convection
Americannoun
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Physics. the transfer of heat by the circulation or movement of the heated parts of a liquid or gas.
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Meteorology. the vertical transport of atmospheric properties, especially upward (advection ).
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the act of conveying or transmitting.
noun
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a process of heat transfer through a gas or liquid by bulk motion of hotter material into a cooler region Compare conduction
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meteorol the process by which masses of relatively warm air are raised into the atmosphere, often cooling and forming clouds, with compensatory downward movements of cooler air
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geology the slow circulation of subcrustal material, thought to be the mechanism by which tectonic plates are moved
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Current in a fluid caused by uneven distribution of heat. For example, air on a part of the Earth's surface warmed by strong sunlight will be heated by contact with the ground and will expand and flow upward, creating a region of low pressure below it; cooler surrounding air will then flow in to this low pressure region. The air thus circulates by convection, creating winds.
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See Note at conduction
Usage
What is convection? Convection is the transfer of heat by the movement of heated parts of liquids and gases. Convection happens in liquids and gases because, unlike in a solid, molecules are able to freely move.For example, the air molecules in your living room continually move around, all moving at about the same speed. However, if you turn on an electric heater, the air particles close to the heater will get hotter, which means they will have more energy and will move faster. Faster-moving particles are less dense, or lighter, and will flow to the top of the living room. Colder particles are denser and will move down toward the floor when the hot particles move up. This movement of hot air is convection.The cold particles that move toward the floor will now be close to the heater. They, too, will heat up and move faster. And just like the earlier particles, these particles will move up, pushing colder particles down. This cycle is called a convection current or a convection cycle. The cycle will continue until an outside force changes things, such as turning off the heater.
Other Word Forms
- convectional adjective
- convective adjective
Etymology
Origin of convection
First recorded in 1615–25; from Late Latin convectiōn-, stem of convectiō “a bringing together”; equivalent to convect + -ion
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
"In addition to heat and compositional convection, the fluid-like motion of light elements may help power Earth's magnetic engine."
From Science Daily
According to this idea, the planet was capped by a stiff, unmoving outer shell while heat-driven convection took place deeper in the mantle.
From Science Daily
Plasma convection -- the large-scale flow of charged particles within the magnetosphere -- drives many dynamic space phenomena.
From Science Daily
However, decades of helioseismic studies have revealed conflicting information about how these flows behave deep inside the convection zone.
From Science Daily
As the molten iron and nickel slowly cool, they form swirling convection currents in the outer core.
From Science Daily
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.