The Atmosphere Flashcards
What is the air comprised of?
Permanent and Variable Gases
What does Permanent Gas mean, and what permanent gases are in our air?
They do not change based on their volume, nitrogen makes up 78%, oxygen 21%.
What are variable gases and what variable gases comprise our air?
Changing over time or space, or both. Water at 0-4%, and carbon dioxide at 0.0035%.
How thick is the atmosphere?
It is ~480km from the surface to the top (Thermopause). Beyond that altitude is the “exosphere”.
What is the exosphere?
The outer sphere, a near vacuum made up of hydrogen and helium atoms, weakly bound by gravity
What are the three structures of the atmosphere?
Composition, Function, and Temperature.
What are the three layers of atmospheric composition?
Exosphere, Heterosphere, and Homosphere.
__________: outer sphere, a near vacuum made up of hydrogen and helium atoms, weakly bound by gravity, at 180km.
Exosphere
______________: 80km-480km, distinct layers due to gravity. Helium at the top of the [lightest gases] and nitrogen and oxygen near the base [heavier].
Heterosphere
_____________: 0-80km, uniformly mixed except for Ozone O3, ozone in the Ozone Layer [19km-50km].
Homosphere
What gases make up the homosphere? and what are their percentages?
N2 78%, O2 21%, and Argon 1%.
True or False: Nitrogen is the 4th most abundant gas in the human body; however, we cannot acquire nitrogen through the air.
True.
What are the variable gases found in the homosphere? what are their percentages?
Water Vapour H20 @ 0-4% and Carbon Dioxide CO2 @ 0.004%.
True or False: Ice-core data shows how carbon dioxide remained constant until industrialization
True.
Carbon Dioxide in the Atmosphere, CO2, is constantly increasing, global carbon dioxide is measured at _______________.
Mauna Loa observatory in Hawaii.
What is air density?
Air density is the measure of the amount of mass per unit volume.
Density decreases while increasing ________.
altitude
What is the density of air at mean sea level (one standard atmosphere)?
1.2kg of mass per cubic meter.
Density= _______x__________
Mass x Volume
True or False: Gravity accelerates the atmosphere downwards towards the surface; where the atmosphere contacts surfaces, it exerts pressure on those surfaces.
True.
Define Atmospheric Pressure:
The force exerted on a surface by a mass of the atmosphere above that surface.
True or False: Pressure therefore increases as we move up through the atmosphere.
False, it decreases.
Pressure decreases rapidly with height, ____ of the mass is within 30km of the earth’s surface.
97%
Define Pressure:
Pressure is a force per unit of area.
Force = _______x_______
Mass x Acceleration
A pascal of (Pa) of pressure is equivalent to ____ newton of force exerted over a square meter of an area (m2)
One
A _______ is the force required to accelerate a 1kg mass by 1 meter per second per second.
Newton
What annotation is given to a newton?
1 newton of force = 1kg *m/s2
Good to know!!
Unit of atmospheric pressure: 100 pascals (Pa) = 0.1 kilopascals (kPa) = 1 millibar (mb)
What is the Atmospheric Pressure at Sea level (under one standard atmosphere)?
1013.2mb, 101.32 kPa, 101,320 Pa.
True or False: The smaller area of dimension has an increased amount of pressure exertion.
True
How is pressure measured?
With a barometer
What was the name of the first barometer?
Torricelli Barometer
How did the original barometer work?
They fill a long test tube with mercury, tip the tube into a dish with mercury, then resulting height of mercury in the test tube indicates the pressure on the dish of mercury.
In the original barometer; the level of mercury is equivalent to the _____________.
Air pressure
At what depth in water is the pressure equivalent to one standard atmosphere?
10.3m
What measurement does Canada report pressure?
kPa
What measurement does the US use to measure pressure?
inHg (inches of mercury)
_______________: a closed cell gets squeezed by pressure, changing the position of a pen through a system of levers.
Aneroid Barometer
__________________: electrical resistance of a wire changes as a diaphragm wrapped around it is squeezed by pressure, resistance in a circuit changes based on pressure, very sensitive.
Digital Barometer
What type of pressure is “the raw, unadjusted pressure reading”?
Station Pressure
What type of pressure is “adjusted for altitude (and to a lesser degree the air temperature)”?
Mean Sea Level Pressure (MSLP)
What is Mean Sea Level Pressure (MSLP)?
MSLP is the pressure at a given location that would be read if the barometer were at mean sea level
How do we convert atmospheric pressure from kPa to mb?
multiply by 10