Atmospheric Circulation GPH 111 Volcanic debris from Mt
Atmospheric Circulation GPH 111
Volcanic debris from Mt. Pinatubo spreads worldwide - covering 42% of the globe in 60 days
Atmospheric Pressure and Wind w w w Atmospheric Processes The Nature of Wind General Circulation of the Atmosphere Modifications of General Circulation Localized Wind Systems
Atmospheric Processes w Pressure, Density, and Temperature w Mapping Pressure with Isobars
Pressure and Density
More Air Pressure…
What is HIGH pressure, what is LOW pressure? What’s an Isobar?
Global Patterns of Pressure…
Sample Pressures…
How does wind work? w Direction of Movement w Pressure Gradient - Wind speed - Cyclones and Anticyclones w Coriolis Effect - Geostrophic Winds (Pressure and Coriolis) w Friction
Pressure Gradient
Pressure Gradient: High to Low Pressure
Pressure Gradient: (again) High to Low Pressure
High Pressure = Anticyclone Low Pressure = Cyclone
Coriolis Effect… This will bend your brain…
Geostrophic Winds Combined result of pressure gradient and coriolis effect!
The effect of surface friction…
The effect of surface friction… Show movies Overcomes the balance of pressure gradient and coriolis by slowing the wind down.
Just the Pressure Gradient Force Pressure Gradient and Coriolis Forces generate High Altitude Geostrophic Wind Friction Force Extends to a height of about 1, 650 ft
General Circulation of the Atmosphere w Hadley Cells w Components of General Circulation w Jet Streams - Rossby waves
Hadley Cell… The most dominant wind patterns on the planet!!!
General Worldwide Circulation… Components w Subtropical Highs w Trade Winds w Intertropical Convergence Zone w The Westerlies w Polar Highs w Polar Easterlies w Subpolar Lows
Wind Circulation in Profile… High Low
What are Jet Streams? Jet streams form along the upper boundaries of large warm and cold air masses Speeds range between 50 and 300 mph
Consider two side-by-side columns of air, one warm and one cold. If you rise 1, 000 meters in cold air, you would rise above more air molecules than you would in warm air. Translated: pressure falls faster in colder air. Eventually, this change in pressure makes a big difference. At the high altitudes of the jet stream, pressure is much higher in warm air and the warmer, “denser” air pushes toward the cold “thinner” air. The result is wind. This wind is geostrophic at high elevations and parallels the isobars, thus whipping around the planet in the jet streams Jet stream and Pressure
Polar Jet Stream affected by Rossby Waves Important for when we get into Cold and Warm Fronts, show movie
Let’s review this stuff again!
Modifications of General Circulation w Seasonal Variations in Latitude w Monsoons
Seasonal variations in Latitude Show movie!
The Asian Monsoon…
Localized Wind Systems w Sea and Land Breezes
Local Winds: Daytime Sea-Breeze and Night and Land-Breeze Conditions
Things to Know: w Define and describe Air Pressure w World wind patterns, including Hadley Cells, Westerlies, Trade Winds, etc. (DIAGRAM) w Driving forces in the atmosphere including pressure gradient, coriolis, and friction w What a geostrophic wind is and where you find them? w Cyclones and Anticyclones w Jet Streams and Rossby Waves w Local winds: sea-breeze, land breeze w Seasonal circulation variations due to latitude and how this generates the Asian Monsoon Help – Chapter AC
- Slides: 33
