introduction to the atmosphere the air around us
TRANSCRIPT
Introduction to the Introduction to the AtmosphereAtmosphere
The air around us.The air around us.
What is the atmosphereWhat is the atmosphere??
• The Earth is surrounded by a blanket of air, which we call the atmosphere. It reaches over 560 kilometers (348 miles) from the surface of the Earth, so we are only able to see what occurs fairly close to the ground.
• This “blanket” moderates temperature, protects us from harmful radiation and supports life.
Composition of the Composition of the AtmosphereAtmosphere
The present composition of The present composition of the atmosphere is:the atmosphere is:
21% OXYGEN (O21% OXYGEN (O22)) 78% NITROGEN (N78% NITROGEN (N22)) 0.04% CARBON DIOXIDE 0.04% CARBON DIOXIDE
(CO(CO22)) ~0.9% ARGON (Ar)~0.9% ARGON (Ar) Besides water vapor, several Besides water vapor, several
other gases are also present other gases are also present in much smaller amounts:in much smaller amounts:
Carbon monoxide (formula Carbon monoxide (formula CO) CO)
Neon (Ne) Neon (Ne) Oxides of nitrogen Oxides of nitrogen Methane (CHMethane (CH44) ) Krypton (Kr) Krypton (Kr)
THE FIRST BILLION YEARSTHE FIRST BILLION YEARS
The Earth's surface The Earth's surface was originally molten, was originally molten, as it cooled the as it cooled the volcanoes out gassed volcanoes out gassed out massive amounts out massive amounts of: of:
CARBON DIOXIDE, CARBON DIOXIDE, STEAM (HSTEAM (H22O vapor), O vapor), AMMONIA and AMMONIA and METHANE. METHANE. There was There was NO NO
OXYGENOXYGEN. The STEAM . The STEAM condensed to form condensed to form water which then water which then produced shallow seas. produced shallow seas.
Layers of the AtmosphereLayers of the Atmosphere
The TroposphereThe Troposphere TroposphereTroposphere: The : The
troposphere is the troposphere is the lowest region in the lowest region in the Earth's (or any Earth's (or any planet's) atmosphere. planet's) atmosphere.
On the Earth, it goes On the Earth, it goes from ground (or water) from ground (or water) level up to about 11 level up to about 11 miles (17 kilometers) miles (17 kilometers) high.high.
Weather and clouds Weather and clouds occur in the occur in the troposphere. troposphere.
In the troposphere, In the troposphere, the temperature the temperature generally decreases generally decreases as altitude increases. as altitude increases.
The StratosphereThe Stratosphere
The stratosphere : 11 and The stratosphere : 11 and 31 miles (17 to 50 31 miles (17 to 50 kilometers) above the kilometers) above the earth's surface. earth's surface.
The earth's The earth's ozone layer is layer is located in the stratosphere. located in the stratosphere. Ozone, a form of oxygen, is Ozone, a form of oxygen, is crucial to our survival; this crucial to our survival; this layer absorbs a lot of layer absorbs a lot of ultraviolet solar energy. solar energy.
Only the highest clouds Only the highest clouds (cirrus, cirrostratus, and (cirrus, cirrostratus, and cirrocumulus) are in the cirrocumulus) are in the lower stratosphere. lower stratosphere.
The World’s Highest Skydive!The World’s Highest Skydive!
The Flight of Joseph KittingerThe Flight of Joseph Kittinger On August 16, 1960, Air Force Captain Kittinger jumped from an On August 16, 1960, Air Force Captain Kittinger jumped from an
open gondola suspended from a giant helium-filled balloon at open gondola suspended from a giant helium-filled balloon at 102,800 feet (31,300 meters) in the Project Excelsior III flight. 102,800 feet (31,300 meters) in the Project Excelsior III flight.
The goal of the Excelsior program was to develop a parachute The goal of the Excelsior program was to develop a parachute by which a man could survive escape at extreme altitudes.by which a man could survive escape at extreme altitudes.
The ascent, through temperatures that fell to 94 degrees below The ascent, through temperatures that fell to 94 degrees below zero, took an hour and a half. Failure of his life-support system zero, took an hour and a half. Failure of his life-support system above 60,000 feet would have meant almost instant death.above 60,000 feet would have meant almost instant death.With that and other hazards in mind, he stepped out of the With that and other hazards in mind, he stepped out of the gondola and plunged through the stratosphere, reaching gondola and plunged through the stratosphere, reaching supersonic speed somewhere between 614 - 714 miles per supersonic speed somewhere between 614 - 714 miles per hour.hour.
Between 90,000 and 70,000 feet, he experienced great difficulty Between 90,000 and 70,000 feet, he experienced great difficulty in breathing.in breathing.
At about 50,000 feet, his free-fall speed had dropped to 250 At about 50,000 feet, his free-fall speed had dropped to 250 miles an hour in the denser atmosphere.miles an hour in the denser atmosphere.
Project Excelsior IIIProject Excelsior III After he had fallen for four After he had fallen for four
minutes and 37 seconds, minutes and 37 seconds, Kittinger's main chute opened, Kittinger's main chute opened, and some eight minutes later he and some eight minutes later he landed at the White Sands landed at the White Sands Missile Range in New Mexico Missile Range in New Mexico with no permanent injuries but with no permanent injuries but with three world records; the with three world records; the highest open-gondola balloon highest open-gondola balloon ascent, the longest free-fall, and ascent, the longest free-fall, and the longest parachute descentthe longest parachute descent
He was also the first man to go He was also the first man to go supersonic in free-fall. Kittinger supersonic in free-fall. Kittinger had proved that man could had proved that man could function in function in near-space and that and that parachuting from very high parachuting from very high altitudes was feasible.altitudes was feasible.
The Troposphere vs. the The Troposphere vs. the StratosphereStratosphere
The MesosphereThe Mesosphere The mesosphere : 31 and The mesosphere : 31 and
50 miles (17 to 80 50 miles (17 to 80 kilometers) above the kilometers) above the earth's surfaceearth's surface
Temperatures in the Temperatures in the mesosphere drop with mesosphere drop with increasing altitude to about increasing altitude to about -100°C -100°C
In the mesosphere In the mesosphere temperatures that quickly temperatures that quickly decrease as height decrease as height increases. increases.
The mesosphere is also the The mesosphere is also the layer in which a lot of layer in which a lot of meteors burn up while burn up while entering the Earth's entering the Earth's atmosphere. From the Earth atmosphere. From the Earth they are seen as shooting they are seen as shooting starsstars..
The ThermosphereThe Thermosphere Temperature increases Temperature increases
with altitude. Due to the with altitude. Due to the Suns energy. Suns energy.
Temperatures in this region Temperatures in this region
can go as high as 1,727 can go as high as 1,727 degrees Celsius. degrees Celsius.
Radiation causes the Radiation causes the scattered air particles in this scattered air particles in this layer to become electrically layer to become electrically charged (see ionosphere), charged (see ionosphere), enabling radio waves to enabling radio waves to bounce off and be received bounce off and be received beyond the horizon. beyond the horizon.
The IonosphereThe Ionosphere The The thermosphere thermosphere can can
be identified in two parts- be identified in two parts- the ionosphere and the the ionosphere and the exosphere.exosphere.
IonosphereIonosphere: 70 km-640 : 70 km-640 (about 400 miles = 640 (about 400 miles = 640 km). km).
It contains many ions and It contains many ions and free electrons (plasma). free electrons (plasma).
Auroras occur in the Auroras occur in the ionosphere.ionosphere.
The Aurora , or northern The Aurora , or northern lights are a result of lights are a result of particles from the sun particles from the sun coming into contact with coming into contact with the Earth’s atmosphere.the Earth’s atmosphere.
The ExosphereThe Exosphere ExosphereExosphere: the outermost : the outermost
layer of the Earth's layer of the Earth's atmosphere. atmosphere.
From about 400 miles (640 From about 400 miles (640 km) high to about 800 km) high to about 800 miles (1,280 km). miles (1,280 km).
The lower boundary of the The lower boundary of the exosphere is called the exosphere is called the critical level of escape, critical level of escape, where atmospheric where atmospheric pressure is very low (the pressure is very low (the gas atoms are very widely gas atoms are very widely spaced) and thespaced) and the
temperature is very low temperature is very low In this region, atoms and In this region, atoms and
molecules escape into molecules escape into space.space.