WEBVTT

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DAISY: NASA spends lots of time
and resources studying the
weather.

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And winter weather is
particularly important.

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That's why NASA sponsors the
History of Winter workshop for
teachers...

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We'll take you to a frozen Lake
Placid to learn about

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the tools that measure the
conditions of our coldest
season...

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Next on Real World.

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? [music] ?

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Winter conditions here on earth
are very important to

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NASA Scientists and engineers.

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The agency's aeronautics
mission relies on data

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gathered during the coldest
part of the year.

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They use it to develop systems
that will allow

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planes to fly better and safer
in winter conditions...

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The exploration mission studies
winter conditions, too.

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Data related to harsh
winter-like conditions here,

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give scientists perspective
about other places in the
universe...

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like the Moon or Mars...

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ALLEN LUNSFORD: Now that we're
discovering more
closely,

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ice on other planets, it's
important to understand their
properties.

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DAISY: Allen Lunsford is a NASA
computer scientist

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and History of Winter
technologist.

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ALLEN: Not only of natural ice,
on earth, but ice that

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forms in other conditions that
you don't find on earth.

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Higher pressures, lower
pressures, different

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temperature regimes, the same
concepts that we learn

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here at H.O.W. are the concepts
that are used by

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scientists to study ice all
over the solar system

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DAISY: Teachers come to Lake
Placid, New York and become

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scientists for a week, rolling
their sleeves up and

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taking a hands on approach to
understanding winter.

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One of the things these
teacher-slash-scientists do

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is learn how to measure abiotic
conditions of Winter.

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Abiotic conditions are all the
non-living elements of an

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ecosystem, like air and soil,
and snow and ice.

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At Lake Placid, they use lots
of tools for measuring these
conditions.

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One of the simplest tools to
measure ice is called a

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thermochron, and teachers at
History of Winter

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get a lot of use out of this
tool.

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ALLEN: A thermchron is a little
data logger.

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It has a clock and a little
computer and some memory, so

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it keeps track of time and
temperature.

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It's really kind of small,
compact and rugged.

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So you can connect it to a
computer and program it to

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record the temperature every
minute, every two minutes,
whatever you like.

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It's rugged enough that you can
bury it in the sand or

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put it under water or put it in
a snow pack, and later

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retrieve it, connect it to the
computer again, download

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the data and then analyze the
temperature history

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that the thermachron
experienced.

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DAISY: Here's an experiment you
can do with a thermochron...

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Drop it in a glass of water...
put the glass in the freezer,
and let it freeze.

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Then take it out of the
freezer,

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and let it melt.

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This is going to talk a little
while.

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Once it's back to room
temperature, pull the

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thermochron out and check the
data on a computer.

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ALLEN: That's a great
experiment, to show them the

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concept of latent heat, where
it'll start warm and come

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down to the freezing point of
water, zero degrees and then

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it will stay zero for a long
time, and as all the water in

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that cup freezes, and then once
it's all frozen,

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only then does the ice start to
get colder and it

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will get as cold as the
freezer. When you take it out
of the freezer,

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it'll get warmer, really
quickly, right up to zero,

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and then it will stay zero for
a long time until all

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that ice has melted and then it
will get room temperature.

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Those little areas there, where
it maintains

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temperature, even though it's
absorbing heat or

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releasing is that latent heat
concept.

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DAISY: Another Abiotic
condition that scientists

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want to learn more about is
snow. And there are lots of

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ways they measure snow at HOW.

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TOM ALENA: You actually use
what is called a snowboard.

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DAISY: Tom Alena is a
meteorologist at Talcott
Mountain Science Center.

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TOM: Not a fancy thing you go
downhill snowboarding in.

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It's a piece of plywood, maybe
2x2. You place it on

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the surface of the snow before
the storm.

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And every six hours or so you
measure the accumulation on
that board.

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DAISY: But then you have to
reset the board. Cleaning

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the accumulated snow off. This
is very important.

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TOM: The more snow that's on
it, it's going to compact the

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snow so if you went two days
after the storm, and just

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measured the one measurement,
you might have a little less

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snow than what really did fall.

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DAISY: It's also important to
measure the density of the
snow.

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TOM: We can calculate using
those snow tubes, putting

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them on a weight, a certain
known volume, with a weight,

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grams per cubic centimeter, and
we can get densities.

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DAISY: Scientists use this
information to determine the

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snow water equivalent.

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This is the amount of water
contained within a snow pack.

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TOM: A layer of snow... how
much water would be if you
melted that down.

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A good start is 10:1. So ten
inches of snow would melt

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down to a one inch layer of
water.

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Cold dry fluffy snow... that
could be 2,0 even 30 to One.

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The very heavy stuff, sleet is
almost 2:1, and ice of

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course, would be a one to one.

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DAISY: More data about snow
density can be recorded

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simply by observing the snow
flakes.

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TOM: If they come out of the
cloud base at that point, they
are beautiful.

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They're like little glass
sculptures. However, if they

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continue going through a lot of
cloud, the cloud droplets stick
to it.

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It's called riming. Those
crystals tend to have a lower
snow ratio.

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Moisture and temperature, very
important variables in the
cloud.

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DAISY: There are a lot of very
practical reasons to study snow
density.

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TOM: It's very important in
watershed resources.

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In the western United States
where the Sierra Nevada

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harbor the entire summer water
supply for much of the big
cities.

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People there, doing core
samples all the time in the

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snow to look, how deep? How is
its density?

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And calculate how much water is
up there for the spring and
early summer melt.

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DAISY: Studying snow density
can also help predict avalanche
dangers.

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When snow of different
densities get's layered,

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one on top of the other, layers
tend to slip.

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Especially when you get a layer
of low density icy snow.

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TOM: That ice layer can really
act as a slippery

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surface for a brand new snow
fall.

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That's usually there where
you'd expect slippage.

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DAISY: So now you see why it's
important to study about these
topics.

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But from NASA's perspective,
the best reason to bring

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these teachers up here is so
they bring back great ideas

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to the classroom, teaching kids
to grow up thinking like
scientists.

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And those kids will be the ones
who lead NASA forward

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through the next generation,
and continue exploring our

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world and the worlds beyond.

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? [music] ?

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..