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Assignments #4

Assignments:

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.

Chapter 4

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.

Chapter 5

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.

page 49

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.

pages 50-51

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.

pages 56-57

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…

pages 58-59

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.

pages 60-62

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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Assignments #2

Your simple assignment is to read the next chapter in your book. Please also remember that you must choose a science project.

Notice the weather; look up, pay attention. Start a weather diary or a series of weather drawings; be sure that you have blank and unlined paper, as well as lined paper for notes, next week in class.

Most of you have been to the online jet stream page. Go again! Print one or two pages, put them in your notebook, and compare the position of the jet stream with the weather of the day. Bring it all to class so we can talk about what you see. Be sure to note the date of the jet stream image that you print and the weather that day.

Bring pictures of clouds; bring your questions.

Now let me take you through your books, page by page.

Eric Sloane 2:  The Anatomy of Air

P. 13 magnitude

ES gives you a good sense of magnitude, explaining how thin is the covering of air on the earth. You remember how I drew the Hadley cells? To be correct, they should have been drawn as tapeworms, instead of balloons! But if I did that, they would be so hard to see that you would not believe that they act as they do.

P. 14-15 low air pressure at high altitudes

Sloane’s remarks about barometric pressure are very interesting, from how the Andean hunters catch birds to how he made cartoons about intestinal gas to warn pilots about the unwisdom of drinking soda before flying in a poorly pressurized air plane.

P. 16 layers of atmosphere

Pay close attention to these measurements; they keep coming up, and you will have a better understanding of everything you read if you know the height of the troposphere, the stratosphere, and the ionosphere, and a tiny bit about them.

P. 17 meteors in the atmosphere

Interesting description of meteor flight. Also a mistake about how the earth looks from the Moon; he thought the continents would be lost in the blue, but they are not, as we know. Only when the earth is cloudy is the land hidden from sight.

P. 18-19 troposphere

This is a really good set of drawings, explaining the variable height of the troposphere. Study it carefully!

Jack Williams chapter 2 How the Sun creates weather

Mainly, this chapter explains how the sun sends a lot of heat to the earth, and this causes many weather patterns. JW also says a lot about solar flares and solar wind, without describing their influence on the weather, which in fact he doubts, but I do not. He notes that they affect our communication systems mainly — but they have some weather effects because ions nucleate raindrops. There is also a longer-term effect, but he follows Jack Eddy in doubting this, see below.

P. 13 Some things to notice:

1) First, let me make a point of philosophy. Jack Williams says the sun creates weather and later that the sun creates energy.

It does not.

It generates energy.

There’s a difference, because to create is to make out of nothing, and the sun has its whole sphere of gas to burn and crush, not nothing. Only God creates from nothing. You can use the word create metaphorically when you produce a work of art, because the beauty of it comes from within you, from your likeness to God the creator. But otherwise it’s just a mistake to talk about anyone but God creating anything. People use the word “create” to mean “make” all the time, and it’s a pity because that makes it no word at all. If it doesn’t have a separate meaning, it needn’t bother being a word, and in time it will die. Use the word properly.

So: the sun generates energy, and this is the main reason for the air movements that we call weather.

2) Williams says – correctly – that the sun is fueled by atomic fusion, and then, rather carelessly, he remarks that nuclear power plants produce energy by fission. In case you are confused by this (as I was for many years) fusion is glomming two atoms into one. Normally, this is only possible with the small atoms at the top of the periodic table. The larger atoms at the middle are only fused in supernovae, and… enough said for today. Fission is breaking up large atoms, and only produces energy if the atoms you break are at the bottom of the periodic table. I can explain more if you want. I just wanted to mnetion the difference between fission and fusion.

3) Actually, even Williams’ first paragraph is a little thoughtless, for he says that the yearlong trip around the sun “creates” a giant engine that drives the weather. Makes, right, not creates?

But besides, long before the yearlong revolution, just the daylong spin of the earth generates a substantial portion of the weather, as you know since we talked about the Hadley cell. You might enjoy reviewing the Hadley cell. Anyway, my experience is that people who have not studied astronomy tend to be a little vague and careless about the difference between the rotation of the earth on its axis and its revolution around the sun. (Sigh.)

P. 14-15 Anatomy of the sun

Good description of the sun’s innards. Notice the size comparison between the earth and one solar flare. We’re a little short of sunspots these days. You could research that for your weather project.

P 16-17 Space weather

1) Nice graphic about the solar wind. Take a good look.

2) I think you know the seasons result from the earth’s trip around the sun. His subtitle is that the tilt makes the seasons, but he only talks about the trip around the sun, not about the tilt, though it’s drawn. Very important. No tilt, no winter and summer, no matter how the earth goes around. If this is news to you, ask me about it; you need to know.

P 18 Jack Eddy: your the compulsory lecture on global pollution

He thinks that man’s pollution is going to do more damage than any shortage of sunspots. I’m not so sure. We’ll probably get a chance to see this in your lifetime, because we are very short of sunspots right now. Very short.

P 18 heat transfer

1)    fairly nice graphic to explain the difference between conduction, convection, and radiation. Not perfect, as the convection is not properly drawn. Do you see the problem? The bubbles of steam should shrink as they rise, and if they float on the top, maybe your water is soapy. When the bubble of steam reaches the top, some steam is released and the rest of the hot water cools and dives below again. This makes the convection cell.

2)    Nice graphic about variations in the reflection and absorption of the sun’s heat.

P 19 & 2   Hot, cold, continental, maritime

Good text and an interesting (mostly obvious, but not all) graphic about heat gains in the world. Important weather vocabulary.

P 21 Building a cold air mass

Nice graphic. But a funny note here: in step six, he begins with the word “eventually” which is about as vague as it gets. “Eventually the wind patterns…  change.” But we know what changes them, right? What makes the cold air leave the poles? It’s heavy; it spreads out, warm air comes in at the top and falls down on it, squeezing outwards… The polar cell.

P 22 Snows and auroras

Nice graphic on how snow makes the cold get colder.

The graphic in the lower corner is deeply in need of informed reconstruction; it’s hilarious actually. Winds never blow. Air is pulled, not pushed. Grow up!

The text has a lot about the solar wind as a source of electrical problems. Interesting; more coming.

P 24 Hot air

Nice graphics on hot air from sea and land.

P. 25 what kills?

He says heat is the USA’s biggest killer. Maybe. Only because we don’t have the coldest weather. The confusing thing is that when people die of cold, they may seem to be be dying of other things, like hunger, for example. You need to eat more when it’s cold, and the garden is not producing. Also, people get lonely when they can’t visit their friends, and more sickness comes from depression. It’s very politically correct to worry more about warming than cooling, but it takes considerable ingenuity to deal with either.

P. 26-27  Wind chill, takeoff, and solar cells

Nice graphics on all these topics, and the text explains them. I didn’t know that planes needed a longer runway in the heat. Interesting. They also need longer runways at high latitudes.

P. 28   JoAnn Jocelyn

Interesting research story; it’s not the solar flares that send the solar wind full of particles this way, but coronal mass ejections – which are usually associated with solar flares, but not always. He doesn’t bother to mention this, meaning I have to research it to check. But while every flare has a CME, not every CME has a flare. Another research report here.

P. 29   1995 Midwest heat wave

OK, this is one where if you don’t get the graphic, it may be because he assumes you know what the book is about to teach. Sorry. But maybe you will get it. Congratulations! It took me most of my adult life to understand the concept of pressure that some people – mostly boys – seem to understand from birth.

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