Ideal Gas Law (15 pts).
This is
a
microscopic-scale explanation of air pressure. Two equations:
P = N k T / V & P = ρ
R
T
N is the number of air molecules in
a
volume V, T is temperature and ρ is
density. R and k are both constants (you can pretty much
ignore them). You
should be able to determine what will happen to the
pressure in a rigid container or something flexible like a balloon if
you change
the variables in the
equation above. What variables could you change together in such
a way
that the pressure
would stay constant? Charles' Law. In the atmosphere why is
warm air normally low density air (cold air normally high density air)?
Upward and
downward forces (10 pts).Vertical
forces
acting
on
air
parcels
(the
strength
of
one
of
the
forces depends on the air inside the parcel, the
other on the air outside the parcel). These two forces are usually in
balance. What happens to the balance when you warm or cool a parcel of
air? Basically you should be able to explain why a balloon of hot
low density air rises and a balloon of cold high density air
sinks.
Archimedes
Law (5 pts).
An
object immersed in a fluid (this can be a liquid like water or a gas
like air)
experiences an upward bouyant force that is equal to the weight of the
fluid displaced by the object. Basically objects that are less
dense that the fluid around them float, objects that are denser than
the fluid surrounding them sink. What causes the upward bouyant
force (it's the same upward force mentioned in the section above).
Sample
questions
Quiz #1: 13,
14, 16, 17, EC2 Final
Exam: 19, 22
Station
model notation (15 pts).
How and where are the following weather variables plotted: cloud cover,
temperature, dew point temperature (typical values for
Tucson), wind direction and speed, common weather symbols (rain, snow,
fog, rain shower, thunderstorm, tropical storm and hurricane),
pressure. Units. After pressure is measured, what important
adjustment
is made before the pressure is plotted on the surface map? Why is that
necessary? Average and typical range of sea-level pressure values.
Surface weather maps
(45 pts).
A new map is prepared hourly. What
time zone or time reference is used? 24-hour clock. Isobars and
isotherms. Small
horizontal
differences in pressure cause the wind to blow. Air motions around high
and low pressure centers (northern hemisphere). Strong and weak
pressure gradients. Convergence and divergence. Rising and sinking air
motions.
How do wind motions around highs and low affect the
temperature pattern? Cold fronts and warm fronts (where is the warm and
cold air, what direction are the fronts moving).
The following material won't be on the quiz: Upper level charts.
Ridges
(warm air below) and troughs (cold air below). Winds blow parallel to
contour lines and from west to east.