The TEKSKnow that climatic interactions exist among
Earth, ocean, and weather systems.
• 8.10 (A) recognize that the Sun provides the energy that drives convection within the atmosphere and oceans, producing winds and ocean currents;
CONVECTION
Transfer of heat by the movement of warmed fluid (air or liquid)
Warm fluid rises (less dense)
Cool fluid sinks (more dense)
CONVECTIONMoves air in the atmosphere!
Moving Air = Winds
Convection in the atmosphereis the main cause of the wind.
Where does the Energy for Convection come from onEarth?
Atmospheric Density
What is most dense
SINKS!
How high is the atmosphere? 99% is within 30 km / 18 miles of the surface of the Earth
Half the atmosphere is 5 km / 3.5 miles above the surface of the Earth
Air Pressure – the weight of the air pressing on the surface at a give location
Atmospheric Movement
MOSTLY CAUSED BY:- Temperature differences- Pressure differences- Coriolis Effect (due to Earth’s
rotation)
The TEKSKnow that climatic interactions exist
among Earth, ocean, and weather systems.
• 8.10 (B) identify how global patterns of atmospheric movement influence local weather using weather maps that show high and low pressures and fronts;
Coriolis Effect breaks upGlobal Circulation
• On Earth the large circulation cell breaks up into 3 smaller ones, moving diagonally
• Other worlds have more or fewer circulation cells depending on their rotation rate
The Coriolis effect
• The Coriolis effect– Is a result of Earth’s rotation– Causes moving objects to follow curved paths:
• In Northern Hemisphere, curvature is to right
• In Southern Hemisphere, curvature is to left
– Changes with latitude:• No Coriolis effect at Equator
• Maximum Coriolis effect at poles
The Coriolis effect on Earth
• As Earth rotates, different latitudes travel at different speeds
• The change in speed with latitude causes the Coriolis effect
Figure 6-9a
Role of the Ocean• Slowly absorbs and slowly releases
heat energy helping keep Earth’s temperatures relatively stable
• Oceans heat or cool the air above them and transport heat around the globe in currents.
• Hurricanes form over warm ocean water, drawing their energy from the water’s heat.
Ocean CurrentsCurrents
• large scale water movements– occur everywhere in ocean– both surface and deep
• 2 main types: surface currents (10%) and subsurface currents (90%)– surface currents are primarily wind driven– deep currents are density driven – other forces affecting currents
Coriolis effectfrictiongravitythermal expansiongeologic shape of ocean basin
Gyres are large circular-moving loops of waterFive main gyres (one in each ocean
basin):• North Pacific• South Pacific• North Atlantic• South Atlantic• Indian
• Generally 4 currents in each gyre• Centered about 30o north or south
latitude
Current GyresCurrent Gyres
•January 1992 - shipwrecked in the Pacific Ocean, off the coast of China
•November 1992 - half had drifted north to the Bering Sea and Alaska; the other half went south to Indonesia and Australia
•1995 to 2000 - spent five years in the Arctic ice floes, slowly working their way through the glaciers
•2001 - the duckies bobbed over the place where the Titanic had sunk
•2003 - they were predicted to begin washing up onshore in New England, but only one was spotted in Maine
•2007 - a couple duckies and frogs were found on the beaches of Scotland and southwest England.
Duckie Progress
Other Effects of Wind on Water Movement
a) Downwelling – results when two wind-driven surface currents collideOR when a wind-driven surface current collides with a land mass
two surface currents colliding surface current colliding with land mass
b) Upwelling - results when two wind-driven surface currents move away from each other OR when a wind-driven surface current moves away from a land mass
surface current pushed away from land masstwo surface currents pushed in opposite directions
Surface and Deep-Sea Current Interactions
Unifying concept: “Global Ocean Conveyor Belt”
http://seis.natsci.csulb.edu/rbehl/ConvBelt.htm
Four Types of FrontsCold Fronts A cold front forms when cold air moves underneath warm air, forcing the warm air to rise.
Four Types of Fronts
Warm Fronts - A warm front forms when warm air moves over cold air.
What kind of weather forms at a warm front?
Stationary Fronts
Where the warm and cool air meet, water vapor in the
warm air condenses into rain, snow, fog, or clouds.
Occluded Fronts
When a cold air mass and a cool air mass come
together, the warm air caught between them is
forced upward.
Radar
http://www.crh.noaa.gov/arx/?n=jul2409Local Weather….
http://www.wunderground.com/maps/#?type=Fronts
The TEKSKnow that climatic interactions exist
among Earth, ocean, and weather systems.
• 8.10 (C) identify the role of the oceans in the formation of weather systems such as hurricanes.
http://www.weatherwizkids.com/weather-hurricane.htm
What Happens On Land?
• LandfallAfter a few hours over land, a hurricane will weaken rapidly. WHY?
• Without the moisture and heat sources provided by the ocean, the storm can no longer produce thunderstorms near the eye. Without this convection, the storm's energy dissipates.
Recommended Resources…
• Edheads – Reading a Weather Map Tutorial & Interactive Game• http://edheads.org/activities/weather/index.shtml• Current Weather Maps – (different maps for temp, pressure, moisture, etc)• http://weather.rap.ucar.edu/surface/• Weather - Easy Interactive Barometer• http://kids.earth.nasa.gov/archive/air_pressure/barometer.html• Air Force Association that Flies Into Hurricanes to Collect Data!• http://www.hurricanehunters.com/• Short video clip about their mission
http://oceantoday.noaa.gov/hurricanehunters/welcome.html • NOAA – Education Resources• http://www.education.noaa.gov/• Bill Nye – Storms• http://www.gamequarium.org/cgi-bin/search/linfo.cgi?id=7827
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