Download earth`s atmosphere - PAMS

EARTH’S ATMOSPHERE
Features of the Earth
1. Land – lithosphere
2. Water – hydrosphere (97% salt water, 3% fresh water – 85% of the earth’s fresh water is
frozen)
3. Air – atmosphere
Ozone layer – the umbrella for life. Absorbs the UV rays from the sun. It is located 30 km
above the earth’s surface. Made up of three oxygen atoms chemically combined.
The Atmosphere
1. Past Atmosphere – mostly methane and ammonia; had more carbon dioxide than present
day and very little oxygen. Early photosynthetic life such as cyanobacteria (blue-green
algae) consumed the carbon dioxide and released oxygen. This allowed animal life to be
possible.
2. Present atmosphere – Nitrogen 78% (used to make proteins); Oxygen 21% (essential for
respiration); Carbon dioxide 1% (used by plants to make food); Water vapor (forms
precipitation/clouds); Trace Gases, and dust particles.
Atmospheric Layers: Divided according to the change in temp.
1. Troposphere – closest to the earth, most weather occurs here. Temperature drops 6.5 C
each kilometer above the earth.
2. Stratosphere – from the tropopause up to 50 kilometers, extremely cold around – 60 C,
Jet stream is here, ozone layer is here, also.
3. Mesosphere -- -100ΊC, thin clouds of ice, protects Earth from meteoroids (friction).
Clouds in this area are usually oddly colored or shaped.
4. Thermosphere – begins at 80 km, air is very thin, may reach 2000 C or more (caused by
absorbing UV rays)
 Ionosphere – lower part of the thermosphere, used for radio communication, made
up of ions (charged atoms)
 Exosphere – upper part of the thermosphere, artificial satellites orbit this area
•Magnetosphere – this area extends beyond the atmosphere.
Operated by the Earth’s
magnetic force. Begins at about 1000 km and extends to 4000 km on the side of the earth
that faces the sun, and even farther on the other side. Made up of positively charged protons
and negatively charged electrons.
•Van Allen Radiation Belts are formed when the magnetosphere catches the protons and
electrons given off by the sun, a concentrated belt of high radiation. This causes the auroras
(Northern and Southern lights) Radio signals alert scientists to when this will occur.
HEAT ENERGY
•Weather: the daily conditions of the atmosphere
•The factors that interact to cause weather are heat energy, air pressure, winds, and
moisture
Heat Energy and the Atmosphere
•The Sun’s energy that is absorbed by the Earth is spread throughout the atmosphere, some
is reflected back into space
Heat Transfer
1. Conduction is the direct transfer of heat energy from one substance to another (warm
clothes from the dryer, rubbing hands together)
2. Convection is the transfer of heat energy in a fluid (lava lamp)
3. Radiation is the transfer of energy by waves such as light (through space)
The Greenhouse Effect
•Infrared light is absorbed by carbon dioxide, water vapor, and other gases in the atmosphere
and forms a blanket that traps heat around the Earth.