Advanced Dynamical Meteorology (Meteo 422)
Project One: Vorticity Generation and Tornadogenesis

In this project we apply knowledge of the vorticity equation to the question of tornadogenesis. You will be given an article from the journal Nature that looks at long term variations in tornado numbers and poses a reason for the changes that depends on vorticity. This article elicited many interested responses. Based on your understanding of vorticity, you will be asked to assess both the original article and the published responses to this article.

The article this project centered on is:

Isaacs et al. (1975): "Effect of vorticity pollution by motor vehicles on tornadoes". Nature, 253, 254-255.

Another article by Morton (1984) covers many basic examples of vorticity generation and diffusion, from a classical fluid dynamics perspective. While this may not seem too much like "real meteorology", these examples form the building blocks of the types of flows we observe and forecast in the real atmosphere and so can be extremely useful tools. I recommend that you use this article as background for your thinking about the project:

Morton, B. R., 1984: "The generation and decay of vorticity". Geophys. Astrophys. Fluid Dyn., 28, 277-308.

PROJECT 1, Part A: Individual Written Critiques of Isaacs et al. (1975)

In the week of 14-18 September, you will have no lectures. By the time of our first discussion class (scheduled for Friday, 25 September), each person will arrive with a written evaluation of both the article and the responses completed. This only needs to be one to two pages. You will hand these to me as you enter the room.

PROJECT 1, Part B: Group Discussion and Consensus Paper

I will assign you each to a discussion group when you arrive. In your groups (of 3-5 people) you will discuss the article and responses. You will form a group position. Each member of the group will write a summary of the group position and any points on which they dissent from the group (with justification) by the next discussion class.

It is quite possible that your group won't come to full agreement on this topic in the single class period provided. In order to complete this project properly, you will probably want to schedule some more discussion time out of class.

PROJECT 1, Part C: Class Discussion

When you arrive at the second discussion class, you will hand me your second piece of written work, describing your group's position and your own additional ideas. You must all be ready to defend these ideas. This will be a general class discussion, but I will call on individuals (hiding won't help!).

Approach to Project One

Essentially, approach this as if you were going to be publically reviewed by an audience of your peers (or, at least, folks more scary than we can drum up here at Penn State). This means that you have to:

(1) Be very attentive to the facts. You cannot accuse the authors of a lack of attention to the literature if you cannot cite literature (probably class notes or textbooks) that contradicts their arguments;
(2) Be constructively critical of their arguments. Resort to the equations (!), scaling arguments, etc.;
(3) Think carefully about what you have learned about vorticity and apply it!;
(4) Think carefully about what you know about cars and trucks and apply it;
(5) Evaluate the quality of the responses. Evaluation (of either main article or following) does not mean saying "I think Bloggs does neat thunderstorm stuff, so I'll take his word for it";
(6) Refrain from writing disparagingly about the authors. In a public debate it is not fair game to question an author's authority because of their affiliation, for example.

As meteorologists, you will be expected to communicate information about the weather and climate constantly, and to a wide variety of people. Therefore, I will give no allowance for sloppy writing. I expect professional efforts here.

Summary of Deadlines:

  • No classes 14-18 September
  • Paper A due and first group discussion for Project 1 Friday, 25 September
  • Paper B due and second class discussion on Thursday, 1 October
  • There is NO Paper C for Project 1

    • Back to the class homepage...

    Last Updated: 3 September 1998