Transcript Mrs. Passell*s Weather Test Review

Mrs. Passell’s Weather Test Review
revised 2.9.14
The test will assess your understanding of
clouds, precipitation, water cycle, fronts, high
& low pressure areas, weather maps, weather
instruments, heat transfer & storms .
It will not cover the layers of the atmosphere
or air as a mixture.
WHO’S STUDYING THE WEATHER?
Besides Mrs. Passell’s
students?
METEOROLOGISTS!
TV weatherpersons
usually don’t have a
degree in meteorology,
the study of weather.
CLASSIFYING TYPES OF CLOUDS
Clouds are classified by their
shapes and their altitude. You
will need to be able to identify
stratus, cirrus, and cumulus
clouds and describe the kind of
weather each one brings.
COMMON TYPES OF CLOUDS
.
STRATUS CLOUDS
 Stratus clouds are not
individual “units’.
 These are the lowest
clouds.
 They produce widespread
rain or snow that may last
days longer than a
thunderstorm.
 Fog is a stratus cloud
close to the ground.
CUMULUS CLOUDS
 Puffy clouds like the ones you
drew in first grade
 Fair weather clouds
CUMULONIMBUS CLOUDS
• Bring heavy rains,
lightning, thunder
• May bring violent
weather
• Also called
Thunderheads
http://www.crh.noaa.gov/images/ilx/swop/clouds.jpg
CIRRUS CLOUDS
• High altitude, thin
clouds
• Wispy, like feathers
• Made of ice crystals
• Sometimes called
“mare’s tails”
http://www.met.tamu.edu/class/Metr304/Severedir/CirrusCl
ouds.jpg
FRONTS
An AIR MASS is the large body of air that has the
characteristics of the land over which it develops. The whole
air mass will have the same temperature, pressure and
humidity.
A FRONT is the place
where two air masses
meet.
SYMBOLS FOR FRONTS
think of cold pointy icicles
think of the warm sun rising in the east
- not on the test
think of a stationary
exercise bike - - you’re
pedaling but not going anywhere!
MOVEMENT OF FRONTS
The front is moving in the direction of the
points or half-circles.
Stationary fronts are stationary so they
are not moving!
MOVEMENT OF FRONTS
Remember that COLD AIR IS MORE DENSE than WARM
AIR.
Because WARM AIR is less dense, it doesn’t push under
the cold air. It rises up over it.
When the COLD AIR approaches warm air, it pushes under
the warm air.
Think of a cotton ball (less dense warm air) approaching a
stone (more dense cold air). Can’t push under, got to go
over!
WARM FRONT
Remember that warm air is less dense than cold air so it will
slide up over the more dense cold air.
WARM FRONT
The weather is rainy or
snowy as the front
approaches and the
temperature starts to rise.
Warm Front. Image Credit: NOAA;
http://tinyurl.com/c3o9gtu
COLD FRONT
A cold front pushes under the less dense warm air.
Violent storms can occur.
STATIONARY FRONT
The WARM FRONT and COLD FRONT come together along
a stationary front. The weather will be unsettled and for a
few days.
WATER CYCLE/ HOW CLOUDS FORM
.
WATER CYCLE/ HOW CLOUDS FORM
During CONDENSATION the moisture that has evaporated
and becomes water vapor cools as it rises in the atmosphere.
The water vapor condenses to form clouds. Water drops that
form in the clouds fall back to earth as precipitation.
WATER CYCLE FOR KIDS
Think about a cold window. If you breathe
on the window, your warm breath will form
water droplets on the cold surface.
PRECIPITATION : RAIN & SNOW
Rain – liquid water; most
common form of
precipitation
Snow - - Just like rain
except it passes through
layers of freezing air as it
returns to Earth
PRECIPITATION : SLEET, HAIL &
FREEZING RAIN
Sleet - - rain passes
through cold air close to
the ground
Hail - - ice crystals rise &
fall within the thundercloud; when they become
too large, they fall to Earth
Freezing Rain – regular
land that freezes when it
lands on surfaces that are
32º or lower
ISOBARS
These lines
connect places that
have equal air
pressure.
The closer together
the lines are, the
stronger the winds
will be.
HIGH PRESSURE AREAS
High pressure is
indicated with an
“H” The weather
will be fair with clear
skies & maybe
some puffy cumulus
clouds..
HIGH PRESSURE =
rising barometric pressure
.
LOW PRESSURE AREAS
Low pressure systems are marked with an “L”. Cloudy
weather & precipitation is found in low pressure areas. The
center of all storms, including hurricanes, are low pressure
areas.
.
LOW PRESSURE =
falling barometric pressure
WINDS
Energy from the sun causes uneven heating of
Earth’s surfaces. This causes winds.
http://astronomy.nmsu.edu/tharriso/ast110/convection3.gif
WINDS
Air moves from areas of high pressure to areas
of low pressure.
HURRICANE OR TORNADO?
Tornadoes are very different from hurricanes even though
they are windstorms that cause much destruction .
A hurricane is a large low pressure system that covers a wide
area.
A tornado is a a more localized storm that lasts a shorter
amount of time.
http://graphics8.nytimes.com/images/2013/05/24/us/Tornado1/Tornado1-superJumbo.jpg
http://www.phe.gov/Preparedness/planning/playbooks/hurricane/Page
s/default.aspx
HURRICANES
These storms form along the warm tropical waters near the equator
http://spaceplace.nasa.gov/hurricanes/
HURRICANES
If you could slice into a tropical cyclone, it would look something
like this. The small red arrows show warm, moist air rising from the
ocean's surface, and forming clouds in bands around the eye. The
blue arrows show how cool, dry air sinks in the eye and between
the bands of clouds. The large red arrows show the rotation of the
rising bands of clouds.(http://spaceplace.nasa.gov/hurricanes/)
TORNADO
A tornado forms from a thunderstorm. Warm moist air meets
cool dry air. Changes in wind speed and direction at different
altitudes cause the spinning to begin.
DROUGHT
Drought occurs when there is little or no
precipitation for a long time.
HOW LARGE BODIES OF WATER
AFFECT WEATHER
Large bodies of water hold their heat longer than
areas of land far from water.
56 °
68 °
WEATHER INSTRUMENT:
ANEMOMETER
*measures the speed of the
wind;
strong winds cause the cups
to spin faster
WEATHER INSTRUMENT:
BAROMETER
measure air pressure in inches or mercury or millibars
WEATHER INSTRUMENT:
HYGROMETER or PSYCHROMETER
measures the humidity (the amount of moisture in the air)
WEATHER INSTRUMENT: WEATHER
VANE or WIND VANE
Nevit Dilmen
shows the direction the wind is blowing
WEATHER INSTRUMENT:
THERMOMETER
measure the temperature
WEATHER INSTRUMENT: RAIN
GAUGE
measure the amount of rainfall
How Does Air Pressure Change
With Altitude?
As you climb higher up the
mountain the air pressure is
less than down at sea level and
it becomes more difficult to
breathe.
HEAT TRANSFER: CONVECTION
• When air or water is heated, the
molecules move faster and
farther apart, reducing their
density and causing them to rise.
• Cooler air or water molecules
move more slowly and are
denser than warm air or water.
The cold air sinks down. When it
warms up again, it will rise
again.
• Remember the rising air helps
sailplanes & eagles to soar.
HEAT ENERGY TRANSFER:
CONDUCTION
 Conduction is heat
transfer by direct physical
contact. The object has to
be touching the heat
source!
 Conduction can happen
in solids, liquids and
gases.
 Example: An ice cube will
melt in your hand
because the heat from
your hand is absorbed by
the ice.
http://commons.wikimedia.org/wiki/File:Cup_for_Heat_Conduction_2010-08-17.png
HEAT TRANSFER : RADIATION
• Radiation is energy transfer through empty space.
• It travels in the form of light waves.
• Sunlight is a form of radiation.
CONDUCTION, CONVECTION,
RADIATION
.
http://greenstarpanels.com/portfolio/heat-gain-loss-in-buildings/
?
.
?
Adapted from >
Mr. B. Fontaine
Mrs. J. Phipps
Mrs. C. Koop
Parts of this powerpoint were kindly donated to
www.worldofteaching.com
SOURCES
Tornado> http://www.weatherwizkids.com/weathertornado.htm
Drought > http://en.wikipedia.org/wiki/File:Current-USDM.gif
high to low pressure >
http://hsc.csu.edu.au/primary_ind/prim_ind_240/compulsory/AHCW
RK201A/3264/pressure_cells.htm