Global Atmospheric Circulation

Equatorial low

equatorial trough. noun. the quasi-continuous belt of low atmospheric pressure that lies between the subtropical high-pressure belts of the Northern and Southern hemispheres.

Horse Latitudes

a belt of calm air and sea occurring in both the northern and southern hemispheres between the trade winds and the westerlies.

Polar Front

In meteorology, the polar front is the boundary between the polar cell and the Ferrel cell around the 60° latitude in each hemisphere. ... The polar front arises as a result of cold polar air meeting warm tropical air. It is a stationary front as the air masses are not moving against each other.

Polar Highes

Polar High. ... Surface temperatures under the polar highs are the coldest on Earth, with no month having an average temperature above freezing. Regions under the polar high also experience very low levels of precipitation, which leads them to be known as "polar deserts".

Polar Highes

Polar High. From Wikipedia, the free encyclopedia. The polar highs are areas of high atmospheric pressure around the north and south poles; the north polar high being the stronger one because land gains and loses heat more effectively than sea.

Polar Jet Streams

Polar front jet stream, also called polar front jet or midlatitude jet stream, a belt of powerful upper-level winds that sits atop the polar front. The winds are strongest in the tropopause, which is the upper boundary of the troposphere, and move in a generally westerly direction in midlatitudes.

Ferrel Cell

The Ferrel Cell is the average motion of air in the mid-latitudes. It is characterized by sinking air near 30 deg and rising air farther poleward. At the surface, air flowing poleward is deflected to the east by the coriolis force, resulting in westerly surface winds.

Polar Easterlies

The polar easterlies are the dry, cold prevailing winds that blow from the high-pressure areas of the polar highs at the North and South Poles towards low-pressure areas within the Westerlies at high latitudes.

Subtropical Highs

The subtropical ridge, also known as the subtropical high or horse latitudes, is a significant belt of atmospheric high pressure situated around the latitudes of 30°N in the Northern Hemisphere and 30°S in the Southern Hemisphere.

Prevailing westerlies

The westerlies, anti-trades, or prevailing westerlies, are prevailing winds from the west toward the east in the middle latitudes between 30 and 60 degrees latitude. They originate from the high-pressure areas in the horse latitudes and trend towards the poles and steer extratropical cyclones in this general manner.

Hadley Cell

a large-scale atmospheric convection cell in which air rises at the equator and sinks at medium latitudes, typically about 30° north or south.

Intertropical Convergence Zone

a narrow zone near the equator where northern and southern air masses converge, typically producing low atmospheric pressure.

Jet Streams

a narrow, variable band of very strong, predominantly westerly air currents encircling the globe several miles above the earth. There are typically two or three jet streams in each of the northern and southern hemispheres.

Convection Cell

a self-contained convective zone in a fluid in which upward motion of warmer fluid in the center is balanced by downward motion of cooler fluid at the periphery.

Doldrums

a state or period of inactivity, stagnation, or depression.

Trade Winds

a wind blowing steadily toward the equator from the northeast in the northern hemisphere or the southeast in the southern hemisphere, especially at sea. Two belts of trade winds encircle the earth, blowing from the tropical high-pressure belts to the low-pressure zone at the equator.

Subpolar Low

subpolar low pressure belt. A band of low pressure located, in the mean, between 50° and 70° latitude. In the Northern Hemisphere, this belt consists of the Aleutian low and the Icelandic low. In the Southern Hemisphere, it is supposed to exist around the periphery of the Antarctic continent.Feb 20, 2012