Meteorology

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Meteorology Climate
A unit about weather, storms, short term weather
and long term climate
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Meteorologythe study of
weather
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What is
the current atmospheric conditions of a specific
place at a specific time
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How is weather different from climate?
What is the major cause of weather???
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The study of our atmosphere
SEE ESRT page 14 .
Broken into 4 layers due to
The four layers from the bottom to top are
Ozone is a gas that prevents ultraviolet
radiation from reaching the Earths surface.
Ozone is found between 12 and 50 km up in the
atmosphere in which layer?
What are the pauses (tropopause, stratopause,
mesopause) ?
Boundaries between atmosphere layers.
Temperature s and changes opposite
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Thermosphere gently fades away into space
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Use the ESRT to answer the following questions.
Q Which layer of the atmosphere contains the
most water vapor?
Q Which layer of the atmosphere has the
greatest amount of air pressure?
Q In which layer does weather occur?
Q What is the composition of layer we live in?

(See ESRT pg.11)
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• Patterns of weather variables can be shown as

Satellite
Radar
Cross - Sections
Computer Models
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Station Modelsa symbol used on weather map to
show a huge amount of data in one very small spot
on a map
Data shown includes but is not limited to
temperature, air pressure, dew point, wind speed
and direction, cloud cover, precipitation,
current weather conditions, etc.
017
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-27
¼
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1.2
See ESRT page 13 .
Refer to handout on station models for more
information!!
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Air Pressure Rule On the station model if the
number is 500 or more, add a 9 in front of the
number and a decimal before the last number.
if the number is less than 500, add a 10 in
front of the number and a decimal before the
last number
Albany
Chicago
Rochester
Atlanta
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(No Transcript)
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Weather Variables (there are 6 of these!)
1. Temperature
Instruments used
a. Thermometer
b. Thermograph
ConversionsSee ESRT page ____
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On a weather map, ___________ are drawn to
connect equal temperatures.
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2.) Air pressurethe weight of the atmosphere on
the Earths surface
Instruments used

• Barometer
• Barograph

ConversionsSee ESRT page ____
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On a weather map, ___________ are drawn to
connect equal air pressure.
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What makes air heavy or light?
Dry air is much heavier than moist air.
As water vapor (gas) is added to a unit of air,
you are adding a lighter gas and heavier nitrogen
and oxygen are pushed out
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ANTICYCLONE
CYCLONE

• High pressure air masses have winds that blow
  in the Northern Hemisphere.
  
• Low pressure air masses rotate in
  the Northern Hemisphere.

and
and
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3.) Windhorizontal movement of air due to
changes in air pressure
Instruments used

• Anemometer

-
-

• Wind Vane

Winds are named for the direction from which it
comes
Ex. North wind blows from the north to the south
Name these winds
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There are 2 types of wind
Global Wind (Planetary Winds)
Naturally occurring winds in the atmosphere due
to major pressure changes, latitude, angle of
insolation
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See ESRT page
Winds curve due to the Winds blow from low pr
essure, High Pressure
Coriolis Effect
____ pressure to ___pressure
____
____
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Hurricanes form off the coast of Africa and
travel westward across the Atlantic Ocean towards
the United States. WHY?
This is the direction the global winds push them
across the ocean
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Why do hurricanes change their paths when they
reach 30? N?
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Local Winds
a.) Convectionair warms rises then cools
sinks
Causes changes in surface _________
Cold sinks
Cold sinks
Warm rises
Warm rises
?_
?_
Global winds push the whole system W to E
Chicago
Rochester
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b.) Land and Sea Breezes
Land heats up _____ than water
Warm air ____ over the warm land, expands then
____ ___ over the water
Land cools off ____ than water
Warm air rises over the ______ water, expands,
then cools sinks over the _____
http//www.classzone.com/books/earth_science/terc/
content/visualizations/es1903/es1903page01.cfm?cha
pter_novisualization

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c. Monsoons
In ________, air over continents has ____ air
pressure and air over seas has ____ air pressure.
The pattern reverses in winter. The reversing
winds are called _________.
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4.)Moisture
Use ESRT page 1 to find out the amount of energy
required to change from one phase to another
How much energy is required to change liquid
water into water vapor?
How much energy is required to change hail to a
raindrop?
_______
__________
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Relative Humiditya comparison of the amount of
water vapor the air IS holding to the amount of
water vapor the air CAN hold
Warm air can hold more water vapor than cold air
2 Instruments used
Hygrometer
Psychrometer
Evaporation is a cooling process!!!
Amount of cooling depends on the rate of
evaporation
Therefore, the greater the difference between the
dry bulb and the wet bulb, the drier the air
(more evaporation took place)
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How to use the ESRT to determine relative
humidity (See page ____)
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• Locate the dry bulb reading on the left hand side
  of the chart
  
• Subtract the wet bulb reading from the dry bulb
  reading.
  
• Locate the difference along the top of the chart
• Follow the horizontal row for dry bulb across and
  follow the difference column down until the two
  meet. This is your RH.

Practice Problems
1.) Dry bulb 28C Wet bulb 20 C
Difference
RH
8C
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This is the relative humidity!
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How to use the ESRT to determine relative
humidity (See page ____)
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• Locate the dry bulb reading on the left hand side
  of the chart
  
• Subtract the wet bulb reading from the dry bulb
  reading.
  
• Locate the difference along the top of the chart
• Follow the horizontal row for dry bulb across and
  follow the difference column down until the two
  meet. This is your RH.

Practice Problems
1.) Dry bulb 28C Wet bulb 20 C
Difference
RH
2.) Dry bulb 4C Wet bulb -2 C
Difference
RH
3.) Dry bulb -14C Wet bulb -14C
Difference
RH
8C
6C
0C
____
____
_____
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Dew point
the temperature air cools to in order to be
saturated (full of water vapor)
less
Cold air holds water vapor than warm air
Instruments used
Hygrometer or Psychrometer
How to use the ESRT to determine dew point (pg
12)
Same as relative humidityjust make sure you use
the DEW POINT chart!!
Practice Problems
1.) Dry bulb 28C Wet bulb 20 C
Difference
DP
8C
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Dew point
the temperature air cools to in order to be
saturated (full of water vapor)
less
Cold air holds water vapor than warm air
Instruments used
Hygrometer or Psychrometer
How to use the ESRT to determine dew point (pg
____)
12
Same as relative humidityjust make sure you use
the DEW POINT chart!!
Practice Problems
1.) Dry bulb 28C Wet bulb 20 C
Difference
DP
2.) Dry bulb 4C Wet bulb -2 C
Difference
DP
3.) Dry bulb -14C Wet bulb -14C
Difference
DP
8C
6C
0C
____
____
____
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5.)Clouds
Process of formation

• Air rises expands
• Air cools to the dew point
• Water vapor condenses on condensation nuclei
  (dust, pollen, ash particles)

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6.) Precipitation
The forms of precipitation include drizzle, rain,
sleet, snow, freezing rain, and hail.
Instruments used
Precipitation Gauge
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Mountains regions are affected by windward and
leeward winds
http//www.pbs.org/wgbh/nova/kilimanjaro/weather.h
tml

Windward
Leeward
Air rises, cools expands Precipitation forms
Air sinks, warms compresses Dry, arid regions f
orm
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Atmospheric Relationships
All of these variables affect each other. Can
you determine how one affects the other? Can you
draw graphs of these relationships?
a.) Air temperature and the capacity to hold
water
As temperature increases, capacity increases
Capacity
Temperature
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b.) Temperature and density
As temperature increases, density decreases
Density
Temperature
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c.) Temperature and air pressure
As temperature increases, air pressure decreases
Air Pressure
Temperature
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d.) Relative humidity and air pressure
As relative humidity increases, pressure decreases
WHY???
Water vapor is a light weight gas.
Air pressure
Relative humidity
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e.) Temperature, dew point and the chance of rain
The closer the temperature is to the dew point,
the greater the chance of rain as the air is more
humid.
Chance of rain
Difference between temperature and dew point
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The closer the temperature and the dew point, the
more humid the air.
Which city below has the most humid air?
Albany
Chicago
Rochester
Atlanta
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f.) Air pressure and the chance of rain
There is a greater chance of rain when the
pressure is low
high
Chance of Rain
low
low
Air Pressure
high
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g.) Precipitation and atmospheric transparency
As precipitation increases, atmospheric
transparency increases
high
Atmospheric Transparency
low
low
Precipitation
high
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h.) Altitude and pressure
As altitude increases, air pressure decreases
high
Air pressure
low
low
Altitude
high
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Air Massa large body of air that has similar
__________________ properties throughout.

• cP Continental Polar (Central Canada)
• cT Continental Tropical (Mexico)
• mT Maritime Tropical (Warm Ocean)
• mP Maritime Polar (Cool Ocean)
• cA Continental Arctic (Tundra)

Source Regions
Source regions give the air masses their
characteristics.
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Air Masses that affect the U.S.
___
___
___
___
___
____
___
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Fronta transition zone between two air masses
Map symbols are in your ESRT page 13.
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• Cold Front
• Brings cold air
• Cold air moves than warm.
• Precipitation can be heavy

faster
right on the front.
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Profile View
Warm is pushed up along the front, air rises,
cools to dew point and forms clouds
precipitation. ( maybe a thunderstorm)
Warm
Cold
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Cold front symbol
Map View
Cold air mass
Warm air mass
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• Warm Front
• Brings warm air
• Light rain or light winter precipitation is
  possible

before and as the front passes.
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Profile View
Air rises along the front, cools to dew point and
forms clouds
Warm
Cold
Steady rain that occurs all day long! This is a
slow moving front
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Warm front symbol
Map View
Warm air mass
Cold air mass
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Occluded front consists of a
and a faster moving The cold front
catches the warm front.
warm front
cold front.
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Occluded front symbol
Map View
Why is the front purple?
Red (warm) Blue (cold) Purple (occluded)
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Rain
Freezing rain can form if the cold air is below
32ºF.
Freezing rain
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almost non-moving
Stationary fronts are
often bring several days of cloudy, wet weather
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Stationary front symbol
Map View
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• Fronts are the leading edge of the air masses
  center around a LOW. For example, a warm front
  is at the beginning of the warm air with higher
  temperatures behind it. Station models will show
  the direction of air movement. Label the warm
  cold air masses. Draw the symbols on the fronts.

WARM
COLD
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current of fast moving air

• The jet stream is a
  found in the upper levels of the
  atmosphere, usually between 10-15 km (6-9 miles)
  above the earth's surface. What layer would this
  be?
• Weather systems generally follow planetary wind
  belts. In the U.S. they move from to
  .

___
___
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Thunderstorms

• What are the 3 ingredients to make one?
• Water vapor
• Instability (air must cool rapidly with height)
• Uplift (air rises)
• Ex. convection or cold front

What causes thunder? LIGHTNING! Thunder is the r
apid expansion of air due to lightning.
What is a severe thunderstorm?
One that can produce frequent lightning, heavy
downpours (flash floods), strong winds, hail, and
even tornadoes.
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Lightning Safety

• Go inside. If shelter is not available get into
  a car or find a low spot away from trees and ball
  up with head between knees. Have as little
  contact with ground as possible.
• Avoid using electrical appliances such as the tv,
  computer, or corded telephones. (cordless or cell
  phones are ok to use)
  
• Stay away from open water
• Do not take a shower or a bath

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• Hail forms when strong currents of rising air,
  known as updrafts, carry rain droplets above the
  
  
• in
  thunderstorm clouds and the water
  
• Lightning kills
• people in the United States than tornadoes,
  floods, and hurricanes.

freezing level
freezes into ice.
more
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TORNADO or TWISTER a violently rotating column
of air that usually touches the ground.

• Has a funnel-shaped cloud of moisture, debris or
  dust
  
• Tornadoes occur most often in
• in the
• air from Canada collides
  with
  
• air from the Gulf of Mexico

Tornado Alley (Texas to N. Dakota)
spring early summer
Cold dry
warm moist
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Tornado Safety

• A tornado watch means that conditions are
  favorable for producing a particular weather
  event, but that it has not formed yet.
  
• A tornado warning means that a tornado is
  actually present and moving in the warn vicinity.
  Residents should take immediate shelter!!!
  
• Tornado Warning Signs
• Sounds like a freight train
• Air is calm just before it hits
• Occurs on the trailing edge of a thunderstorm
• Wizard of Oz-type funnel appears

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Tornado Safety

• During a tornado
• Go to a . If you do not have a
  basement, go to
  
• on the lowest
  floor such as a bathroom or closet
  
• get under a sturdy piece of furniture, like
• Get out of automobiles. Do not try to
  outrun a tornado in your car, leave it
  immediately
  
• If youre outside, go to a

basement
an interior room
without windows
a table
ditch or low lying area and lie flat in it.
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Blizzard a low pressure storm over land that
brings dangerously cold temperatures and high
winds.
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Winds must exceed mph.
20º F
Temperatures must be ______________ or lower.
Visibility is reduced due to falling and/or
blowing snow
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Blizzard Safety Precautions
Avoid unnecessary travel. Seek shelter immediate
ly! You are in danger of getting frost bite (or
worse)!

• Assemble a Disaster Supplies Kit for your
  automobile that includes
  
• First aid kit and essential medications
• flashlight and extra batteries
• Nonperishable food (energy bars, granola bars,
  etc.)
  
• Bottled water
• Extra warm clothing, including boots, socks,
  mittens, and a hat
  
• If stuck, run the engine for a few minutes at a
  time be sure tailpipe is clear of snow

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Buffalo, NY Blizzard of 1977
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Lake Effect Snow
Forms when cold, dry air blows over the warm lake
Wind direction plays a key role in where the snow
belts will be
Snow belt
Snow belt
snow
snow
WEST wind NNW wind NW wind
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HURRICANE FORMATION

• Warm air rises, above the ocean and cools to form
  clouds.
  
• Clouds begin to rotate inward and a low pressure
  system (a tropical depression) develops.
  
• As more warm air rises, the system continues to
  be fed more humid air and the storm begins to
  look like a pinwheel.

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Why do hurricanes change their paths when they
reach 30? N?
Their paths are turned by the global winds that
now blow from the SW.
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• Hurricanes use energy from the warm ocean water
  to grow stronger. As long as it has warm water a
  hurricane will continue to grow. This is why
  hurricanes don't last very long once they move
  over land.

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What happened to the strength of Katrina on Aug
26?
Strength decreased because the energy source was
cut off
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Storm Surgewall of water that is pushed ashore
due to high wind speeds of hurricane.
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Hurricane Safety Precautions

• Install hurricane shutters.
• Remove diseased and damaged limbs from trees.
• Evacuate when toldlet relatives/friends know
  where you will be
  
• If you are not advised to evacuate, stay indoors,
  away from windows.
  
• Be aware that the calm "eye" is deceptive the
  storm is not over. The worst part of the storm
  will happen once the eye passes over and the
  winds blow from the opposite direction.
• Be alert for tornadoes.
• Stay away from flood waters. If you come upon a
  flooded road, turn around. More people die in
  hurricanes from the storm surge and flooding

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Compare and contrast a tornado and a hurricane in
terms of duration, location of formation, damage,
and emergency preparedness.
Tornado
Hurricane
Short duration (few minutes to an hour or so)
Longer duration (several days)
Form over land due to collision of mT and cP air
masses
Form over warm ocean and are pushed westward due
to planetary winds
Destruction can be up to a mile wide and several
miles long
Destruction can be hundreds of miles wide with
the worst destruction on coastlines.
Destruction mostly due to high winds and objects
blown/thrown by the high winds
Destruction mostly due to flooding and high winds.
Evacuate, board up windows, go to interior room
away from windows
Go to basement, cover head
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In normal conditions, the trade winds blow
towards the west across the Pacific pile up
warm surface water
El Nino
http//weather.weatherbug.com/weatherbugachieve/lp
/connections.asp?month1showspecialno
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• Results
• Less upwelling of nutrient-rich cold water to
  cool the surface.
  
• Bottom of food chain weakened.
• Warmer surface water.
• Rain flooding in So. America drought in
  Indonesia.
  
• La Nina has the opposite effects.

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Climate
The climate of any region is largely determined
by its geographic position. Four aspects of the
geography of a region that influence climate are
Latitude
Distance from a large body of water
Direction of the prevailing winds
Elevation
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Latitudeas latitude increases, the climate
generally gets colder

• Distance from a large body of water
• closer will have cooler summers and warmer
  winters (marine climate) with a
  smaller range in annual temperatures
  
• farther will have hotter summers and colder
  winters (continental climate) with a larger range
  in annual temperatures

Direction of prevailing winds
-if winds blow off the ocean humid
-if winds blow off land dry
-also recall windward (cool wet) vs. leeward
(hot dry) sides of mtn.
Elevationas elevation increases, temperature
decreases