- Grades: 3–5, 6–8
The following questions were answered by meteorologist Al Peterlin.
Q: Why do we have wind, and how does it get so powerful?
A: There are several reasons usually working together that make the wind flow. One is differential heating of the earth by the sun. One spot is warmer so air rises and cold air, which is heavier hurries in to fill the void. The same differential heating on a grand scale results in high pressure and low pressure centers on the earth. The air rushing from the highs into the lows are the winds we talk about when we see the fronts on weather maps. Friction (buildings and other things on earth) deflect the air, sometimes squeezing, sometimes opening, increasing or decreasing the wind. And finally, the spinning Earth adds some curvature to the wind like a pitcher throwing a curveball. (Al Peterlin)
Q: Why it is always so windy during the month of March in Virginia?
A: March is a windy month in many parts of the United States and, in fact, the Northern Hemisphere. There are several reasons, but all relate to the strength of the high and low pressure systems that move through our atmosphere. In March, the cold air over the arctic had ample time to pool or collect. At the same time, the sun, which had been heating the far South more strongly than the North, is already starting to move northward (actually the earth's rotation and tilt changes) bringing stronger bubbles of warm moist ocean air. When the strong, cold high from the arctic rushes toward the deep, warm low from the Tropics, the winds gust very strongly, trying to reduce the vast temperature differences between the two air masses. If two weak air masses meet, we experience light winds. When two strong air masses meet, we feel strong winds. (Al Peterlin)