What is the ideal gas law? What does it describe?
The ideal gas law is expressed as PV = nRT,
It describes the relationship between a gas’s pressure (P), volume (V), number of moles (n), and absolute temperature (T), using the ideal gas constant (R)
It allows us to predict how the atmosphere will respond when one or more of the state variables change
How does pressure effect the weather?
High pressure: clear skies
Low pressure: cloudy
What is the kinetic theory of matter?
tells us that the differences between gases, liquids, and solids
begin at the molecular level and behave differently under different conditions
What is the hydrostatic equation? What does it tell us?
delta P / delta z = -pg
the change in pressure with height is directly proportional to the density of the fluid.
Pressure decreases as height increases (negative sign is to indicate direction) additionally pressure decreases more quickly in cold air as it is more dense.
Define temperature and pressure
Temperature: A measure of the average kinetic energy of molecules in a substance
Pressure: Force per unit of area which depends on the mole
What is Boyle’s law?
If the temperature of a gas is help constant and it’s volume is increased, then the pressure it exerts will decrease
In other words
Volume and pressure of a gas are inversely proportional.
What is Charles’ Law?
If pressure is held constant, an increase in temperature will cause an increase in volume
In other words
Volume and temperature of a gas are directly proportional
What happens to pressure if the volume of a gas is held constant and the temperature increases? What does it suggest?
Pressure will increase
Suggests pressure and temperature of a gas are directly proportional
What is virtual temperature? Describe the formula.
The temperature that dry air would need to be in order to be the same density as regular air.
Tv = t (1 + 0.61r)
● Where T and Tv are expressed in Kelvin, and r is the mixing ratio, the ratio of mass of water vapour to mass of dry air at 20 degrees Celsius, r = 0.015 g/g
● Virtual temperature is HIGHER than actual temperature by an amount proportional to the amount of water vapour in the air
● Tv is used to account for the fact that moist air is less dense than dry air
● Exercises done in class are likely to be on the midterm (important!!!)
Where does wind come from?
air moving from a high pressure to a low pressure
What is the hypsometric equation used for
represents the difference in height between two pressure surfaces
what is a geopotential
work that must be done against the earths gravitational field to raise a mass of 1kg from sea level to that point. (the symbol is a circle w a vertical stick thru it)
How can you convert station pressure to sea level pressure?
u can use the hypsometric equation to normalize the observations.
How many and what times do Met stations make observations?
4
0000, 0600, 1200, 1800 UTC
How many and what times are radiosondes launched?
2
0000, 1200 UTC
Describe different weather fronts, their names and how to interperate them
cold front: cooler denser air replacing warmer (triangles)
warm front: warm air replacing cold (half circles)
occluded front: combination of cold and warm overtaking (circle + triangle 1 side)
Stationary: cold and hot air not really moving
Squall line: active thunderstorm (line with double dots)
