Name ____________________________________________

We are discussing the scientific method in lecture. The first three steps are listed below under the definition.

Scientific Method -- An organized approach utilized to systematically study and solve problems of the natural world.

1. Define a Problem: Obtain and/or examine data and discern a pattern of

2. Make a Hypothesis: Make a first guess about the reasons for the pattern or problem based upon proven principles or understood causes/effects.

3. Test the Hypothesis: See if the same hypothesized cause is associated with the same effects in other places, or for other times etc.

In this lab exercise, you will constsruct streamlines on the basis of weather information (data). You will then discern patterns in the streamlines.

And then you will apply a proven principle on (on a level surface, in the absence of other effects, air blows directly from areas of higher values of pressure to areas of lower values of pressure) to form a hypothesis.

Then you will test the hypothesis on a different weather map. In reality, you'd need to test the hypothesis on many weather maps to "prove" the stated relationship statistically.

1. Draw streamlines on this chart (discussed in class). (15 points)


2. What is the pattern you discern in the streamlines? (10 points)

(Answer in complete sentences, in this space, or on the back, or on separate sheets)

The pattern that I discern is that the air appears to be blowing counterclockwise, directed towards a common point in southwestern Pennsylvania.





The chart below shows the same weather map with an analysis of isobars on it. The isobars are labeled in whole millibars with the 10 or 9 dropped off.



3. Using acetate and the lighttable, as explained in class, transfer your streamline analysis onto this chart.

(a) Formulate a "rule" relating the streamline pattern to the isobar pattern shown; (15 points)

It appears that the air is moving across the isobars from higher to lower pressure, but the air is also moving counterclockwise with respect to the center of the low.



(b) A general principle in meteorology is that in the absence of other effects, on a given level, like sea level, air tends to move from higher values of pressure to lower values of pressure. Explain if your streamline pattern generally matches this rule, substantiating it.(15 points)

(Answer in complete sentences, in this space, or on the back, or on separate sheets)

It generally matches what you'd expect from that principle. But for that principle to exactly work, the air would be moving at right angles to the isobars. It is not quite doing that, but moving at an angle with respect to the isobars, so that it appears to be spiraling around and into the low.





(c) For this rule to work absolutely, air should flow at right angles from higher valued isobars to the lowest pressure on the map, called a "low pressure area" or "cyclone." How would you modify your rule in 3(a) to account for the difference between your analysis and what would be expected by the general principle. (15 points)

I'll start you out:

General Rule for Sea Level Weather Map

On the sea level weather map, air spirals __counterclockwise (counterclockwise/clockwise) and __inward__ (inward, outward) relative to areas of low pressure.

4. The last step in the scientific method shown above is to test the hypothesis or principle you formulated by looking at many different sea level weather maps. Here's one from the last Lab.


Draw streamlines on this chart; (15 pts)

Does the relationship of the streamlines relative to the isobars generally conform to the General Rule for the Sea Level Wetther Map you developed in 3 (c) above? Explain. Answer in two or three complete sentences. (15 pts)

(Answer in complete sentences, in this space, or on the back, or on separate sheets)

The sealevel weather map shows a low pressure area. According to my hypothesis above, air should be moving from higher values of pressure to lower values of pressue, and inward relative to the area of lowest pressure. The streamlines verify that. However, the streamlines also show the spiral, which we need to explain at some point.