Weather

Topic 7

Weather

Topic 7

Created by P. Bordas MS, CCC-SLP

Remember to wait for the vocabulary word to pop up at the end! Can you guess it before it comes up?

Weather Variables

Include temperature, air pressure, wind, moisture conditions, cloud cover,

precipitation, and storms

teachers.saschina.org/aolivas/

Troposphere

The part of the atmosphere immediately above the Earth’s surface.

Where most of the weather changes occur

http://www.fas.org/irp/imint/docs/rst/Sect14/atmosphere.jpg

Atmospheric Pressure and

Density

Atmospheric Pressure (or barometric pressure or air pressure)

The pressure due to the weight of the overlying atmosphere pushing down on

any given area

http://www.mercarta.com/desktop/map/GulfOfMexico/BarometricPressure_Map.jpg

Barometers

Instrument used to measure air pressure

http://www.maximum-inc.com/images/products/products/PRA-LE.jpg

Isobars

Used to show air pressure on weather maps

http://www.newmediastudio.org/DataDiscovery/Hurr_ED_Center/Hurr_Structure_Energetics/Closed_Isobars/Closed_Isobars_fig02.jpg

Wind

Air Pressure Gradient

The difference in air pressure for a specific distance

http://www.physicalgeography.net/fundamentals/images/thermal2.GIF

Anemometer

Instrument used to measure wind speed

http://wings.avkids.com/Book/Wright/Images/anemom-Bertie.jpg

General Circulation of the

Air in the Troposphere

Jet Streams

Bands of easterly moving air at the top of the troposphere

http://wings.avkids.cohttp://nevis.k12.mn.us/academics/science/2jetstreams.gifm/Book/Wright/Images/anemom-Bertie.jpg

Planetary Wind Belts Results because of the Coriolis effect (winds moving

away from high air pressure and deflected to the right in the Northern Hemisphere and to the left in

the Southern Hemisphere). Within these, the winds move generally in a specific direction much of the

time so they are prevailing winds.

http://images.google.com/imgres?imgurl=http://www.grossmont.edu/judd.curran/images/A07_14.gif&imgrefurl=http://www.grossmont.edu/judd.curran/outline2.htm&usg=__4EzI0dKYxO5-4b5Agt0poS3Hl3c=&h=258&w=411&sz=26&hl=en&start=12&um=1&itbs=1&tbnid=MmWjuknAdEitVM:&tbnh=78&tbnw=125&prev=/images%3Fq%3Dplanetary%2Bwind%2Bbelts%26um%3D1%26hl%3Den%26safe%3Dactive%26rlz%3D1T4GZAZ_enUS316US317%26tbs%3Disch:1

Monsoons

Extreme weather changes caused by the shifting wind and pressure

belts

http://staff.harrisonburg.k12.va.us/~cwalton/My%20Pictures/monsoons.jpg

Atmospheric Moisture

Water Vapor

Gaseous water in the atmosphere

http://helloworldbea.files.wordpress.com/2008/05/watervapor.jpg

Humidity General term that refers to the

water vapor content of the atmosphere

http://www.electrical-res.com/EX/10-19-03/humidity.jpg

Relative Humidity The ratio of the amount of water

vapor in the air (absolute humidity) to the maximum amount it can hould (its moisture capacity)

http://www.tqnyc.org/2009/00767/relativehumidity.gif

Dew Point

The temperature at which air is filled with water vapor

http://virtualskies.arc.nasa.gov/weather/tutorial/images/27humiddew.gif

Psychrometer Instrument used to measure

relative humidity

http://upload.wikimedia.org/wikipedia/commons/0/09/Sling_psychrometer.JPG

Precipitation The falling of liquid or solid water from clouds toward the surface of

Earth

http://www.windows.ucar.edu/earth/images/precipitation.gif

Cloud Cover The fraction or percent of the total sky at a location that is covered by

clouds

Atmospheric Transparency

How transparent the atmosphere is to insolation

Visibility How far you can see along Earth’s

surface expressed in miles

Air Masses and Fronts

Air Mass A large body of air in the troposphere with similar

characteristics of pressure, moisture and temperature

http://www.kidsgeo.com/images/air-masses.jpg

Cyclones

Have low pressure

http://www.mynews.in/News/dailyimage/news/cyclone--430--1.jpg

Cold Front The boundary of an advancing cold air mass and a warmer air

mass, where the underlying cold air pushes forward like a wedge

http://www.uwsp.edu/geo/faculty/ritter/images/atmosphere/weather/cold_front.jpg

Warm Front The boundary of an advancing warm air mass and retreating wedge of cooler air

mass. The cooler air is heavier, the warm air mass is forced to rise as it

advances

http://images.google.com/imgres?imgurl=http://www.physicalgeography.net/fundamentals/images/warmfront.GIF&imgrefurl=http://www.physicalgeography.net/fundamentals/7r.html&usg=__csBKCc0ogNKYd8c7lPrpD1VDD00=&h=325&w=594&sz=27&hl=en&start=1&um=1&itbs=1&tbnid=ICEirI7Rq4Em3M:&tbnh=74&tbnw=135&prev=/images%3Fq%3Dwarm%2Bfront%26um%3D1%26hl%3Den%26safe%3Dactive%26rlz%3D1T4GZAZ_enUS316US317%26tbs%3Disch:1

Occluded Front Boundary of opposing wedges of cold air masses formed when a

cold front overtakes a warm front, lifting the warm air mass off the

ground

http://images.google.com/imgres?imgurl=http://www.physicalgeography.net/fundamentals/images/warmfront.GIF&imgrefurl=http://www.physicalgeography.net/fundamentals/7r.html&usg=__csBKCc0ogNKYd8c7lPrpD1VDD00=&h=325&w=594&sz=27&hl=en&start=7&um=1&itbs=1&tbnid=ICEirI7Rq4Em3M:&tbnh=74&tbnw=135&prev=/images%3Fq%3Doccluded%2Bfront%26um%3D1%26hl%3Den%26safe%3Dactive%26rlz%3D1T4GZAZ_enUS316US317%26tbs%3Disch:1