Quiz #4 Study Guide Pt. 1

Newton's 1st law of motion (10-15 pts).  Given a picture of an object's motion, you should be able to determine whether a net force is acting on the object or not. If a net force is present, you should have some idea what direction it must point.  Here are some examples.

Forces that determine horizontal wind (20-25 pts).   Pressure gradient force (PGF), Coriolis force (CF), and frictional force (F) (surface winds only). Rules that determine the direction and strength of these forces. Which force can start stationary air moving? Which of these forces will only change the direction of the wind and not the wind speed? Which one of these forces can only change the speed of the wind?  Which of these forces is always perpendicular to the contours on a weather map, which is always perpendicular to the wind?

Upper level and surface winds (35-40 pts).
Upper level winds blow parallel to the contours, surface winds blow across the isobars toward low pressure.  You should know the directions that upper level winds blow around circular high and low pressure centers in the northern and southern hemisphere.   In each case you should be able to determine the directions of the PGF and CF. Here are lots of examples to study.

How do surface winds blow around H and L pressure centers in the northern and southern hemispheres? Where do you find rising and sinking air motions?  Here are several examples.
Sample Questions from the Fall 2000 quiz packet      Quiz #5: 4, 12, 13, EC2        Final Exam: 10, 13, 18, 26

Thermal Circulations (15 pts).  Land/sea breezes. Horizontal temperature differences create upper level and surface pressure gradients.  Given a clue of somekind (a cloud for example) or one part of the circulation, you should be able to determine the directions of the surface and upper level winds and where the warm and cold parts of the picture are.

Three-cell model (25 pts).
You should know the locations of the following features: ITCZ, equatorial low, horse latitudes, NE and SE trade winds, subpolar low, polar front, doldrums, prevailing westerlies, subtropical highs, polar highs, polar easterlies. You should find each of these features in this figure.  With which 3-cell model features might you expect to find abundant or infrequent rainfall?

Sample Questions         Quiz #5: 1, 3, 6a, 9, 15      Final Exam: 24, 46