ozone
1. Made of O3 molecules
2. absorbs UV rays that can be harmful to
plants and animals
3. UV radiation is Thermal Energy which
warms strato.
c. OZONE HOLE = Thinning of ozone layer
1. Where: over poles
2. Cause: chemicals, CFCs
(Chloroflourocarbons), used as coolants in
refrigeration and aerosols, get into
atmosphere and break apart ozone
molecule … allowing more UV in.
Air Pressure: the force on a surface
due to the weight of air
a. The atmosphere
has weight
because of gravity
b. As altitude
increases, air
pressure and
density decreases
c. Measured with
a barometer
Layers of the Atmosphere
• Troposphere:
1. 0-12km (~ 7 mi)
2. Weather & Clouds
3. Greatest air pressure & density
(Gravity pulls air to surface)
4. Temp. DECREASES
with altitude (As air expands it
cools)
Stratosphere
1. 12 km – 50 km (~ 32 mi)
2. Contains ozone layer
3. Temperatures WARM
from -57C to 0C.
4. Upper strat. is warmer
than lower b/c of OZONE
LAYER which is absorbing
UV radiation
http://www.youtube.com/watch?v=FHtvDA0W
34I
Mesosphere
1. 50-80 km (~52 mi),
2. Temps decrease as
altitude increases
3. Top of Meso. Is
- 90 C
4. Very thin air –
moving VERY FAST.
Windy (320 km/hr).
5. This burns up
meteoroids
Thermosphere
1. OUTER MOST LAYER
2. 80 km – outer space
3. TEMP INCREASES w/
Alititude. ( - 90 C to
more than 1000 C)
4. Temps. Increase
because gas molecules
in this layer absorb
solar radiation
Ionosphere
1. Part of
THERMOSPHERE
2. Region of charged
particles (ions) that
overlaps the lower
thermoshere.
3. Molecules absorb
solar energy and b/cm
(+) charged or IONS.
4. Aurora – Charged
particles are
attracted to E’s mag.
Poles – collide w/
ions & glow