First of all, notice the weather. Record your observations for us to discuss.
Then, because the more you know the more you notice, study the next chapter(s) in your books.
Eric Sloane’s Weather Book ch 4-5
These two chapters are so short, you can read both. Since you have 14 chapters, we’ll be doubling several times.
Sloane compares isobars — lines going along the spatial geography of similar barometric pressure — to elevation lines on a topographic map. Since you probably haven’t seen topo maps, that may not be a completely simple idea, but I think he explains it well. After you read the chapter, find a newspaper or other printed weather source and find the isobars. Bring a copy to class so we can look together at the maps and be sure everyone has the idea clear.
Sloane describes the Coriolis effect. Be sure to study the cartoons — notice that he divides his drawings between the folktales and some unexpected observations. Sloane’s cartoons have lots of information. What does he say about riverbanks? Is there a place near Sioux Falls where you can get a picture of a riverbank eroded on the right more than the left? (On the river’s right as it comes downhill.)
I think you will appreciate Sloane’s drawing of the sledder who slides to the right going down the mountain, and then, aiming to the right, finds himself in a left spiral as he goes into the circular valley. Look at it very carefully, so you can remember how it works.
While we’re talking about unexpected Coriolis effects, go to this website: http://tafkac.org/science/coriolis/coriolis_force_tyson_debunking.html
The whole thing is worth reading, but scroll down maybe 1/3 of the page for a little piece on an engagement between the British and the Germans during World War I, near the Falkland Islands. (You can do a word search for “Falkland” if that’s an easier way to find it.) What happened here?
Chapter 4: Storms and fronts
page 47-48 — if your book is two pages off, sorry. First two pages of chapter 4…
So what is a front? Very simply, it’s the front portion of a mass of moving air. Weather people talk about a front as if it were some kind of object – it’s just the front end of the incoming weather – and being in front, it’s where the action is.
Notice the interesting story about Benjamin Franklin’s investigations of a storm. He was a first-rate scientist and gave up that career to serve our country. Thanks, Ben.
Cold front, warm front, occluded front. The warm and cold fronts are easy. The occluded front is more of a challenge. He says that cold fronts don’t often catch up with warm fronts, but then what’s that on page 56-57 where that’s what’s on the map? Anyway, the point is that cold fronts travel faster, so… So I don’t know how often, but sometimes.
What’s the Beaufort number for winds at 100 mph?
pages 52 – 53, then 54 – 55 (or so)
(I discovered in class that we have different page numbers.]
Anyway, Williams has a two page spread on a warm front moving across the US, followed by a cold front. Take some time with this diagram. Then he has another two-page spread on the same storm becoming an occluded front.
More discussion of weather that travels and of the interaction between upper and lower winds. Notice that the cold front seems to have caught up with the warm front…
This is an inset piece on a specific storm which added high tides to its fury. In an interesting interplay between water and air, between meteorology and astronomy, the storm hit at the very time when tides were high anyway because of the positions of sun and moon. Really, you never know what’s going to be important in a storm.
The chapter ends with a discussion of the interaction between upper and lower air during a storm. Upper and lower winds do not always go the same direction.
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