Download Meteorology - The Federation of Galaxy Explorers

Meteorology
GENERAL
Hello. This Mission will familiarize the Mission Team members with meteorology to
develop a basic understanding of weather observation and forecasting. We expect to expand
the terrestrial and space knowledge of all Galaxy Explorers in order to enhance their
understanding of planetary science.
DISCUSSION
“Meteorology is the study or science of the atmosphere. The atmosphere is composed of
oxygen and other gases. We know that oxygen is necessary for life. We could not live long
with out it. Water vapor is one of the other gases in the atmosphere. If the conditions are
right, we see the water vapor in the form of clouds. When there is enough water vapor in the
atmosphere and it is cool enough, it falls down in the form of rain or snow. We call this
weather. We like to know when it is going to rain or snow so we like to have people do
“weather forecasting”. People have gotten pretty good at this and they predict the weather a
few days ahead. Let’s look at some of the ways to forecast the weather.
You can tell a lot about the weather by looking at the clouds. You have all seen the white
puffy clouds that are all puffy like these (Slide 2). When they are small like this they
indicate fair weather so have a nice day. When cumulus clouds get really big and tall they
turn into thunderstorms (Slide 3) so go inside. Sometimes you see clouds like these (Slide 4)
that look like a flock of sheep. These are pretty to look at, but they don’t tell you much about
the weather. Another type of cloud that makes spectacular sunsets is cirrus clouds (Slide 5).
These precede warm fronts that we will talk about later. Often rain will follow a day or two
later. Stratus clouds (Slide 6) are low clouds that are associated with drizzle or fog. Clouds
are pretty to look at (Slide 7), but they are rather unreliable indicators of what the weather
will be in the future.
Weather forecasters use information from weather satellites, weather station measurements
and weather balloons to predict the weather much more accurately. They put this
information in computers and get products like this weather map (Slide 8). This map may
look complicated, but it is really pretty simple. Big patches of cold air come down across our
country from Canada. The leading edge of the cold air mass, called a “cold front” is
indicated by the blue line with the triangles on it. Since the cold air is heavier, it causes
higher pressures as indicated by the big blue “H” on the map. Warm fronts are indicated by
the red lines that have half circles on them. Sometimes the air doesn’t know which way to go
and it forms a stationary front indicated by the alternating red and blue lines. The purple line
indicates an occluded front where a cold and warm front has combined. So what is the big
deal with fronts anyway? Well that is where the bad weather is. A cold front is associated
with showers and thunder storms. Warm fronts usually bring steady rain. You can see that
the clouds lie along the fronts on this weather map.
Of course, the weather forecasters have a lot more information about the temperatures,
pressures and water vapor in the atmosphere so they are able to predict weather fairly
accurately for your specific area. They can see where it is raining from satellite pictures like
this (Slide 10). Notice how the small storm system over Texas gets bigger and moves up
toward Virginia as time passes. Other weather forecast products include temperature (Slide
11). As you would expect the purple over Canada indicates that it is cold up there and the
orange indicates that is warm in Mexico and Texas.
There is much more to meteorology. Some people have spent a lot time studying snow. A
man named Wilson A. Bentley photographed snowflakes about 75 years ago (Slide 12).
One way people describe the weather is using the Beaufort Scale. The Beaufort Scale is a
system of recording wind velocity (speed) devised in 1806 by Francis Beaufort. Actually
this scale is a list of numbers from zero to twelve. Each number describes how hard the wind
is blowing.
(Mission Team Leader Note) List the scale and describe.
Beaufort Speed
Scale
mph
0
below 1
1
1-3
2
4-7
3
8 - 12
4
13 -18
5
19 - 24
6
25 - 31
7
32 - 38
8
39 - 46
9
47 - 54
Effects on Land
Smoke rises straight up; tree leaves
without perceptible motion
Rising smoke drifts; tree leaves barely
move
Effects on Water
Sea flat and mirror like
Ripples without foam on
crests appear
Small wavelets form, with
Leaves rustle slightly; wind felt on face short but pronounced crests
that do not break
Large wavelets with breaking
Leaves and twigs move; loose paper
crests form; occasional white
and dust raised from ground
foam crests
Small branches move; wind raises dust Small waves form; white foam
and paper
at crests more frequent
Moderate waves occur, with
Small trees sway and large branches in
foaming crests and possible
motion; dust clouds raised
spray
Large branches move continuously;
Large waves form, with
wind whistles; umbrellas difficult to use extensive white foam crests
Sea heaps; white foam blows
Whole trees in motion; walking difficult in streaks from breaking
waves
Moderately high waves form,
Tree twigs break; walking progress
well-marked streaks of foam
slow
blow with wind
Slight structural damage
High waves form, with dense
10
55 - 63
Exposed trees uprooted; heavy
structural damage
11
64 - 72
Widespread damage
12
above 73
Severe damage and destruction
streaks of foam
Very high waves with long
overhanging crests occur;
great patches of foam blows in
dense white streaks
Exceptionally high waves
form; sea covered with long
white patches of foam; wave
crests blown into froth
Exceptionally high waves
form; air filled with foam and
spray; sea completely white
Activity 1. Build a Beaufort Scale box. This box will determine wind speed. Each Mission
Team Member will need the following materials:
1. A card board box
2. A strait piece of coat hanger wire about 8 inches long
3. Self adhesive shelf paper (Optional)
4. A sheet of aluminum foil
5. Tape
1. Cut off both ends of the box. Use tape to reinforce any pieces that get loose when the box
is cut.
2. Cover the inside and outside of the box with self-adhesive shelf paper.
3. Cut a strait piece of wire about 8 inches long from the coat hanger.
4. Poke the piece of wire into the side of the box1/2 inch in from the open end and ½ inch
below the top. Push the wire strait across the opening and out the other side. Make sure the
second hole is directly opposite the first. Bend the ends of the wire down.
5. Slide one of the 6-inch edges of the aluminum foil over the wire and make a fold about 1
inch deep all along the folded edge. Tape the fold with cellophane tape so that the foil hangs
down like a curtain. Be sure the curtain can move freely on its rod.
6. Push on the bottom of the curtain so that you can see the curved path that the bottom of the
curtain follows as it swings inward. Cut a curving slot about 1 inch wide the goes along the
side of the box from the bottom to the top following the path of the curtain.
7. Write the number 0-12 on the side of the box over the curving slot.
8. Finish off the edges of the box with plastic tape.
Box
Wire
Curving slot
Beaufort Scale
Curtain
Activity 2
You may want to have one jar for several Mission Team Members. This activity is to
demonstrate to the students the direct affects of pressure and temperature on cloud formation.
OBJECTIVES:
1. To demonstrate the principles involved in cloud formation.
2. Transfer this information to weather maps to predict cloud formation and clearing.
3. Introduce the term nuclei, necessary for attachment to form clouds
RESOURCES/MATERIALS:
1. Wide mouth gallon pickle jar
2. Heavy duty clear plastic bag
3. Rubber bands or masking tape
PROCEDURES:
1. Place about 20 ml of water in a wide mouth gallon pickle jar
2. Place a lit match into the jar.
3. Quickly place a heavy duty clear plastic bag over the mouth of the jar and secure a
firm seal by placing a rubber band/masking tape around the top of the jar.
4. Push the bag into the jar quickly, then pull the bag out. Observe!
TYING IT ALL TOGETHER:
This activity illustrates how humidity, temperature, and air pressure influence the formation
of clouds. The water produces high humidity in the jar and the smoke introduced by the
match provides nuclei on which the water vapor can condense. As the bag is pushed into the
jar pressure and temperature in the jar increases causing the jar to clear. Upon pulling the bag
out, pressure and temperature decrease allowing water vapor to condense and produce a
"cloud" inside the jar.
Questions for further inquiry:
1. Why are smoke and water added to the jar? (provide moisture and nuclei for cloud
formation)
2. What does pushing and pulling on the bag do to the jar? (increases/decreases
pressure)
3. How would warming or cooling the jar effect the observations? (decrease/increase
cloud information)