Quiz 4 Study Guide

Newton's 1st and 2nd laws of motion. You should be able to state or explain each law. Acceleration can be a change in speed and/or a change in direction. 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.

Forces that determine horizontal winds. Pressure gradient force (PGF), Coriolis force (CF), and friction (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?

Upper level and surface winds.  Upper level winds blow parallel to the contours, surface winds cross the isobars toward low pressure.  Study the examples on the optional assignment.
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?
Can you identify the three forces acting on the wind in the
figure at right? Is this a southern or a northern hemisphere chart?

Sample Questions  Quiz #3: 2, 3, 6, 8, 16b&c, EC2?   Final Exam: 22, 23, 33

Thermal circulations.  Land/sea breezes (see pps 170-173) Horizontal temperature differences create an upper level pressure gradient (air pressure decreases at different rates with increasing altitude in the warm and cold air). Once upper level winds start to blow, a surface pressure gradient is produced. You should be able to determine the directions of the surface and upper level winds in the sketch below (the cloud is a clue). Would you expect to find a land or a sea breeze blowing at the surface? Where would the rising and sinking air be found? Would you expect to see this circulation during the day or at night?
In many ways the Indian monsoon resembles a large scale thermal circulation.  What does the term monsoon mean?

*** Chapter 7 (pps 181-186) ***
One-cell model. Where would the warmest and coldest locations on the earth be found? Remembering that the one-cell model is just a large scale thermal circulation, you would be able to show the directions of the surface and upper level winds, and where surface high and low pressure would be found.

Three-cell model. 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. With which 3-cell model features might you expect to find abundant or infrequent rainfall? Where are the following real world features found (what feature in the three-cell model are they associated with): Bermuda high, Aleutian low, Icelandic low, and Pacific high? Movement of the Pacific high and its effect on Tucson climate, Arizona monsoon.

Ocean currents.  What directions do ocean currents flow off the east and west coasts of the US flow?   Are these warm or cold ocean currents.  What feature in the 3-cell model causes these currents?  Knowing that, what directions would currents off the east and west coasts (near 30 S latitude) of S. America flow?

Sample Questions  Quiz #4: 1, 6, 8, 14, 15, 16.   Final Exam: 19, 27.
*** Chapter 10 ***
Thunderstorms. Ordinary single cell (air mass) and severe thunderstorms (what would make a thunderstorm severe). Thunderstorm occurrence (see Fig. 10.17). Life cycle of an air mass thunderstorm. How can the dissipation of one storm lead to the formation of another? Thunderstorm features and, in some cases, processes that produce them: gust front, anvil cloud, shelf cloud, mammatus clouds, microburst. Wind shear. Why can a storm with a tilted updraft become stronger and last longer than a storm with a vertical updraft? Supercell thunderstorms.

Tornadoes. General characteristics: low pressure core, duration, length of path on the ground, diameter, speed of rotating winds, speed and usual direction of the movement on the ground. Life cycle. What causes the tornado cloud? Tornado season (when do the most tornadoes occur, when do the strongest tornadoes occur). Fujita scale. Tornado winds and damage. Multiple vortices, suction vortices. Mesocyclone and wall clouds. Tornado watches and warnings. Hook echo on radar. Doppler radar - what additional information does it provide that an ordinary radar does not?

Lightning. What creates the electricity in thunderstorms? Normal distribution of electrical charge in a thunderstorm. Intracloud and cloud-to-ground lightning. Sequence of events in a multi-stroke cloud-to-ground lightning flash: stepped leader, upward connecting discharge, first return stroke, one or more dart leaders and subsequent return strokes. Unusual types of lightning, rocket triggered lightning. Lightning hazards and safety. What produces thunder? Determining the distance to a lightning strike.  How/why do lightning rods and cars offer protection from lightning?

Sample Questions.  Quiz #4:, 2, 3, 5, EC2   Final Exam: 2, 6, 9, 47a

Reviews
Mon., Apr. 24
 4-5 pm
 Chávez (Econ) 301
Tue., Apr. 25
 4-5 pm
 Chávez 301
Wed., Apr. 26
 4-5 pm
 Chávez 301