AtmosphericCirculation Patterns Atmospheric Circulation Patterns Ally, Molly, Joe Atmosphere Jigsaw

Pre-assessment (T or F) Q: The atmospheric circulation moves only in vertical motion A: False, There are both vertical and horizontal motions in the atmospheric circulation Q: Air moves high pressure areas to lower pressure areas A: True Click for answer

Wind Created by air moving from high pressure areas, to low- pressure areas, where air is less dense Horizontal winds follow curved trajectories due to the rotation of the earth

Sea Breezes During day coastal land heats up more than the seaDuring day coastal land heats up more than the sea –Air over land is thus warmed and rises, increasing pressure –Starts to cool and form clouds Air then flows from area of high pressure to lower pressure over the sea.Air then flows from area of high pressure to lower pressure over the sea. pressure at the surface is higher at seapressure at the surface is higher at sea –Air then flows in from the sea to the land At night, when land cools more quickly than the ocean, the cycle is reversedAt night, when land cools more quickly than the ocean, the cycle is reversed

Coriolis Force Cause winds that move over long distances appear to curve –A force caused by Earth’s Rotation Different points on planet move at different speeds causing air to move faster in certain areas A parcel’s radius of spin around Earth decreases as it moves closer to Earth's axis of rotation –rate of spin increases The parcel will deflect to the right of its original trajectory due to its high angular velocity –In Southern hem. parcel would appear to deflect left

Coriolis Force makes winds in low-pressure weather systems curve into spirals –Hurricanes As air travels, Coriolis force bends its course toward a state called geostrophic flow –pressure gradient force and Coriolis force exactly balance each other

In the northern hemisphere… High pressure region develops pressure force directed away from the high. High pressure region develops pressure force directed away from the high. Air starting to move in response to this force is deflected to the right = clockwise circulation pattern around a region of high pressureAir starting to move in response to this force is deflected to the right = clockwise circulation pattern around a region of high pressure A low-pressure region develops, pressure forces air from outside toward the low. A low-pressure region develops, pressure forces air from outside toward the low. Air that moves because of the force is deflected to the right and rotates counter-clockwise around the system.Air that moves because of the force is deflected to the right and rotates counter-clockwise around the system.

Air will spiral into low pressure areas near the surface then rise once they reach the center. Air will spiral into low pressure areas near the surface then rise once they reach the center. As air rises, it cools, producing condensation, clouds, and rain. As air rises, it cools, producing condensation, clouds, and rain. Air will spiral away from high pressure areas near surface toward low pressure areas. Air will spiral away from high pressure areas near surface toward low pressure areas. –To maintain barometric balance, air will descend from above. When wind speed declines…

A general circulation of the atmosphere was presented in 1735 by English meteorologist George Hadley Model shows  warm air rising over the equator and sinking over the poles  simple circulation, upwelling near the equator and descending in polar regions in reality circulation ends at a latitude of about 30°  air sinks to the ground and flows back to the tropics produces easterly winds near surface at low latitudes and westerly winds at high latitudes  Farther north and south, this pattern repeats in two more sets of circulation zones between tropics and poles

Post-assessment Q: During the day air flows move _______ to _______, at night it flows ______ to _______ A) the sea to the land; the land to the sea B) the land to sea; the sea to the land A: A) the sea to the land; the land to the sea Q: Because of the Coriolis force, to which direction does air moving from lower to higher latitude deflect? (in Northern Hemisphere) A: to the right Q: High pressure produces ________ circulation pattern around the region, whereas low pressure produces _________ circulation pattern. A: Clockwise; Counterclockwise Q: Which pressure area will result in producing clouds and rain? High or low? A: Low pressure area Click for answer