Meteorology Unit 2 - Energy Transfer and Clouds

Global Winds

Atmospheric Circulation

the large scale movement of air across the globe, forms cells. varies from year to year

Tropical Convective Cells

mid latitude depressions occur chaotically. predictions cannot be made beyond ten days in advance.

Latitudinal Circulation Features

caused by insolation, wind belts are categorized by three cells: Hadley cell feral cell, polar cell

Wind Belt Cells

Hadley cell, Ferrel cell, Polar cell

Hadley Cell

a closed circulation loop which starts at the equator, humid and hot, moist air is warmed, decreases in density and rises, moving poleward the rising air creates a low pressure zone near the equator, as it moves it cools, becoming denser, and descends at about the 30th parallel creating a high pressure area, cycles and begins again, shifts during the summer (north) and winter (south) lots of storms

Trade Winds

also called Easterlies because they blow from the East, created from the warm wind at the bottom of the Hadley Cell, it is shifted to blow from the East (toward the West) by the Coriolis Effect.

Two Forms of Trade Winds

northeasterly trade winds in the northern hemisphere, southeasterly trade winds in the southern hemisphere, they move up

Doldrums

the inter-tropical convergence zone, hugs the equator, where hot air rises and forms in the Hadley Cells on either side, the trade winds meet here and cancel each other, so the air moves up, shifts with the Hadley Cells

Ferrel Cell

driven by the Polar and Hadley cells so it’s a secondary circulation feature, goes in a clockwise motion, powered by the two other cells powered by the sun, the weakest one, we are in the Ferrel cell in the winter, and at the Hadley cell in summer. the ground level air moving north is forced west due to the Coriolis Effect (Westerlies) anti trade winds, major storms

Westerlies

anti trade winds they blow from the West to the East, strongest in the Winter, stronger over water,

Two forms of Anti-Trade Winds

southwest in the northern hemisphere and northwest in southern hemisphere

Polar Cell

cool and dry, air approaches the polar areas and descends creating a cold, dry, high pressure area, no forced movement here, contains polar easterlies

Polar Easterlies

northeast to southwest (north pole) southeast northwest (south pole) weakest of all of them

Polar Vortex

large region of cold rotating air around the polar regions (year round) rotates in the direction of the Earth’s spin, strong during the winter and are self contained, weak during summer, breaking apart causing temperature drops, ozone depletion in the spring (natural process) cold snaps

Sudden Stratospheric Warming event

when the polar vortex completely breaks apart, causing massive temperature drops

Jet Stream 1

narrow bands of strong winds in the upper atmosphere that follow the Sun due to the Earth’s rotation, one between each cell group except the two Hadley cells. one way stream

Subtropical Jet Stream

between Hadley and Ferrel, moves faster than polar jet stream

Polar Jet Stream

between Ferrel and Polar

Jet Stream 2

strongest during winter, shifts toward the equator as winter progresses in the northern hemisphere, the polar region would then expand, and the temperature region moves toward the equator