The Difference between Convection & Advection Heat Transfers
If you have ever grabbed the metal handle of pot being heated over a campfire, you have painfully experienced heat transfer. There are four ways in which heat is transferred from one object to another: conduction, radiation, convection and advection.
Heat almost always flows from the higher temperature object to the lower, changing the internal energy of both objects in the process. The primary difference between convection and advection heat transfers is the direction of the exchange.
Convection Heat Transfer
Convection heat transfer involves the transfer of heat through the movement of the medium’s particles. This medium must be a gas or liquid, thereby allowing for movement. Convection always transfers heat in the vertical plane. This movement is driven by variations in the medium’s density and, therefore, buoyancy. Heated particles expand, causing them to decrease in density; these particles become more buoyant than surrounding particles, causing them to rise. As they rise, their heat is transferred to cooler portions of the medium located above them.
Examples of Convection
Convection heat transfer takes place when a pot of water is heated. As the water molecules closest to the heat source warm, they expand. This expansion lowers their density and they begin to rise; this is what causes water in a pot to boil. The atmosphere also provides an example of convection heat transfer. When a packet of air is warmed by solar energy — radiation heat transfer — the air packet expands, lowering its density. This increases its buoyancy and causes it to rise in the atmosphere. This produces an unstable atmosphere with a vertical flow of air.
Advection Heat Transfer
Advection heat transfer differs from convection in that the movement of heat is confined to the horizontal plane. This type of heat transfer is not powered by variations in density, but rather requires an outside force, such as wind or currents, to displace the particles of the medium. As the particles move horizontally into systems that are hotter or colder, heat is transferred.
Examples of Advection
The primary example of advection heat transfer is the movement of meteorological fronts. These fronts represent air masses of cold or warm air that are moved horizontally over the surface by winds; as these air masses encounter warmer or cooler air, heat is exchanged between the systems. Ocean currents are another example of advection heat transfer. Rather than vertically, currents move warm or cold water in horizontal directions. As these waters interact with warmer or cooler areas of water, heat is exchanged between them.
Other Types of Heat Transfer
The remaining types of heat transfers are conduction and radiation. Conduction transfers heat from one object to another with no movement; teat is transferred from molecule to molecule. This type of heat transfer only occurs in solids; the handle of a hot pot is an example of conduction. Radiation heat transfer involves the transfer of heat by electromagnetic waves of energy. An example of radiation is sunlight; when these waves strike other particles, they cause them to vibrate, or warm.
Read more at sciencing.com
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Joseph Olson
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There are two items missing from this heat transfer analysis. Absorption of heat is manifested in materials based on degree of freedom. Rigid materials, solids, respond with a linear coefficient of expansion. Liquids respond by layering called thermocline. Gases respond by vertical convection, either a individual molecules or kinetic waves.
The other transfer involves change of state, Latent Heat of Solidification, Vaporization or Condensation. All of these concepts are beyond the climaclownology indoctrination programs, making debate impossible.
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James McGinn
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Thanks for bringing up this subject, Doug. There are a lot of misconceptions about the nature of flow in the atmosphere. And that is true for both the flow of matter (gasses and liquid water) and the flow of heat. Some of what you say is accurate. Some of it, however, is reflective of the cartoonishly oversimplified model that meteorology (one must never forget that all bozo climatologists were originally trained to be meteorologists) tells us is true through their marketing literature but that they (members of the meteorology cult) won’t personally support or discuss.
Most of the movement matter (gases and liquid water) in earth’s atmosphere is as a result of differential air pressure powering streams through vortices. These vortices, extending for hundred or even thousands of miles, provide a pathway isolated from the friction. This allows our planet to achieve a high degree of thermodynamic equilibrium, making earth a comfortable place to live.
Since meteorologists can’t explain vortices they dismiss them and they distract our attention with reference to notions like convection and advection which are meaningless since they don’t really tell us what is actually happening in the atmosphere. Thunderclouds, for example, have nothing whatsoever to do with convection.
The atmosphere is more complex and works base on principles that don’t have much at all to do with the things you mention in this post. You appear to have just parroted back the absurdly simplistic narrative that meteorologists want to public to buy.
Read this thread to get a semblance of what is really occurring in the atmosphere:
The ‘Missing Link’ of Meteorology’s Theory of Storms
http://www.thunderbolts.info/forum/phpBB3/viewtopic.php?f=10&t=16329
James McGinn / Solving Tornadoes
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