Davis
Instruments Weather Club
November 2002
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of this Month’s Contents
Davis,
the Good Santa-Samarian
We just checked
the NOAA's
North Pole live cam and there, just barely visible in the dark
polar morning, is a hastily scrawled note in the snow. It's hard
to make out, but we think it says, "Help! Elves overworked! Too
many good boys and girls, too few days left. Cocoa supplies dwindling.
Send reinforcements."
Since our own
elves are the California kind whose tiny fingers turn blue and stiff
when the temperature drops below 68ºF, they flat out refused to
hop on our North Pole Express bus. (There's nothing more stubborn
than a California elf…) But, Santa, we've heard your cry! We've
increased production on the hottest grown-up toys on your list!
We're cranking out Vantage Pro and Weather Monitor weather stations,
making sure our shelves and distributors are well-stocked. We've
even added a brand new product for the weather person with everything
(see below).
We've also
mailed our new catalog just in time for holiday shopping. (Check
your mailbox - if you don't get one go to our website
to request one in the mail; or download
the catalog. It's full of great gift ideas. May we suggest the
Weather
Echo, our new Weather
Envoy , or our Weather
Forecasting Quick Reference Cards? For the weather person who
truly has everything, how about our Davis caps
and shirts?
So Santa, you
can cross all the technologically savvy, weather-loving, sophisticated,
extra-intelligent, financially wise, and good-looking boys and girls
off your list. We've got them covered. (BTW: Our customer service
number is 1-800-678-3669.)
Weather
Check Quiz Question 1: It's late Christmas Eve eve, December
23, just one day after Winter Solstice, at the workshop at the North
Pole. Although they had to work into the wee hours, Santa and his
elves have all the toys and weather stations ready to load into
his sleigh. He tells his elves to get a good night's rest and be
ready for a long day of sleigh-loading. "Be here at sunrise!"
he commands. The elves are grinning and snickering. When will they
show up for their next day's work?
New
Weather Envoy Lets Your Console Escape the PC
When we set up
our Vantage Pro, the teen techy at our house insisted that the WeatherLink
software be installed on the computer in his bedroom. That meant
that anybody who wanted to check out the current conditions as displayed
on the console had to endure music, uh, not to one's taste, as well
as the occasional pre-laundered hockey sock.
The solution
has arrived! The Davis Weather Envoy
has come to the rescue. The Weather Envoy receives data from the
Vantage Pro and posts it to the computer through your WeatherLink
data logger, without going through a console. It offers a solution
to those who want to keep the console in one location and the computer
in another. It can also be used in field stations inside our Multi-Purpose
Shelter where no console is needed.
At just about
one-third the size of the Vantage Pro console, it can be inconspicuously
mounted on a wall or used on a desk. It includes its own barometer
and humidity sensors, just like those on the Vantage Pro console.
It is available in both wireless and cabled versions, both of which
include an AC-power adapter. The wireless version may also be run
using three AA batteries. Batteries should also be added to the
cabled station for backup during power outages.
The wireless
Envoy sells for $195; the cabled for $165.
(P.S. Makes
a great gift!)
Was
there a Lapse in the Lapse Rate Formula?
John Murphy,
of Tennessee wrote to say he enjoyed the October E-News (and his
new Weather Echo which is "great for an upstairs room"); however
he was confused by Bob Bruneau's contribution to our Weather Check
Quiz. He asked, "If the normal lapse rate is 2 deg C (3.6 deg F)
per 1000', why did the example of the FAA test question divide the
difference between dew point and temperature by 4.4 instead of 3.6?"
Ron Rowland
was equally confused. "Evidently from your recent E-News the FAA
has changed the standard lapse rate from 3.2 F / 1000 ft to 4.4.
Since when?"
Bob, being the
good guy that he is, took the blame for confusion, but explained
that his calculation is correct. "My mention of the 2ºC was mixing
apples and oranges, because the expected lapse rate varies with
moisture content."
For those who
really need to understand this concept, Bob forwarded this explanation
by William K. Kershner in his book, The Student Pilot's Flight Manual.
"…clouds are
formed by moist air being cooled to the point of condensation, and
this leads to the subject of lapse rates.
"For air, the
dry adiabatic lapse rate is 5.5ºF per thousand feet. (Adiabatic
describes a process during which no heat is withdrawn or added to
the system or body concerned). The normal lapse rate of 'average'
air is 3.5ºF (2ºC). The moist adiabatic lapse rate is produced by
convection in a saturated atmosphere such as within a cumulus cloud.
At high temperatures it will be in the vicinity of 4-5ºF. The dew
point lapse rate is about 1ºF per thousand feet.
"For cumulus-type
clouds that are formed by surface heating, the base of the clouds
may be estimated by the rate at which the dry lapse rate 'catches'
the dew point. (Dry lapse rate is 5.4ºF and dew point drop is 1ºF
per thousand, so that the temperature is dropping 4.4ºF faster than
the dew point per thousand feet.) Assume the surface temperature
is 76ºF and the dew point is 58ºF, a difference of 18ºF. Dividing
this number by 4.4, you find the temperature and dew point make
connections about 4000 feet -- the approximate base of the clouds.
This works only for the type of cloud formed by surface heating."
Now you can
count yourself fully informed on yet another topic. Next time the
subject of Adiabatic Lapse Rate comes up at a cocktail party, you'll
be ready to leap into the conversation. (Thank you Ron, John, and
Bob.)
Weather
Check Quiz Question 2: Your spouse is planning a backyard
get-together for tomorrow afternoon. Clouds are high cirrocumulus,
a "mackeral sky," surface winds from the NE to S. What
do you advise about the wisdom of an outdoor event?
Spider
vs. 747? He Predicts the 747 Wins in a TKO
David Damouth
was displeased by one of our September issue's Weather Check Quiz
questions that suggested that a cable of dragline spider silk as
thick as a pencil could stop a 747 in mid-flight.
He wrote, "Did
you do your homework on this one? It appears to me that it is at
least an exaggeration, if not an outright fabrication.
"Your article
states that spider silk has a tensile strength of around 300,000
pounds per square inch. The wooden pencil on my desk has an area
of .066 inches, so the pencil-thick cable would have a breaking
strength of about 20,000 pounds.
"A 747 has a
maximum thrust of about 228,000 pounds (depending on model - this
is a typical value). I couldn't find any documentation of the actual
thrust while at cruising speed, but even if it were less than 20,000
pounds, it seems likely that the pilot, noticing the extra drag
of the cable, would simply advance the throttles a bit, easily breaking
the cable and continuing on his way. "
Well, David,
we did do our homework, honest we did, but the dog ate it!
For the record,
we are not the folks who first suggested that a pencil thickness
of spider dragline could stop a 747. It seems to be one of those
oft-repeated ideas of which the source is hard to discover. It sounded
good to us - after all a single strand (measuring less than 1/200
mm) of spider web can stop a 90 mg bee flying 15 mph in mid-flight.
If the high end estimates are right and spider silk is five-times
as strong as steel but with elasticity in the 400% range, we have
no trouble imagining a thick, very stretchy cable that could snag
and slow the plane down.
But then, David's
analysis sounds good to us too.
Where we really
differ is with David's conclusion. We think that if a pilot encountered
a cable of spider web that was as thick as a pencil, he'd be too
busy screaming and hyperventilating at the sight of the 500-foot
long spider who spun it to ever think of advancing the throttles
a bit. Thanks for keeping us on our toes, David!
Weather
Check Quiz Question 3: Hurricane season ends with this month, and we're hoping it goes out quietly. October was an unusually quiet Atlantic hurricane month with no new storms. However, two October storms, Kyle and Lili, hung around for October and continued to do plenty of damage. Kyle will go down in the record books, in third place, for what dubious achievement? A. Kyle brought the third highest rainfall ever recorded for a tropical hurricane in Bermuda; B. Kyle caused the third highest damage by a tropical storm to the city of Jacksonville, FL; C. Kyle was the third longest-lived tropical cyclone recorded.
Fan-E-Mail!
Last year, Davis
Instruments became the official weather station of the Albuquerque
International Balloon Fiesta , and this year our stations continued
to provide weather data for the event. Randy Lefevre, AIBF Meteorologist,
wrote to tell us how effective the stations were.
"We used three
of your weather stations around the balloon field," Randy told us.
"We had a Vantage Pro providing a short text observation (see website),
a Weather Wizard III providing observations from another location,
and a wind vane/anemometer providing winds for our morning weather
briefings. Your instruments worked great." (Well, of course they
did, Randy!)
Brian Lubbert
sent us an email with further illuminations on the whereabouts of
the magnetic South Pole. He included a couple of links that show
just how "wandering" the magnetic poles are. One, a CNN
science story, says that the North Magnetic Pole is heading
away from its current location in Canada toward Alaska, and on to
Russia! The Woods Hole Marine Magnetism Group
website explains how the Australian explorers David and Mawson, who were
part of the 1907-1909 Shakleton expedition, were the first to claim
the location of the magnetic South Pole, and how they were actually
off a bit. It gives the location of the magnetic South Pole in 1990
at 64.9 deg S 138.9deg E, and the geomagnetic south pole in 1990
at 79.2 deg S 180.9 deg E.
Weather
Check Quiz Question 4: We all know that the spectacular light show near the north magnetic pole is called the aurora borealis. What is its south pole counterpart called? Would you get the best view right at the pole? When is the best time to see the lights?
Tech Tips: Daylight Savings Time & Your Vantage Pro
Gary Oldham,
having recently adjusted his clocks back to Standard Time, wrote
to suggest we explain just how his Vantage Pro handles the time
change. The good news is that your Vantage Pro console either automatically
makes the adjustment in North America, Europe and Australia (assuming
you have your time zone selected properly), or you can manually
adjust it. The not-so-good news is that the recent lost hour's data
goes off to wherever that hour of time went -- the cosmos or the
fifth dimension -- to be replaced by the "new hour's" data.
In automatic
mode, the console will jump from 1:59 AM to 3:00 AM in the spring
and fall back from 1:59 AM to 1:00 AM in the fall. The dates on
which this occurs are based on your location (which you indicate
by your time zone in the console). If you don't live in the areas
mentioned above or your area doesn't observe daylight savings, then
you can choose manual mode.
If you observe
daylight savings time, but not in the areas mentioned above, then
you must manually switch Daylight Savings Time on or off at the
appropriate time. If you do not observe daylight savings time in
your area, then you simply leave the unit in manual and off mode
all the time. This includes most of Indiana and Arizona, all of
Saskatchewan, Hawaii, Western Australia and Northern Territory,
and Queensland.
What happens
if the unit is not set properly? Mainly, your sunrise and sunset
calculations will be off. Also, if you have a solar radiation sensor,
your ET and THSW Index calculations may be off. The unit calculates
the position of the sun in the sky to determine whether the amount
of solar radiation it is receiving is the maximum possible amount.
This helps it estimate sky cover which can then determine the affects
of solar radiation on evapotranspiration and comfort. Less importantly,
your moon phase changes may be off by an hour. Also, the highs and
lows the Vantage Pro logs could also be off by an hour.
Weather
Check Quiz Question 5: What famous American first thought
up Daylight Savings Time?
More
Weather World 'Round Sites
Our Weather World
'Round page is growing by leaps and bounds. In the past few months,
we've added a whole bevy of new URLs including Tierra
Del Fuego, Argentina; Guaynabo,
Puerto Rico; and about 20 new United States sites like favorite
storm locales of Wichita,
and Atlanta,
picturesque Strawberry, CA,
and Huntington,
in the Green Mountains of Vermont. We've now got representatives
of beastly cold with Savage,
MN,and the blithely temperate with San
Louis Obispo, CA.
Our current
favorite site is not a new one, but a revised one. The site for
West Paterson,
NJ, has a way-cool virtual Vantage Pro console created by John
Norman. You just must check them all out at Weather
World 'Round.
Honey Bees are Sweet on their Davis Weather Station
Carol Clement
has one of the best protected Davis Weather Monitor II weather stations
around. Not only is it surrounded by an electric fence, it is also
guarded by thousands of buzzing bees.
The bees, we
think, are right to be protective because the station allows Carol
to provide them with everything from proper ventilation in the summer
to "bee candy" meals when cold winter days overstay their welcome.
Carol's bees share Heather Ridge Farm, high on a mountain top in
Preston Hollow, New York - two hours and another world away from
New York City. It's a place where the seasons are intense and short,
and where knowing what the weather is doing is vital.
Carol Clement's weather station has a place of honor in her bee
community.
As a beekeeper,
Carol's role is to do all she can to save the bees work and stress,
so that they are free to visit the heather, wild thyme and apple
blossoms and produce lots of Carol's special heather honey. Carol
watches her bees closely, always aware of the dangers of a frosty
night or a hot afternoon, an infestation of mites, a disease epidemic,
and - bears! (The electric fence is usually enough to keep the bears
from knocking over the hives in search of honey, but sometimes the
bears get hungry enough to endure a little shock for a lot of sweetness.)
A beekeeper has to understand bees and where they live, and to that
means she has to understand the local weather - current conditions
as well as weather trends.
Honey bees,
Carol assured us, are naturally gentle creatures. Stinging costs
them their lives, and is not something they do without provocation.
"But," she added,
"bees don't like weather change. If the weather is going to change,
they can get very cranky and I try to avoid working with them when
they are cranky."
To bees, a change
in the weather might mean that giant raindrops will pelt them, making
it impossible to fly. It might bring winds that make flying dangerously
difficult. A drop in temperature might mean that the blossoms they've
been working will stop blooming, wreaking havoc with the honey production
schedule. No wonder they get cranky and head back to the hive and
show little patience for a human moving things around in there.
Carol's bees
are just part of Heather Ridge Farm's 160 acres of vibrant ecology.
They go hand in hand with the alpine meadow flowers, the heirloom
apple trees (with some "mother trees" over 80 years old), the wild
thyme and the bountiful heather that Carol loves. And of course,
there is no part of that environment more important than the weather.
The farm, which sits at 2,000 feet, has intense spring growing seasons,
and cold winters, both aspects that her bees' more southern and
western cousins don't have to contend with.
Beekeeping is
a year-round activity. Around this time of year, the bees are looking
forward to a long, lean winter. To save food, the few drones, who
are the minority male population of the hive, are kicked out to
die once their work in mating is done. In the winter, temperature
takes on extra importance. The bees settle into a not-quite-hibernating
mode, surrounding the queen in a ball, and using their wings to
create warmth, moving constantly from the queen to the outside of
the ball. Carol keeps a close eye on the temperature, but avoids
opening the hive in the wintertime. Although Carol leaves the hive
with about 80 pounds of honey, a winter that goes a week or two
longer than expected can mean starvation unless she provides the
bees with food. Occasionally, when a winter day is warm and sunny,
Carol watches to see if the bees come out for a "cleansing" flight
- a sign that the hive is healthy.
In the spring
time, everyone, bees and beekeepers alike, get very busy. The eggs
laid over the winter hatch and the bees head out to work whatever
plants are flowering. Carol must check the hives at least once a
week to make sure that the industrious bees have not overcrowded
their hive with honey. And she watches her weather station for signs
of rain, cold snaps, and weather changes to decide when to work
with the bees and when to leave them alone.
As summer slows
down the blooms, Carol's bees slow down a bit too. She must watch
the temperature carefully, as a hot day can melt the wax and make
the hives uninhabitably hot and humid. The bees use their wings
to cool the hive, and Carol's job is to make sure there is plenty
of ventilation and protection from the heat.
Carol credits
the bees with making her a better teacher and hiking guide. They
have made her more aware of everything from plant identification
to knowing when a storm is coming. She is passing on her bee knowledge
by maintaining a demonstration hive on a mountain-top arboretum
where she teaches workshops on beekeeping.
"The bees are
fascinating." Carol said. "They have taught me to pay attention
to the weather, to the seasons and the plants. I can tell what's
in bloom from the pollen they bring back to the hives. I can watch
the bees and link up the signs they give me with what's going on
the mountains."
"Following the
longer term weather trends is also very important to beekeeping,"
she added. "Comparing the average temperatures from month to month,
winter to winter is important for planning as well as for taking
immediate action. The files on my computer make it so easy!"
From her mountain-top
farm, Carol can look out over a valley to the next mountain top.
She can literally see weather approaching. Her vantage point, her
deep bond with nature, and her Davis Weather Station have made her
a favorite Weather Watcher for the local television station.
When she's not
watching the weather, rearranging the hives, grafting apple trees,
guiding hikers, or teaching future beekeepers the art, Carol and
her husband offer their apples and their thick heather honey and
beeswax products for sale at local farmers markets and in the village
shops. (Lucky Davis Weather Club members can reach her via email!
"I ship," Carol said, reminding us that Preston Hollow is not quite
outside of civilization. You can write her at HeatherRidgeFarm@aol.com.
Weather
Check Quiz Question 6: Just how many knees does a bee
have? And where did that term come from anyway?
You're Brilliant! Answers to Quiz Questions
Question
1:
Santa is losing it. Sunrise won't happen at the North Pole until
March 20. (On the 18th of March, the sun will sit on the horizon,
but it won't fully rise until the equinox.)
Question
2: You save the day by putting the nix on the outdoor party.
Being the weather guru you are, you predict precipitation within
the next 15 - 20 hours. Your spouse is mightily impressed. You hide
your Davis Quick Reference Weather Forecasting Cards in your sock
drawer.
Question
3: Kyle will go down in the weather history books for its tenacity,
having lasted for 22 days during which it weakened and strengthened
to a tropical storm four times. The only tropical cyclones that
were longer-lived were Ginger of 1971 and Inga of 1969. Both Kyle
and Lili were killers, with Kyle causing 85 deaths and Lili taking
145 lives. Lili also did $700,000 in damage in the US. (Source:
National Hurricane Service, Miami, FL.)
Question
4: The glowing Northern and Southern Lights are formed by solar
wind, fired off from the sun during solar storms, particles of which
are captured by the earth's magnetic field. The particles follow
the earth's magnetic fields, coming down near the magnetic poles
where the magnetic field lines disappear into the earth. (For a
much more thorough and understandable explanation check out the
Alaska
Science website or the
Poker Flat Research Range site.)
The Southern Lights are called aurora australis. The best place
to see the lights is in a ring shaped region near, but not at the
poles. Specifically, for best viewing of the Northern Lights, head
for Fairbanks, Alaska, near the equinox in March or late September-early
October. You could also try eastern Canada, Iceland, Scotland, and
Scandinavia.
Question
5: None other than Benjamin Franklin, who, while living in Paris
in 1784, wrote a very funny letter to the editors of The Journal of Paris, in which
he said he had "accidentally" discovered that the sun
actually came up before noon, and that Parisians would do well to
take advantage of this free light instead of burning expensive candles
all night. He suggested that shuttered windows be taxed and that
church bells should ring and canons be fired at sunrise to get the
sluggards of Paris out of bed. You can read the letter on the
Institute for Dynamic Educational Advancement (IDEA) website.
Question
6: If the knee is defined as the joint between the thigh and
the leg, then bees have six, of course. There's a terrific visual
of bee anatomy by PBS's
Nature. (If you define knee as the joint between the human
thigh and leg, then they have not a one.)
Phrase Finder claims that "the bee's knees" is an
allusion to the fact that great, high quality pollen is carried
back to the hive on sacs on the bee's legs. Personally, we like
the entry on that site's discussion board that implies that phrase
is just one of many expressions for "great" that came
up in the fun 20's, such as the elephant's arches, the clam's garters,
and the gnat's elbows. These came from a book called Listening
to America: An Illustrated History of Words and Phrases from Our
Lively and Splendid Past by Stuart Berg Flexner.
Who You Gonna Call?
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, you’ll find links for catalog requests
on our web site at http://www.davisnet.com/contact/catalog.asp
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-News. Member participation is what keeps the E-News alive
and kicking.
Well, that’s
it for this edition. You’ll be hearing from us again next month!
Vantage Pro,
Weather Monitor, Weather Wizard, WeatherLink, Weather Envoy, Weather
Echo and Weather Echo Plus, EZ Mount Gro Weather, EZ Mount EnviroMonitor,
EZ Mount Health EnviroMonitor, and Perception are trademarks of
Davis Instruments Corp
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