Class Notes (1,100,000)
CA (620,000)
U of A (10,000)
EAS (300)
EAS100 (100)
Lecture 18

EAS100 Lecture Notes - Lecture 18: Vapor Pressure, Thermosphere, Ideal Gas Law


Department
Earth and Atmospheric Sciences
Course Code
EAS100
Professor
Jeffrey Kavanaugh
Lecture
18

This preview shows half of the first page. to view the full 2 pages of the document.
October 23 2014
EAS 3-27
The Atmosphere
Earth has a very specific pressure structure, effectivly increases
exponentially
relative to closeness to the ground. the 'e-folding' height is approx
Mt.Everest.
Ozone is produced by incoming UV striking O2 turning them into free-redical,
monatomic O. These then join up with other O2 to form O3.
At high altitude, (thermosphere) the definition of temperature somewhat
breaks
down, and despite there being very very few air particles, the energy of
these
particles are quite high, thus have very 'high temperature'
Most textbooks state "The saturation vapour pressure, which is also known as
the water vapour capacity of air at any given temperature, cannot be
exceeded"
Wrong. - has to be exceeded for everyday phenomonon, like clouds and
raindrops.
At saturation, the rate of evaporation equals rates of condensation.
Undersaturated - more evaporation than condensation
Oversaturated - more condensation than evaporation
Relative humitity = actual vapour pressure / saturation vapour pressure.
A fall in temperature speeds condensation and slows evaporation.
Dew point - relative humitity = 100%
A decrease in temperature results in a decrease
in the saturation vapour pressure.
Increase in temperature results in increased capacity of evaporation.
Ideal Gas Law
P = pRT
P = pressure
p = density
R = gas law constant
T = temperature
Temp Raises, Pressure Raises
Pressure Increases, Temp Increases.
Dry Adiabatic Lapse Rate
-1.0C/100m
As warm air rises from the surface, air cools, and clouds form.
You're Reading a Preview

Unlock to view full version