Our atmosphere
Important mixture of gases that sustain life
on Earth
 480km (300 miles) thick
 Beyond the atmosphere is the EXOSPHERE
 Contains small quantities of hydrogen and
helium

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Major
components of
the
troposphere
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Major Atmospheric Components

Nitrogen



Originates mostly from volcanic sources
Without nitrogen there would be no life
Oxygen


By-product of photosynthesis
Concentration of oxygen varies with latitude
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
Argon



Constitutes almost 1% of the atmosphere
Not necessary for life but it used for some economic
purposes
Carbon dioxide


By-product of life
Important for keeping atmosphere warm


increases in CO2 can cause an increase in atmospheric
temperature
Water vapor

Variable from near 0 – 4 %
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The
Atmospheric
Profile
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The Atmosphere
The thermosphere
The mesophere
The stratosphere
The troposphere
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The Troposphere (weathersphere)

Water vapor, clouds, pollution, and life occur
within the troposphere

~ 18km (11 miles) thick at equator; 12 km (8
miles) thick in the mid-latitudes; and 8km (5
miles) thick near the poles

Top of troposphere known as the tropopause
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Lapse Rates in the Troposphere

As we go upwards in the
troposphere, the temperature
decreases

6.4°C/1km or 3.5°F/1000ft =
AVERAGE


This number is not that
important
Can vary considerably with
varying weather conditions
and locations
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The stratosphere

Temperatures increase from -57°C at the base
of the stratosphere to O°C at the top (50km
above Earth’s surface)

Why?

Top of the stratosphere is called the Stratopause
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The mesophere




50 – 80 km above Earth’s
surface
Outer boundary known
as the mesopause
Temperature drops from
O°C to - 90°C at the
mesopause
Occasional coalescence
of cosmic and meteoric
dust form clouds
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The thermosphere


Upper surface
known as the
thermopause
Temperatures
increase to ~1200°C
at the thermopause
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Atmospheric
function

Two main zones


The ozonosphere
The ionosphere
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Functions of
the
atmosphere
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Ozonosphere and Ionosphere


OZONOSPHERE
Contains a high level of
ozone

Efficiently absorbs UV
wavelengths of energy

Ozone is being depleted due
to human activity



IONOSPHERE
Efficiently absorbs
cosmic, gamma, x-rays,
and UV wavelengths of
energy
Recent rebound
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

All the Earth’s energy
ultimately comes from
the sun
Weather and climate are
ultimately driven by




The energy gain from the
sun
The Earth’s position
relative to the sun
Electromagnetic spectrum
Mr. ROY G BIV
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HOW TO REMEMBER THE ORDER
OF VISIBLE LIGHT
ROY G BIV







RED
ORANGE
YELLOW
GREEN
BLUE
INDIGO
VIOLET
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Solar radiation and Earth’s reradiation
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