2. Grade 7 Vocabulary List (Inquiry on Weather)
Humidity
Dew Point
isotherm
Meteorologist
El Nino
Weather
Precipitation
Atmosphere
Troposphere
Ionosphere
Ozone
Ultraviolet
Conduction
Convection
Hydrosphere
Condensation
Front (weather)
Tornado
Hurricane
Blizzard
Isobar
Climate
Polar
Temperate
Greenhouse
Deforestation
** Need to write for each word:
1. Definition
2. Your own sentence
3. ______________________________________
(Summary Note for Chapter 16, Section 1, pg. 452-461)
Weather is the state of atmosphere at a specific time and place. In short, it describes conditions
of three things:
1. ________________ (ex. air pressure, wind)
2. ______________________ (ex. water moisture in the air)
3. __________________________ (Ex. temperature)
However, the Sun is the biggest factor in ultimately establishing the weather because it
provides almost all of the Earth’s energy. For example, energy from the sun affects the water
moisture through evaporation. Differences in temperature between 2 regions of the earth can
cause wind currents and more.
Here is some more general information about the major defining conditions of weather:
1. _______________________________________-
Air consists of molecules that are always moving in a random motion. Air temperature is a
measure of how _____________________ air molecules are moving. When heat from the
sun (or other energy) hits air molecules, they move faster and the temperature goes up. When
heat is removed, they move slower and the temperature goes down.
2. _____________________________-
The wind refers to the _______________________________. There are many ways air
movement occurs. The most basic one is simply the rising and falling of air. When air is heated,
it become less dense and moves up. On the other hand, when air is cooled, it becomes more
dense and moves down. We (and also instruments) can feel this rising or falling movement of air
as the wind. To more specific, different areas of air will have different densities depending on
their temperature. This creates higher and lower areas of air pressure. Air will travel from airs of
high pressure to low pressure allowing wind to move in any direction and at different speeds.
3. ______________________________-
Energy from the sun can cause water to evaporate into water vapor (gas). The
____________________________________ in the air is known as humidity. When there is
greater sunlight (ie. when it is hotter), more water evaporates and the humidity increases. On
the other hand, when there is less sunlight (ie. when it is cooler), water vapor changes back into
water through the process known as condensation.
4. _______________________________-
The dew point is related to humidity. More specifically, it refers to the specific temperature at
which water vapor changes (ie. _______________________) back into water for a particular
location. Thus, when you see water form out of the air on some cooled object, the present
temperature at the place where the water forms is called the dew point.
4. Also note: if the a place’s temperature drops too quickly (to around zero), the water vapor will
change into ice instead of water. This type of ice is called _______________________
Other Important Features of Weather
A. _________________________-
If fact, clouds are formed in the same way that dew forms except it happens high up in the sky.
The temperature drops low enough that water vapor in some part of the sky changes into water.
But these water droplets form around little particles in the air such as dust and are prevented
from falling. Instead, they all get stuck together to make a cloud.
There are also different ways the water droplets can get stuck together because the amount of
dust but also because of differences in temperature, pressures and the amount of water vapor.
As a result, different kinds of clouds can be formed. In general, we classify clouds by their shape
and height.
_____________________ clouds usually form at low altitudes. They form as smooth sheets in
the sky or even just above the ground to make fog. ___________________clouds form at very
high altitudes and are very puffy and white. ____________________ clouds are very curly or
fibrous clouds. They look like feathers. Eventually, some clouds can accumulate enough drops
of water such that they become too heavy to be held up by nearby particles in the air. They will
soon produce rain or snow. These clouds often include the word “nimbus” in their naming.
B. __________________________-
When clouds get too heavy and their water particles begin to fall, we call the falling water:
precipitation. The type of water particles can vary depending on the air temperature. There are
four types: _______________ (just water droplets), _____________ (thin),
______________(thicker ice in the form of pellets) and ___________________(big lumps of
ice). As well, the size of the water particles can also vary depending on the wind and the
temperature. Updrafts keep the water droplets in the sky longer so they can combine with other
drops and grow bigger before falling. If the temperature goes up enough, water droplets may
evaporate again before even falling.
5. SUMMARY – Organizer Handout
(for Chapter 15, Section 1)
Step 1: Read one time. * Take notes too if you want! Reading Notes
Step 2:
Write the Main Idea (1-2 sentences) –
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
Step 3: Write the supporting ideas. Write in the small boxes first!
Step 4: Write the supporting details. Write in the bigger boxes later!
Supporting Idea 1 (1-2 sentences)
Supporting Details 1 (1+ sentences)
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
Supporting Idea 2 (1-2 sentences)
Supporting Details 2 (1+ sentences)
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
_
8. Earth’s Atmosphere
(Chapter 15 , Section 1)
In order to understand weather better, you should first understand “where” weather occurs. It
normally takes place in Earth’s atmosphere. Our atmosphere is a thin layer of air that serves
as a protective covering around the whole planet. In addition to things happening in the
atmosphere, it also plays an important function in regulating the amount of sunlight that
comes in or remains after.
The Makeup-
The earth’s atmosphere is a mixture of gases, solids and liquids that all surround the
planet from the Earth’s surface right up to outer space. Gases include mostly nitrogen
(78 %) , oxygen (21 %) and then there is a very small amount (1%) of other gases such as
neon and ozone. Solids include small, solid particles such as dust, salt and pollen. Liquids
include water droplets. And all of the gases, solids and an liquids are constantly moving and
can change. So for example, droplets of water from a volcano erupting could travel thousands
of kilometers to other areas of the Earth.
People even believe that Earth’s atmosphere was very different a long time and changed
slowly over time to what it is today. A long time ago, the atmosphere still had a lot of nitrogen
but had more carbon dioxide and little oxygen. But Earth’s early organisms released oxygen
in air. This oxygen later formed the ozone layer that protects now many living things from the
sun’s harmful rays. Then, more plants could survive and more oxygen was released into the air.
Layers of the Atmosphere-
The earth’s atmosphere has layers. There are five in total as follows:
Trophosphere – this is the lowest layer of the atmosphere. It is from 0 – 10 km and it contains
almost all the water vapour (99 %) and most of the gases in the atmosphere ( 75 %)
Stratosphere- this layer is about 10 -50 km high. It contains higher level of a gas called ozone.
The ozone helps to protect the earth from harmful rays.
** The troposphere and the stratosphere together make up the higher atmosphere
Mesophere – it extends from the top of the stratosphere to about 85 km up. Inside it is a layer
of electrically charged particles called the ionsphere. Radiowaves travel through the
ionsphere. As well, sunlight can interact with the ionsphere causing its particles to even absorb
AM radio waves. This is why AM is worse in the day light, because it gets absorbed better rather
than being reflecting off the ionosphere
Thermosphere – it is found between 85 km and 500 km above. Here, you can also find the
ionsphere. As well, this layer of the Earth is actually very warm and is the thickest layer.
Exosphere – the exosphere is the last layer of Earth to open space. There are few molecules
here. So flying objects cannot use friction but must rely on bursts of rocket thrusters to move
about. Space shuttles orbit the Earth in the exosphere.
9. Atmospheric Pressure –
It is also important to understand that all the gases in the atmosphere have mass (similar to
weight). So they get pulled toward the Earth’s surface by gravity. You feel this pulling of air
molecules as pressure. As well, the weight of all the gases higher above presses down the air
below and makes its molecules pack closer together. As a result, the air closer to the ground is
more dense and is pulled more by gravity. The pressure is higher here. On the other hand,
the higher up gases are not compacted and so their molecules are spread out more. The
pressure is lower in these higher up laces. People can only breathe well in high pressure
places because more oxygen gets pushed together enough for them to breath.
Temperature –
The various layers of the atmosphere are also at different temperatures. This is because they
have different amounts of gases. When the sun passes through a layer, it gets absorb more
easily with some kinds of gases or amounts of gases than others. So some layers absorb more
sun and are warmer while others absorb less sun and are cooler.
As well, the Earth is very hot at its core and even the surface of the Earth gives off heat. As a
result, the higher up you go, the less heat you can receive from the Earth’s surface.
So the combinations of the Earth’s surface and abortion of the sun produce special effects on
the temperature for each layer of the atmosphere. (see. Figure 8)
The Ozone Layer-
The ozone layer in the stratosphere is made up of oxygen. The oxygen atoms however
arrange themselves in groups of three to make up ozone molecules. Then they all stick
together to make the ozone layer. This layer is then able to shield certain types of sunlight
including a lot of ultraviolet radiation. This is important because too much ultraviolet radiation
can kill living things by causing cancer.
Unfortunately, pollution may be destroying the ozone layer. Harmful pollutants such as CFCs
(chlorfluorocarbons) can react with ozone molecules to make new molecules that do not absorb
ultraviolet radiation well. Such reactions are believed to occur in certain places only to create
holes in the ozone layer such as the one located above Antartica.
10. _____________________________________________
(Summary Note for Chapter 15, Section 2)
Part 1 – _________________________________
Most of the energy on Earth comes ultimately from the sun. How the sun provides energy to the
Earth occurs in a special way. (And it also results in various weather effects)
i) The flow of solar energy can occur in ______________ ways-
1. Some of the energy is ___________________ right back into space by either the
atmosphere itself (the many small particles) OR by the clouds in the atmosphere
OR by the Earth’s surface
(see figure 11 on page 435 )
2. Some of the energy is ___________________________________ itself
3. Some of the energy travels through the atmosphere and
___________________________ _______________________________
* Also Note! The amount of energy that gets absorbed is a very delicate matter. Just enough
energy gets let into the atmosphere to allow heat to be transferred and allow the various effects
on weather and to provide enough heat for life on Earth. If this amount were not controlled well,
too much light or not enough light entering the world would have deadly affects on the Earth.
(either it would be too cold and nothing would live or too much radiation would enter also killing
everything)
ii) __________________________ is produced in ______________________ as solar
energy travels through the atmosphere
1. __________________________– heat is generated from moving radiation waves
from the sun itself. The moving radiation waves come directly from the sun an
travel all the way to the atmosphere as form of energy called radiant energy
2. _______________________– First, the earth is warmed by radiation (heat) from
the Sun. But then, the surface of the earth transfer some of its heat back to the
atmosphere of the Earth. Basically, warmed particles of the earth are in contact
with air molecules. The transfer some of their heat energy which then causes the
air molecules to be warmed. These air particles than come into contact with other
air particles and pass heat energy to them. Eventually, more and more particles
get touched and heat is passed from one particle to the next. We call this kind of
transfer of heat: conduction
3. Convection- After the atmosphere is warmed by radiation from the sun or
convection from the Earth, certain molecules in the air can move from one area to
another and take their heat energy with them to warm new areas up. In general,
warmer air molecules rise up from lower altitudes to higher altitudes because of
differences in density. The passing of heat energy by the movement of heated
particles is called convection. (see figure 12)
11. Part 2 – ________________________________-
The Sun’s energy also causes water in the atmosphere to change regularly from a liquid to a
gas (ie. evaporation) and later from a gas to a liquid (ie. condensation). More specifically, these
changes occur as a constant cycle involving all waters of Earth that are known as the
hydrosphere.
Basically, the cycle is as follows:
1. Water evaporates from lakes, rivers and oceans and enters the earth’s atmosphere
2. Later, as it rises it cools and changes back into a liquid up in the sky. We can also say
the water condenses.
3. Often, condensed water particles will collide in the sky with each other and other particles
in the atmosphere. They get stuck together and stay up in the air by resting on other
particles. The collection of such water particles forms clouds.
4. The water droplets of the clouds get bigger and bigger as more water condenses.
Eventually, they fall to the ground as precipitation and eventually reach the lakes, rivers
and oceans to complete the cycle.
(see figure 13 on pg. 437)
12. _________________________________________
(Summary Note for Chapter 15, Section 3)
As mentioned briefly before, air movement is caused by the sun when it heats up different parts
of the Earth in different amounts. But there are other forces at work too that cause the wind to
move or affect how it moves (ex. affects the wind’s direction)
Most importantly, for ALL areas of the earth, there are 3 main causes of air movement.
1. ________________________- The heat from the sun warms the air molecules by its
radiation. When air molecules are warmed, they move about faster and faster. Eventually, they
cannot stay in one spot. So they move away from the heat further and further until they can cool
and relax again. When the air molecules, move away from the heat, wind occurs! (ie. There is
air movement!)
2. ___________________________-
Air density is the amount of air molecules in a given area of air. The more air molecules in an
area, the greater the density. Air molecules will move from a greater density area to a lower
density area. This is because the air molecules are always moving randomly around in any area
at any time. But in a dense area, many molecules will bump into each other and stay. But also
many other molecules will miss bumping and “fly away”. The movement of many air molecules
away from the area is enough to make wind! (ie. There is air movement!)
Later, the density gets low. Now not enough air molecules are together to move away together
to make a big enough force of wind (so you can’t naturally have a significant movement of air
from a low density to a higher density)
3.____________________________ –
Another air movement factor is Earth’s spin. The earth is constantly spinning around. (You know
it takes 1 day to make a complete turn). Air molecules normally move in a straight path in an
area at rest. However, moving area molecules will appear to curve when they are in a spinning
area. Because the whole area itself has started to spin, the target area moves away to the right
or left from where the air particles travel to. So to the target area, the air molecules appear to
have moved to the right or left. (Of course, it is really the target area that is curving and not the
air itself!) straight anymore)
The same happens when you are on a merry-go-around. If you are on a merry-go-round and
throw a ball something to a person straight across. Does the ball travel straight to him/her? No.
It will land to the left or right of him/her. Air molecules experience a similar situation!
_____________________________-
Because of the three factors described before, air movement can occur in various ways
(because of one factor or even a combination of multiple factors). So, is the air movement
random? NO. Actually, specific patterns of air movement get created by these factors depending
on the location of the Earth. The location affects these patterns because of the sun’s heat.
Different amounts of heat hit different parts of the Earth to cause different types of wind
movements called Global Wind Patterns. You can describe the general features of these world
wind patterns as follows:
__________________________- at the North and South Pole, density related air movement
occurs along with the coriolis effect.
--> It is colder at a pole so the air is very dense. (ie. there are many air particles crowed
together). It is warmer away from the pole (ie. it is less crowded). So air moves away from the
poles.
--> The earth is spinning. As a result, the air that moves away from the poles does not fly
straight across but instead flies at an angle to the left (north pole) or to the right (south pole).
13. ________________________- Near 30 degrees north and 30 degrees south latitude, heated air
movement occurs at large and also the coriolis effect
--> Here, air moves towards the poles because any area farther from the pole receives more
heat than an area closer to a pole. So this heat causes the air molecules to move away towards
the colder area (which is towards a pole)
--> The earth is spinning. As a result, the air that moves towards the poles does not fly straight
across but instead flies at an angle to the right (north pole) or to the left (south pole).
______________________- Near the equator, mostly density related air movement occurs
along with the coriolis effect.
--> Here, air begins to move towards the poles because it is colder in that direction BUT also the
region immediately away from the poles (the equator) has almost no air molecules because it is
so hot there. So, instead the air tends to move actually away from the poles in this area as it
travels from a more crowded area to a very non-crowded area the equator
--> The earth is spinning. As a result, the air that moves towards the poles does not fly straight
across but instead flies at an angle to the left (north pole) or to the right (south pole).
_______________________ – at the equator, mostly heated air movement occurs only. It is so
hot here, that most air molecules fly away (towards either pole) and make this area almost free
from any wind. So the air density or pressure is VERY low here.
** See Figure 17 on pg. 441
_________________________________-
The Global Wind Patterns are not the only types of wind systems. Other types can occur too
including:
_________________________- There are certain areas that are on the bolder of warmer air
near the equator and colder air near the poles. As a result, a special jet stream of wind occurs
from the colder air region to the warmer air region. Jets sometimes fly in the direction of the jet
stream to fly faster around the world or avoid go against it so that they don’t have to work as
hard.
_______________________________- Currents of air also form when water meets the land.
This is because the water is colder or warmer than the land and so air moves from the colder
area to the warmer area as density air movement. More specifically, in the day time, the land is
warmer than the sea so the wind blows from the land to the sea. (The air around the land is less
dense than the air around the sea). But at night, the sea is warmer than the land so the wind
blows from the sea to the land. (The air around the land is more dense than the air around the
sea.)
14.
15. ________________________________________________
(Chapter 16, Section 2)
In addition to there being a number of global wind effects like the Trade Winds and the Coriolis
Effect, various patterns of air movements, precipitation and other effects can happen at more
local regions within them. As well, these more specific air and water effects are constantly
changing and moving. We can refer to them as __________________________ and use
specific words to define their behaviors as follows:
________________________- the word air mass is used to describe how a body of air acts
within some more local region. Normally, the way an air mass develops is
______________________ upon its specific _____________________. For example, if there is
land below the air, the air is usually more dry than other air where there is water below it. The
temperature can also define the nature of an air mass. For instance, cold air masses blow from
the polar regions towards the middle while hotter air masses blow from the middle of the Earth
towards the poles.
And the air pressure changes within the world also cause _________________________.
Normally, when air moves from a high pressure area (air molecules are more dense or crowded)
to a low pressure area (air molecules are less dense or crowded), there will be more water
condensation and often even _______________________________. The air swirls a lot more
and rises up more and is called a ____________________. On the other hand, when air moves
from a low pressure area to a high pressure area, there will be less water condensation and
more sinking motions of air. As a result, the weather is usually more fair here and the air here is
called an __________________________.
See figure 9 on pg. 462 for some examples of air masses in North America.
___________________- Another way that specific weather effects occur is because of the
meeting of two or more different types of air masses. The place or boundary where they meet is
called a _______________. We can further divide these fronts into different types depending on
which meeting air mass is moving faster than the other one(s).
i) _______________________- With a cold front, cold air is moving faster towards warmer air
and it pushes under the warm air and causes the war air to greatly move upwards into the sky.
As a result, the warmer air gets cooled much quicker as it is pushed up and this can lead to
more rapid cloud formation and precipitation. In other words, thunderstorms often result at such
a front but for a short time. See figure 11, top left.
ii) ______________________ – With a warm front, warm air is moving faster towards colder air
and it slides more gently over the colder air and gently upwards. As a result, more condensation
and rain also occur and usually for a long period of time causing days of rain as the warm air
moves more slowly upward. See figure 11, top right.
iii) ___________________ – With an occluded front, colder air, cool air and warm air all meet in
one area. Here the colder air is moving the fastest and it again forces the warm air upwards
(like with the cold front). But there is also cooler air nearby so the warm air also gets pushed up
somewhat by the cool air too in another direction. See figure 11, bottom left.
16. iv) ___________________ - With a stationary front, cold air and warm air meet. Neither is
moving much faster than the other and there is like a showoff. Neither air mass can advance
over the other and they just push at each other for a good period of time. In the place where
they push as each other, a light wind and some precipitation can occur. See figure 11, bottom
right.
____________________- as mentioned above, in certain cases, (example air moving to low
pressure zones or with certain fronts meeting), more special weather effects can occur that
usually involve great precipitation and wind movement can be dangerous. We can all such more
violent weather behavior, severe weather. Some of them are described now below:
____________________- a thunderstorm usually occurs in warm, moist (wet) air masses or
between certain fronts. There are a number of features. First, it rains hard. This is because
warm air usually gets pushed up faster and higher forming big cumulonimbus clouds. And then
eventually water droplets condense and fall and even collide with other water droplets falling
into bigger, heavier and faster falling water. The sudden heavy rain can even cause dangerous
flash floods because rivers receive so much water that they spill over onto the land.
Second, the sinking water cools the air. This sinking cool air mixes with other warm air
that is still rising. As a result, ___________________ usually forms during a thunderstorm.
These winds can damage things too.
Third, _____________________ can result. As just explained, sinking cool air mixes with
rising warm air. Such movement can cause the forming clouds to have different electrical
charges at their ends. Then, current flows between the charged ends, creating lightning.
Further, lightning is very hot. So when it happens, it rapidly warms the air around it (about 30
000 degrees Celsius). Then, right after, the air quickly cools and contracts. This rapid warming
and cooling of air creates sounds, the sound of __________________.
_______________________- tornadoes can sometimes be produced from thunderstorms in
certain areas of the world. Again, during a thunderstorm, cooling sinking air from heavy rain
mixes with rising warm air. Their mixing can create powerful winds that blow in different
directions. Sometimes, these winds react with each other such that they all violently rotate into
a column that touches the ground. We call this rotating upward column of air a tornado.
Tornadoes can cause great destruction such as ripping apart buildings and uprooting trees.
___________________ - There are also low-pressure areas over water and it can also rain
heavily in these areas. Just like thunderstorms on land, great winds can be created over the
water. And sometimes, these winds are so great that a large swirling motion of wind happens
too. Often, this wind also receives more power from heat energy from the ocean and turns into
the most powerful storms: a hurricane in the Atlantic, a typhoon in the Pacific or a cyclone in the
Indian Ocean. These three storms are extremely destructive. Hurricane weather can kill people,
demolish buildings and destroy crops as they move and eventually hit land.
___________________ - another type of storm is the blizzard. Blizzards are very similar to
thunderstorms except that somehow warmer air is pushed upwards in a cold area. (Ex. between
2 fronts). This time, instead of heavy rain, there is heavy snow and again very strong winds.
Because of the heavy snow, visibility is reduced making it hard to see during a blizzard.
17. ____________________________ - Because severe weather can be dangerous, people are
constantly monitoring them to ensure safety. Whenever meteorologists detect conditions that
could (but not for sure) cause possible severe weather, they issue a ____________________.
Later, if the severe weather does actually happen, they issue a ___________________. People
should prepare accordingly whenever a watch or especially a warning is in effect (Ex. stay in the
basement, leave the area etc.)
18. Name: ______________________________________ Date: ________________________
Student Exploration: Weather Maps
Vocabulary: air mass, air pressure, cold front, high-pressure system, knot, low-pressure system,
precipitation, warm front
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
1. How would you describe your weather today? ____________________________________
_________________________________________________________________________
2. What information is important to include when you are describing the weather? __________
_________________________________________________________________________
Gizmo Warm-up
Data on weather conditions is gathered from weather stations all over
the world. This information is combined with satellite and radar images
to create weather maps that show current conditions. With the Weather
Maps Gizmo™, you will use this information to interpret a variety of
common weather patterns.
A weather station symbol, shown at right, summarizes the weather
conditions at a location.
1. The amount of cloud cover is shown by filling in the circle. A black circle indicates completely
overcast conditions, while a white circle indicates a clear sky.
What percentage of cloud cover is indicated on the symbol above? ____________________
2. Look at the “tail” that is sticking out from the circle. The tail points to where the wind is coming from. If
the tail points north, a north wind is moving from north to south.
What direction is the wind coming from on the symbol above? ________________________
3. The “feathers” that stick out from the tail indicate the wind speed in knots. (1 knot = 1.151 miles per
hour.) A short feather represents 5 knots (5.75 mph), a long feather represents
10 knots (11.51 mph), and a triangular feather stands for 50 knots (57.54 mph). Add the feathers to
find the wind speed.
What is the wind speed shown on the symbol above? ______________________________
19. Get the Gizmo ready:
Activity A:
Click New until you see a high-pressure system,
High-pressure represented by the symbol H.
systems Turn on Show Mobile Station B data.
Turn on Show land.
Question: What weather patterns are associated with high-pressure systems?
1. Observe: Air pressure is equal to the weight of a column of air on a particular location. Air pressure
is measured in millibars (mb). Use your mouse to move the mobile station B around the map.
Note how the air pressure changes as you move Station B towards the center of the high-pressure
system.
i. What do you notice? __________________________________________________
___________________________________________________________________
ii. Why do you think this is called a high-pressure system? ______________________
___________________________________________________________________
2. Observe: Select Show satellite image to observe any clouds near the system. What do you notice
about the cloud cover near the high-pressure system?
_________________________________________________________________________
High-pressure systems are regions where air moves downward. Usually few or no clouds form in
these conditions.
3. Measure: Measure the wind speed and direction around
the high-pressure system. Sketch the following on the
map at right:
The location of the high-pressure system.
Arrows to show the wind directions around the
high-pressure system.
The approximate wind speed at each arrow (in
miles per hour).
4. Analyze: Use your map to answer the following questions:
A. Is the wind pattern clockwise or counterclockwise? __________________________
B. Where are the strongest winds found? ____________________________________
___________________________________________________________________
20. Get the Gizmo ready:
Activity B:
Click New until you see a low-pressure system,
Low-pressure represented by the symbol L.
systems Check that Show Mobile Station B data and
Show land are on.
Question: What weather patterns are associated with low-pressure systems?
1. Observe: Use your mouse to move the mobile station B around the map.Note how the air
pressure changes as you move Station B towards the center of the low-pressure system.
A. What do you notice? __________________________________________________
___________________________________________________________________
B. Why do you think this is called a low-pressure system? _______________________
___________________________________________________________________
2. Observe: Select Show satellite image. What do you notice about the cloud cover near the low-
pressure system? _______________________________________________________
Low-pressure systems are regions where air moves upward. This can lead to condensation and
cloud formation.
3. Measure: Measure the wind speed and direction around
the low-pressure system. Sketch the following on the
map at right:
The location of the low-pressure system.
Arrows to show the wind directions around the
low-pressure system.
The approximate wind speed at each arrow (in
miles per hour).
Any clouds associated with the low-pressure
system.
4. Analyze: Use your map to answer the following questions:
C. Is the wind pattern clockwise or counterclockwise? __________________________
D. Where are the strongest winds found? ____________________________________
___________________________________________________________________
21. ______________________________________________
(Summary Note for Chapter 16, Section 3)
In the last class, you learned about certain specific type of local weather patterns (behaviors)
and also the general causes for them (ex. pressure change, fronts). In this lesson, you will learn
the basic ways that _____________________________ (weather men and women who study
the weather) _________________________________________ the weather patterns for
everyone to see.
First of all, meteorologists normally study weather patterns and communicate them by
illustrations –___________________- they actually occur. In other words, weather people try to
give everyone illustrated ________________________ of future weather to come so that people
can plan their lives accordingly and prepare for dangerous weather. Doing so requires careful
_________________________________ of various conditions of the atmosphere in numerous
different spots for a given region. Such monitoring and measuring occurs through the use of a
variety of ______________________ that measure things like
_________________________________________ ___________________. For instance,
Doppler radar carried by balloons can be used to gather such data. As well, other satellite
instruments attached to balloons located both in the upper atmosphere and on Earth’s surface
are utilized. Then, the weather people normally read their collected data and make
________________________ to show their forecasts. It is important to note, such forecast
maps can never be completely accurate because atmospheric conditions are constantly
changing.
General Make Up of Weather Maps- in order to keep consistency (sameness), most
meteorologists create their maps in the same and using the same symbols. Some of more
common methods and symbols for map making are given below briefly.
__________________________- Information on different types of data is all written together
spots on a map using a combination of symbols. Such a gathering of data and symbols at a
given spot is called a station model. For instance, in any station model, you can read the
temperature, the amount of clouds or cloud coverage (by a circle fill) and type of clouds, the
wind speed and direction (by a tail with ticks connected to the cloud amount circle) and other
pressure related data. See figure 18 in your textbook.
__________________________________ – In addition to entering station models on their
maps, meteorologists also include special lines that can run throughout their maps and even
occur as a series of circles radiating out from some location. These lines connect points of equal
pressure (isobars) or equal temperature (isotherms). Also, in the case of concentric circular
isobars, weather people write _______________________ at the centre of the radiating circles
to describe the amount of pressure. Further, you can look at the –space- between isobars to
know how fast the pressure is changing. If the lines are ___________________ from each other,
there is generally a ______________________________ in that area. But if the lines are
____________ to each other, there is generally a much ________________________________
in that area. In turn, you can use this pressure difference information to predict the
__________________________. Winds are usually strong in areas with big pressure changes
and gentle in areas with small pressure changes. Also, you normally see bigger pressure
differences and stronger winds ___________________________.
22. __________________________ – fronts are also usually illustrated in weather maps as you
learned in the last lesson. Cold fronts are shown by green lines and little triangles. Warm fronts
are shown by red lines and little half circles. Occluded fronts are represented by purple lines
with triangles and half circles. Stationary fronts are shown by red green lines with triangles and
half circles too. See figure 19 in your textbook for a visual.
