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Student Reference Notes: Weather and Space Systems
Our Solar System - the collection of eight planets and their moons in orbit around the
sun. Earth is part of this system and is the third planet from the sun.
*Our SUN is at the center of our solar system. Our sun is a STAR, which appears
larger and brighter than other stars because it is closer to Earth.
Order of the Planets (from the Sun)
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
My
Very
Educated
Mother
Just
Served
Us
Nachos
The Cycle of Day and Night – Earth’s rotation every 24 hours causes day and night.
Rotation – This is when a moon or a planet spins on its axis.
It is DAY for the part of the
Earth facing towards the sun
during rotation. It is NIGHT
for the part of the Earth
facing away from the sun
during rotation.
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*Earth’s rotation causes it to appear like the sun (and the moon and stars) are moving
across the sky. The sun rises in the east and sets in the west.
You can study how the sun
appears to move across the sky
by observing shadows. The
shadow of a post outside will
move from morning, to noon,
to late afternoon. Morning and
late afternoon shadows are also
longer because the sun is low in the sky. Noontime shadows are shorter because the
sun is high overhead.
The Reason for our Seasons – The tilt in the Earth’s axis causes different parts of the
Earth to have different amounts of sunlight as we revolve around the sun.
Revolution – the complete trip around an object that a moon or planet orbits
 The Earth takes 365 ¼ days to make a complete trip around the sun.
Summer for us is when the Northern Hemisphere is tilted towards the sun
and getting direct sunlight.
Winter for us is when the Northern Hemisphere is tilted away from the sun
and getting indirect sunlight.
*The Southern Hemisphere will always have the opposite season from the Northern
Hemisphere.
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The Seasons
Our Moon – Our moon rotates on its axis and revolves (orbits) around the Earth one
time every 29 ½ days. This is why the moon appears to change shape over the course
of about one month. This pattern of 8 phases is called the lunar cycle.
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Weather vs. Climate
1. Climate is the AVERAGE conditions of the atmosphere over a long period of time.
2. Weather is the DAILY conditions of the atmosphere.
 Sunlight is the energy that makes weather
 The sun heats different surfaces differently – some sunlight is absorbed;
some is reflected
Earth’s Climate Regions
The world can be divided into 3 main climatic zones depending on how hot, cold and
wet it is in an average year.
Tropical Zone – Closest to the equator – between the Tropic of Cancer and the
Tropic of Capricorn, two lines of longitude – this is the warmest region with some
extremely high temperatures
Temperate Zone – Found between the Tropical and Polar regions – this is
where we (and most people) live – this region has the most varied weather throughout
the year with many extreme highs and lows
Polar Zones - Furthest from the equator – this is the coldest region with some
extremely low temperatures – many parts are a tundra (cold desert) because it gets so
little rain fall each year
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Water Cycle
Condensation
Precipitation
Evaporation from
Sun’s Rays
Accumulation
Accumulation – the water collects in rivers, streams and oceans
Evaporation – when the liquid turns to gas (water vapor) , and rises in the air
Condensation – when the warm water vapor cools and hangs together creating
clouds, dew and fog
Precipitation – starts as ice high in the atmosphere, then as it gets nearer to the
ground it changes state.
Rain = the ice melted
Snow = the ice stayed frozen
Sleet = the ice melted then froze again
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Hail = the ice froze and melted repeatedly moving up and down in
the atmosphere until it took on a rounded shape
Clouds
Cirrus – thin wispy, feathery clouds usually found on sunny days
Cumulus – white puffy clouds – no rain, fair weather clouds
Cumulonimbus – big, dark rain clouds; thunderclouds
Stratus – low gray clouds that cover a large area; they bring light rain
Nimbus – means “rain cloud”
*Fog* – a stratus cloud that develops close to the ground
Waves
As the wind blows over the ocean’s surface it pushes against the water. This
transfers the energy from the wind to the water. The energy moves through the water
in waves.
Tides
The Earth and Moon’s gravity cause tides. Parts of the Earth in line with the
moon have high tides while the others have low tides. Tides change every 6 hours as
we rotate on our axis.
Low
Tide
Earth
High
Tide
North
Pole
moon
High
Tide
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Low
Tide
Currents
Ocean currents are like rivers in the ocean. Wind currents are fast-moving air. Some
currents are warm and some cold. Warm currents keep the land nearby warm; cold
currents keep the land nearby cool.
California
Current
Jet Stream
Gulf Stream
California Current – runs north to south along the west coast; the water
changes from cold to warm along the route
Gulf Stream – runs from south to north along the east coast; the water changes
from warm to cold along the route
Jet Stream – a fast flowing current of air that blows from west to east; it
separates cooler air to the north from warmer air to the south
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States of Matter
State
Solid
Liquid
Gas
Description
Has a definite shape and volume
Has a definite volume but takes the shape of container
Takes the shape and volume of its container
*Water can change its state by adding or taking away heat. In the water cycle,
evaporation turns liquid water into gas. Condensation turns the gas back into liquid
water droplets or solid ice crystals. When precipitation occurs, rain is a liquid. Snow,
sleet, and hail are solid.
Conditions of the Atmosphere –
Weather is the conditions of the atmosphere in a certain place at a certain time. The
following air conditions affect the weather we are experiencing: Wind, Heat Energy,
Air Pressure, & Moisture (W.H.A.M). Each of these conditions also has special
instruments (tools) that are used to measure them.
Wind – Wind is moving air. Warm air is light and rises. Cooler air moves in to
replace it. This movement of air is wind. An Air Mass is a large area of air that has
the same temperature and humidity.
Front = where air masses meet and push one another aside.
Cold Front – when the colder air replaces the warmer air. A cold front is
represented as a line with the teeth pointing toward the direction of
movement.
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Warm Front – when the warmer air replaces the cooler air. A warm front
is represented as a line with half circles pointing toward the direction of movement.
Anemometer – measures wind speed – The wind pushes small
cups and makes it spin. The faster the wind is blowing the faster
the cups spin.
Wind Vane – shows the direction the wind is coming from
– Letters on the wind vane show which way is north, south, east
and west. The arrow turns to point into the wind. If it is pointing
north then that means the wind is blowing north.
Heat Energy
Air temperature changes almost all of the time. It is usually warmer during the
day than it is at night.
Radiometer – measures the amount of sunlight – It
is an airtight globe with a small vane inside. When the
radiometer is placed in the sunlight the spindles inside begin to
spin. The stronger the sunlight the faster they spin.
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Thermometer - measures temperature – The numbers on a thermometer
are the scale that shows the temperature in degrees. Some thermometers
use the Fahrenheit scale while others use the Celsius scale. Many
thermometers show both.
Air Pressure
Air has mass. Because it has mass, it has weight. Air pressure is the weight of
air pressing on everything around it, in all directions. When the air pressure changes,
you can tell that the weather will change.
H
L
High Pressure – rising air pressure means that clearer weather is coming.
High pressure = good weather
Low Pressure – falling air pressure means that wet weather is coming.
Low pressure = bad weather
Barometer – measures air pressure – Three conditions
affect air pressure: water vapor, temperature, and altitude.
Moisture
Air has different amounts of water vapor in it. Sometimes it has only a little
amount and the air feels dry; sometimes it has a lot and the air feels damp and sticky.
The amount of water vapor changes with the temperature. Humidity is a measure of
how much water vapor is in the air.
Hygrometer – measures the humidity – This measures the
relative humidity. This is the amount of water vapor that the air is
holding compared with the amount that it could hold at that
temperature.
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Rain Gauge – measures rainfall – As more water
vapor condenses, the droplets grow larger. When the drops
get too large and heavy, they fall as one of the forms of
precipitation.
Weather Maps:
*Meteorologists show weather data they’ve collected using symbols on a weather map
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