Dear Weather Club Member,

Welcome to the April edition of our Weather Club e-news!

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Here’s a quick preview of this month’s contents
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Cockatoos Ate My Anemometer Cable!! . . . Moonlight Madness . . . We Want Weather Wherever We Web Wander. . . Readers Put in Their Two Cents. . . The (Dust) Devil and Dr. Gilreath . . .You're Brilliant! Answers to Quiz Questions . . . Who You Gonna Call? Davis! . . . Enjoy!

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Cockatoos Ate My Anemometer Cable!!
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Or, Baby, It's STILL C-C-Cold Outside, Not Really! Now this is more like it. Here it is, dreary old tax season, and our Vantage Pro is reading 71°F, and a lovely warm breeze is scrubbing the air. We feel like Californians again! Pale legs are coming out of hibernation, the patio tables are the lunch time place to be, and the birds are chirping and revitalizing the earth by dropping quasi-digested berries onto it via our windshields.

The birds and the bees-and the spiders and ants and worms-have noticed the change in the air, and will soon be showing their appreciation for the lovely high rise accommodations we weather station owners have installed for them. Unfortunately, most of us don't much like the cocoons, webs, carcasses, chewing damage, and uh, poop, our antennaed and feathered tenants leave behind. (Don't worry, Stockholm, [-1°C]; St. Cloud, MN [27°F]; and poor Winnipeg [-4.2°C]; your turn, and your birds, will come.)

In a journalistic coup, the Davis Weather Club E-News has scooped the National Enquirer on a story of bizarre bird cheekiness. Wayne Williams, of New South Wales, Australia told us this scary tale: "Cockatoos are a large white and sulfur-crested bird that live all over Australia. They seem to be getting cheekier in their escapades around my town. I live in Campbelltown, about 35 miles (55 km) southwest of Sydney, New South Wales. Recently my Weather Monitor II stopped showing wind speed and direction. A climb onto the upstairs room was the only way to find out what's going on." Clinging to the roof, Wayne discovered his anemometer cable had been completely chewed through by cheeky cockatoos. "I bared the ends of the fine red wire and twisted them together, then duct-taped the whole cable back to the pole."

Wayne wonders if anyone else has had such problems with birdlife and what preventative measures they came up with. Our technical support manager, Brett, tells that, unfortunately, there is no magical cure to prevent birds or bugs from chewing on those delicious cables. The best you can do is to isolate and secure the cables in such a way that they are not accessible to the hungry (or cheeky) pests. If you'd like to offer up your own solutions, you know the address! (news@davisnet.com)

Since we mentioned it, Brett added that now is a good time to put your weather station through a bit of spring cleaning to remove any winter muck. In general, all external components will benefit from a dusting. Wipe each component down with a soft damp cloth, taking care not to touch the top surface of any solar sensors you may have.

Of all the sensors, the anemometer and rain collector will need the most attention. Clean all the cobwebs off the anemometer and make sure no bugs or debris are lodged between the cups and the anemometer head. You should remove the rain collector cone and, with a soft damp cloth, clean any mud, bugs, or other debris from the tipping bucket mechanism. Also make sure the large cone is completely clean of any winter debris.

While you're out there, check your cables and connections. Make sure that all of your cables are securely attached and not loose and rubbing against anything sharp. Check and re-seat any outdoor connections.

Weather Check Quiz Question 1: Here's one for the up-and-coming weather persons in your house. Spring, and all seasons, are the result of A.) Earth's distance from the sun; B.) Earth's tilt on its axis; or C.) Earth's 24 hour rotation on its axis. (Answer at the bottom of this page.)

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Moonlight Madness
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"The moon was but a chin of gold, a night or two ago, and now she turns her perfect face, upon the world below." - Emily Dickenson.

If you have a Davis Vantage Pro or the Vantage Pro Plus, you know what the current moon phase is. On April 12, the moon was "new" - with "her perfect face" turned all the way away from us. But in just a couple of weeks, that "perfect" face will be better described with one of our favorite earth-space science terms: waxing gibbous. At that point, the moon will appear more than half full, but less than fully illuminated, on its way to a full moon on the 27th. On the way back to a new moon, we'll see another gibbous stage - the waning gibbous. (FYI: the word "gibbous"comes from the Latin for "hunchback.")

During each full moon cycle, or lunation, the moon moves from new moon through waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter, and waning crescent. With a lifespan of an average 29.5 days, the moon's phase can more precisely be described by its "age:" the number of days since the new moon. A lunation is also known as a synodic month.

The moon, while not contributing heavily to our earthbound weather, is of course in charge of tides. (It exerts the same pressure on our solid ground as well, but with less noticeable effect.) It is, however, one of the very few constants for sky watchers: when we see a waxing gibbous moon here in California, so will you, wherever your observation point is. And we all see the same lunar hemisphere that Gallileo first illustrated back in 1609. Because the moon rotates on its axis during the same period as its orbit around the earth, the "back side" of the moon is forever out of our view.

But the moon does contribute heavily to human culture. It is a source of endless mythology, superstitious, and artistic inspiration, to say nothing of romance-inciting! The ancient Mayans saw a leaping rabbit in the moon, carried, they said, as the pet of the moon goddess. The Islamic calendar, as well as the ancient Hebrew calendar, are both based on the moon cycle. The Hindu Karwa Chauth fast cannot be broken until the moon is sighted in the night sky. There is a Tibetan tale about unwise leadership in which monkeys form a chain to rescue the moon that they can see has fallen down the well. Astrologists will tell you where "your" moon is, possibly explaining why you can't stick to a diet or why you love to put things in neat little boxes. Hospital workers and police officers swear people go crazy when the moon is full. From the ancient Chinese Moon Festival and Beethoven's Moonlight Sonata, to Moon Pies and Sailor Moon, the cultural influence of earth's only natural satellite has been ubiquitous and profound.

As for us, the moon, whether waxing, waning or full, whether ringed by a blue-tinged corona or peeking brightly through gray clouds or glowing huge and orange just over the eastern hills, has always been a comforting sort of companion. This month, if you can, show a child the waxing gibbous moon. Show her how to tell whether it is waxing or waning. (Imagine you could cup the moon in one hand; if it fits in your right hand, it's waxing; in your left, it's waning.) If you're old enough to remember, tell her where you were when man first set foot on its surface, and how old she'll be when we next have a "blue moon" (July, 2004). Then maybe sing a little "Blue Moon" for her. Whether she remembers the moon phase name or not, she will always remember the conversation. (Especially the singing part.)

A terrific website for learning more about the moon is www.inconstantmoon.com. For an illuminating story about the how (and when) the phrase "Blue Moon" came to mean a second full moon in one month, check out "Once in a Blue Moon," by Philip Hiscock. It can be found at http://skyandtelescope.com/observing/objects/moon/article_127_1.asp.

And for a great view of the moon and data on its precise "age," check out http://www.fourmilab.ch/earthview/vplanet.html on John Walker's fun and educational homepage (http://www.fourmilab.ch). (Interesting note: the "ch" means the site is from Switzerland, not China!) For an answer to the question, "Why does the moon appear bigger on the horizon than overhead?" click on http://www.badastronomy.com/bad/misc/moonbig.html.

Weather Check Quiz Question 2: What is the difference between a moon halo and moon corona?

Bonus Question: What do we call the study of physical characteristics of moon? (Hint: It's not "Moonology.")

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We Want Weather Wherever We Web Wander
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One of the best things about weather is that yours is not just like ours. We all love to see what Mother Nature is doing in somebody else's backyard! Mike Gardner, of Kokomo, IN wandered over to the Creek family's website in North Pole, AK, possibly to enjoy seeing somebody enduring even colder weather than he was. It didn't work. He writes, "Looking out my window at 91/2 inches of snow accumulated over the last 48 hours, I glanced at my Davis Monitor II display to see that the temperature in North Pole, AK was actually .9 degrees warmer than here in Kokomo."

Several interesting new Weather World 'Round sites went up on our website in March, including Adelaide, Australia; Muurame, Finland; Buxton-Norfolk and Shoreham-by-Sea, UK; Gothenburg, Sweden; Konneuburg, Austria; and Matamata, New Zealand. New U.S. locales include Chandler, AZ; Bellevue, Gretna, and Omaha-Dundee, NE; Middleton, CT; San Francisco, Mill Valley and Granada Hills, CA; and our favorite new page: Ashburn, VA.

Weather Check Quiz Question 3: This one is a "scavenger hunt. Find the Weather World 'Round site that introduces its hometown with this description: "Back in the late 1700's, the first travelers coming up the Wabash River were looking for adventure and a place to start a new life. When they came to the big bend in the river where Bonpas Creek enters the Wabash, they found the place they were searching for. There was plenty of fish and game to eat, a stand of tall timber for building material, and a gentle slope of land to build their cabins."

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Readers Put In Their Two Cents
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Thanks for all the nice e-mail about the E-News. It's always fun to find our mailbox full of kind words and thought-provoking comments.

Don Oliason challenged our thinking on the direction of lightning. We said that the lightning strikes are positive charges moving upward. "It's possibly not worth mentioning," Don emailed, "but this is more accurately described as a stream of electrons moving downwards." True, but it seems the light we see is going upward! We got our play-by-play from Jack Williams, author of The Weather Book, who describes it as electrons first moving down, then positive charges being pulled upward from the ground, then the return stroke of upward moving positive charges causing the light we see. It's beginning to sound a bit like a tom-a-to/tom-ah-to discussion. While we're on the subject, another Don wonders how much faster lightning would be if it didn't zigzag so much. This whole conversation is making us dizzy.

Richard Jubinville gave us an additional answer to the quiz question about what Jacob Bjerknes discovered: the North Atlantic Oscillation, "which pertains," he wrote, "to a low pressure system that sets up in the North Atlantic and causes havoc with New England in winter. But I love it!" (Spoken like a true weather nut!)

Weather Check Quiz Question 4: It's only April, and our Barry Bonds has already hit a bunch of homers. So, in his honor, here's a baseball-weather question. Why do baseballs fly farther in Denver than San Francisco?

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The (Dust) Devil and Dr. Gilreath
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What's it like inside a whirling dust devil?

"Very dusty," according the Dr. Jim Gilreath of the University of Florida's Gulf Coast Research and Education Center in Bradenton, Florida. "You don't want to get in one," he assured us. "The dust is very fine and it gets everywhere - in your eyes and ears and your nose. If your mouth is open, you'll get a lungful. Nasty stuff."

Dust devils differ from "dust plumes," which do not rotate, and "debris clouds" which contain heavier debris and often form beneath a condensation funnel at the base of a tornado. Unlike tornados, dust devils can spin in either a clockwise or counterclockwise direction regardless of which hemisphere they are in. Dust devils rarely cause damage, but occasionally, a dust devil can produce hurricane force winds exceeding 75 mph.

Dr. Gilreath's work puts him in just the right circumstance to know dust devils intimately. He and others are looking for alternatives to the soil fumigant methyl bromide which has been identified as an ozone depleter. It so happens that one of the crops he studies is caladiums, 95% of which are grown in Lake Placid, FL. Dr. Gilreath explained that the conditions in Lake Placid that make for such ideal caladiums also make for ideal dust devil creation. Dr. Gilreath has seen as many as six columns of dust in one field. They zigzag across the field gathering up a tube of the light organic dust, often going right off into the grass at the field's edge.

Dr. Gilreath was not the only one to find out what it's like to stand in the path of a dust devil. One of his trusty Davis EZ-Weather Monitor II weather stations was damaged by one, even though the tripod was anchored by metal spikes reaching three feet into the soil. On this particular day, methyl bromide had been injected into a field of 30 or 40 acres. After injection, the field was covered with strips of thin plastic film which are glued together to form one gigantic sheet covering the entire field. As the wind blew across the sheet, slow undulations began to form and grow steadily until huge waves of plastic rose eight feet into the air.

"Suddenly a large dust devil formed, tore across the rippling plastic and wrapped the poor weather station in a big glob of plastic," Dr. Gilreath recalled. "Even though the tripod was spiked into the ground, the force of the wind and the plastic bent the tripod's legs right over."

Of course, the EZ-Weather Monitor II, once its tripod legs were straightened, went right back to gathering data from the grower's field for Dr. Gilreath to download and study.

Between dust devils and the snoozing tractor operator who mowed down another weather station, Dr. Gilreath is one Davis customer who really appreciates our high quality products. Even his home station should be getting hazard pay, as Dr. Gilreath's home is in the middle of an orange grove, and there the problem is not dust devils, it's lightning. But that's another story altogether…

Want to learn more about methyl bromide? Visit the Methyl Bromide Phase Out website at http://www.epa.gov/ozone/mbr/mbrqa/html. This complete story, with photos, can be found on our website at http://www.davisnet.com/news/stories.asp.

Weather Wise Quiz Question 5: Is this a true statement, or did we see it as a tabloid headline while waiting in line to purchase two cans of dog food? "Previously Unknown Artist, Dust Devil, Shown to Be Mastermind of Mysterious Martian Decoration."

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You're Brilliant! Answers to Quiz Questions
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Question 1: If you said the cause of seasons is B, Earth's tilt on its axis, you are right. The tilt causes one hemisphere to lean toward the sun at different points in Earth's annual rotation around the sun. For an excellent graphic, check out http://www.usatoday.com/weather/tg/wseason/wseason.htm.

Question 2: While both halos and coronas are caused by the effects of diffraction of the moon's light, they differ in appearance. Coronas look like a disk behind the moon, while halos look like a ring around it. Halos are caused by diffraction of light by ice crystals, while coronas result from diffraction by clouds.

Bonus Question: The study of the moon's physical characteristics is the luminous science of selenography.

Question 3: Did you find Grayville, Illinois? Then you know that "in the 200 years since then, the town has grown and prospered and is surrounded by rich farmland and oil wells. But the town's richest asset is the hard-working and friendly people who followed those first adventurers and made Grayville their home. They discovered that it is a great place to live and a great place to raise a family. Guess those first settlers really did find Heaven." Check out the weather in heaven with a click on Grayville!

Question 4: It's because there's more friction in San Francisco. The higher pressure in San Francisco means there are more air molecules packed into the stadium. More molecules mean more friction, which slows the ball down. If Barry hits the ball hit just as hard in Denver, it would go about nine feet farther.

Question 5: True! For years astronomers have wondered who the Martian Jackson Pollack may have been as they observed "decorative" lines and swirls crisscrossing over the surface of Mars. Geologist Ken Edgett, of the Malin Space Science System has the answer: it's Dust Devils! The Martian surface heats the air above it and dust devils form there just as they do in Dr. Gilreath's caladium fields. As they move across the dry, dusty ground of Mars, they leave tracks of various shades depending on whether the surface beneath the thin dust coating is darker or lighter. The Malin Space Science has over 70,000 images of Mars. It also will give you a daily Martian weather report, if you just can't get enough weather here on earth! (Source: Weatherwise® magazine, Sept./Oct.2001.)

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Who You Gonna Call?
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Each month after the E-News goes out, we receive messages back. Sometimes the messages are in response to a story we shared; other times they are a request for help of some kind. We read all the emails, answer those we can, and pass the rest on to the appropriate departments.

We think you should know, though, that if you're interested in the fastest possible reply, news@davisnet.com may not be the best place to send your message. Questions about how things work should be addressed to tech support directly at support@davisnet.com. For general information about the products, such as how much cable comes with a station contact sales@davisnet.com. To request a catalog to be sent to you by mail, click here.

Please continue to send your comments, weather URLs, and story suggestions to news@davisnet.com. We look forward to getting your comments and any responses you have to the E-newsletter. Member participation is what keeps the E-newsletter alive and kicking.

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Well, that’s it for this month. Will be checking in again in May.
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