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ArkLaTex Meteorological Inquiries
ArkLaTex
Meteorological Inquiries |
If you ever
wondered why the sky was blue or any other weather phenomena, then we
invite you to submit
your questions.
Questions submitted will be answered and then selected ones will be posted
on this page.
We look forward to your questions!
| How
is the inner circumference of a rain guage determined?
|
There are a couple of assumptions. The first assumption
is that water is conserved going from one cylinder to the another.
The second assumption is that the rain gauge measures to the nearest
hundreadth (0.01).
The formula converting rain going from one cylinder size to another
is:
Volume = (pi)(r2)(height
of the water), where pi = 3.14159, r
= radius of cylinder
For example: We want to know the diameter of the inner cylinder
of an 8-in standard rain guage if we want to measure every 0.01.
Assuming one inch of rain fell into the rain gauge. The height/depth
of rain going into the big cylinder would be 1 inch, but in the
inner cylinder the height/depth would be 10 inches in the small
tube to get 0.01 accuracy.
(pi)(radius of outer
cylinder)2(depth of water) = (pi)(radius
of inner cylinder)2(depth of water)
3.14159(42)(1 inch depth) = 3.14159(r2)(10
inches depth)
50.26 = 31.41(r2)
50.26/31.41 = r2
1.6 = r2
1.26 inches = radius of the inner cylinder
Diameter = r2 = 1.26 x 2 = 2.52 inches diameter of
inner cylinder.
So an official 8-in
rain guage from the National Weather Service has an inner cylinder
diameter of 2.52 inches. So the measuring stick that is 24 inches
long measures 2.4 inches of rain.
Bill Murrell
Meteorologist
|
| Why
do clouds appear to float?
|
| Clouds appear to float for two main reasons.
The terminal or downward velocity of the tiny water droplets is
very slow and when clouds are present there is usually some upward
velocity that offsets the downward motion of the tiny water droplets.
Bill Murrell
Meteorologist
|
| WHY
IS THE SKY BLUE? |
Short
Answer:
Blue and Violet are scattered the most in the atmosphere compared
to the rest of the colors produced from the Sun. Violet is scattered
the most, but our eyes are more sensitive to blue. Thus, we see
a blue sky.
Longer Answer:
The sun emits visible light. The visible light is made up of different
colors from violet (shortest wavelength) to red (longest wavelength).
The atmosphere is made of tiny molecules (nitrogen, oxygen, dust,
etc.) which allows the most scattering to occur with the shortest
wavelengths, which for light are violet and blue. This kind of scattering
is called Rayleigh scattering. Rayleigh scattering by definition
is "a scattering process produced by spherical particles whose
radii are smaller than about one-tenth the wavelength of the scattered
radiation" (Glossary of Meteorology). So as light encounters
atmospheric particles, the violet and blue colors of the color spectrum
is scattered much more than the colors that have a longer wavelength
(red). Since violet has the shortest wavelength, the sky should
be violet, but because our eyes are more sensitive to blue we see
a blue sky.
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