METR 1111, Fall 2002
Due: 10/28 at beginning of class
PART I - Use the lecture notes to answer the following:
1. (2 pts) What are the two really tough obstacles for tropical meteorology
that mid-latitude meteorology does not face?
2. (1 pt) What does it mean to say that a hurricane is intensifying?
3. (1 pt) What does it mean to say that a hurricane is strengthening?
4. (1 pt) What does convergence mean?
5. (1 pt) What does divergence mean?
There is a fundamental concept in meteorology and fluid dynamics called "conservation of mass". That means that the mass of air flowing into an area is equal to the mass of air flowing out of it (applies in 2-D and 3-D cases). If winds are coming together at the surface of the earth, air can't flow into the ground so it must rise up. If winds are pulling apart at the surface, it draws air down to replace the air that is leaving. You can think of the tropopause (the boundary between the troposphere and stratosphere) as a lid that acts like an upside-down ground in the sky. In other words, the tropopause is a boundary that air can't flow through just like the ground. Most weather occurs in the troposphere because the stratosphere is very stable and it acts like a boundary.
6. (1 pt) In a column of air stretching from near the surface to near the tropopause, if you have convergence of the winds at the surface and divergence aloft, would you expect upward or downward motion?
7. (1 pt) What about the other way around: divergence at the surface and convergence aloft?
8. (1 pt) Surface low pressure areas generally have rising motion so they are associated with which scenerio? question 6 or 7
9. (1 pt) Surface high pressure areas generally have subsidence (sinking motion)
so they're associated with? question 6 or 7
We also know that winds rotate cyclonically around low pressure centers, which is in the counterclockwise direction in the northern hemisphere. Winds rotate anticyclonically (clockwise) around high pressure areas.
10. (2 pts) A healthy hurricane always has a surface low pressure (by definition) and usually has _________ pressure aloft, allowing for ___________ outflow aloft that pumps away "exhaust". Choices: HIGH, LOW, CYCLONIC, ANTICYCLONIC
PART 2 - Read the to the following website tutorial: http://www.met.tamu.edu/class/Metr151/tut/hurricane/hurrmain.html
It should take you 20-30 minutes. The optional part is, well, optional, but
it's very informative.
11. (1 pt) What is the only hurricane basin that can experience tropical cyclones
at any time of the year?
12. (1 pt) What are the only 2 direct factors that affect the initial formation of a tropical cyclone.
13. (1 pt) Give me the simplest definition of vorticity.
14. (1 pt) What is relative vorticity?
Just wait till your dynamics courses. Vorticity is pretty much the foundation
of dynamics.
15. (2 pts) What are the 2 types of wind shear?
16. (1 pt) In the eye wall replacement cycle, why does the outer eyewall win?
17. (1 pt) What is the "dirty" side of a hurricane? left front, right front, left rear, or right rear