Weather and Water
Part 1: What is Weather?
Weather – conditions of the atmosphere at a given time with
respect to heat, moisture, pressure and motion
Weather tools (thermometer measures temperature in degrees
C, barometer measures air pressure in MB’s, hygrometer measures
humidity in %, anemometer measures wind speed in MPH, wind vane
measures wind direction in N,S,E and W, psychrometer measures
relative humidity)
Part 2: Where is the Air?
Mass – amount of matter in an object
Atmosphere – a thin layer of gases that surround the Earth
Weight – a pull or force between Earth and the matter of an
object
compressed - something being forced into a smaller space
Know Layers of the Atmosphere - (Troposphere is where all
weather takes place, Stratosphere contains the Ozone layer,
Mesosphere, Thermosphere the hottest layer, Exosphere is the
last layer separating our atmosphere and space)
Name the three most abundant gases in the atmosphere:
Nitrogen 78%, Oxygen 21%, Argon 1%
As you rise higher in the atmosphere what happens to air pressure
and temperature? They both go down
Part 3: Season and Sun
Know the different seasons (the positioning of the earth)
Define these terms:
Equinoxes (2) - Vernal/Spring Equinox March 21st
(Equal Day length)/ Autumnal/Fall Equinox September
21st (Equal Day length) The Earth’s tilt is not pointed
toward or away from the sun
Solstices (2) – Winter solstice December 21st (Shortest
day and Earth’s tilted away from the sun) Summer
Solstice June 21st (Longest Day and Earth is titled toward
the sun)
Revolve/ Revolution - counter clockwise and it takes 365
and ¼ days, also cause season (With Tilt)
Rotate/ Rotation – counter clockwise and it takes 24
hours, also causes day and night
Solar Angle – the angle at which light strikes the
Earth’s surface
Beam Spreading – the way a light beam covers a surface
when light hits the Earth’s
Seasons are caused by the Earth’s tilt, 23.5 degrees, and
Revolution
Know which receives more direct sunlight summer or winter
and why? Winter, because earth is tilted toward the sun
Understand the importance of the North Star = Earth’s tilt
always points to the North Star
Part 4: Heat Transfer
Radiant Energy – Energy that comes from the sun
Radiation – is the energy and can be visible or invisible
Differential Heating – when different materials heat up at
different rates
Conduction – Energy transfers of energy between molecules or
atoms when they come into contact with one another
Reradiation – all matter gives off energy and it travels from hot
to cold
Part 5: Convection
Density – Mass per unit volume = Mass / Volume
Convection – the movement of air based on density,
because less dense air rises and dense air falls.
Explain and Draw the Convection Cell:
Part 6: Water in the Air
Condensation - when water changes from a gas to a
liquid
Humidity – amount of water vapor in the air
Saturation – when air contains as much water vapor as it
can hold
Relative Humidity – amount of water vapor in the air
compared to the amount of water vapor needed to
saturate the air
Transpiration – when water leaves plants as vapor
Condensation Nuclei - particles on which water vapor
condenses
Evaporation – is when water turns into a gas
Dew Point – the temperature at which water condenses
Water vapor – water in the air in the form of a gas
Precipitation – any form of water that falls from a cloud
Draw and label how a cloud is formed:
Part 7: The Water Planet
Review how the water on this planet is distributed:
97% of Earth’s water is Ocean water
Most of the Fresh water is in Glaciers and Icecaps
How much of the Earth’s surface is covered by water? 70%
Draw and label the water cycle?
Part 8: Air Pressure and Wind
Anemometer – tool used to measure wind speed
Barometer – tool used to measure air pressure, millibars
is the unit used
Wind – caused by differences in air pressure
Isobars – lines on maps connecting places together with
the same air pressure
Global winds – Winds that happen on a larger scale,
move from H to L pressure, predictable winds
Local Winds – winds that happen on a smaller scale ,
move from H to L pressure
Coriolis Effect - the bending of winds east or west
because of Earth’s rotation
Prevailing Winds – predictable Global Winds
Explain how air pressure creates wind (Nature’s Balancing
Act)?
Air moves from High Pressure areas to low pressure
areas
Know and be able to explain the four local winds (Mountain
Breeze, Sea Breeze, Valley Breeze, and Land Breeze)
Be able to read a pressure map
Part 9: Weather and Climate
Stagnant Air – air that does not move
Source Regions – the place that an air mass gets its
name from
Air Masses – large thick bodies of air that are uniform in
Humidity and Temperature
Staff/ shaft – line that extends from cloud coverage,
names Wind direction
Barbs – are the small lines at the end of a shaft/ staff
gives wind speed
Weather – conditions of the atmosphere at a given time
Climate – the average weather conditions over a long
period of time; two main factors in determining climate is
temp and annual rain fall
Global Warming – when Earth’s temperature rises
because of an increase in carbon dioxide
Greenhouse Effect – process by which gases hold heat in
the atmosphere (Increased CO2)
Ozone Layer – a layer in the Stratosphere that absorbs
ultraviolet radiation
Stationary Front – When a warm air mass and a cold air
mass meet and do not move
Be able to identify and label different air masses (Continental
are dry and form over land, Maritime are humid and form over
water, Polar are cold and they move east and south, Tropical
warm and mover north and east)
Draw and label a warm front and a cold front
Be able to read and interpret a weather map
(Look at the sample weather map)
Know the Temperature Zones? Polar, Tropical and Temperate
zones