Melt Freeze Metamorphism

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-'''[[Metamorphism]]''' which results from one or (more commonly) more cycles of '''[[melting]]''' followed by refreezing. One sequence of melting conditions followed by '''[[freezing]]''' conditions is called a melt-feeze cycle. This is usually diurnal with melt occuring starting in mid-morning or early aftrenoon and freezing starting when the sun goes down. A period of melt-freeze metamorphism leads to '''[[corn snow]]'''. +[[Image:Snow density.jpg|'''[[Metamorphism]]''' which results from one or (more commonly) more cycles of '''[[melting]]''' followed by refreezing. One sequence of melting conditions followed by '''[[freezing]]''' conditions is called a melt-feeze cycle. This is usually diurnal with melt occuring starting in mid-morning or early aftrenoon and freezing starting when the sun goes down. A period of melt-freeze metamorphism leads to '''[[corn snow]]'''.|thumb|450px]]
-[[Image:Snow density.jpg]]+'''[[Metamorphism]]''' which results from one or (more commonly) more cycles of '''[[melting]]''' followed by refreezing. One sequence of melting conditions followed by '''[[freezing]]''' conditions is called a melt-feeze cycle. This is usually diurnal with melt occuring starting in mid-morning or early aftrenoon and freezing starting when the sun goes down. A period of melt-freeze metamorphism leads to '''[[corn snow]]'''.
As '''[[snow]]''' melts '''[[water]]''' is formed and the force of '''[[gravity]]''' pulls these molecules downward. In route to the ground they refreeze thickening in the middle stratum. During this refreezing process energy is released in the form of latent '''[[heat]]'''. As more water comes down from the surface it creates more heat and brings the entire snow pack column to near equal temperature. The '''[[firnification]]''' of the snow strengthens the '''[[snow pack]]''', due to the bonding of grains of snow. As '''[[snow]]''' melts '''[[water]]''' is formed and the force of '''[[gravity]]''' pulls these molecules downward. In route to the ground they refreeze thickening in the middle stratum. During this refreezing process energy is released in the form of latent '''[[heat]]'''. As more water comes down from the surface it creates more heat and brings the entire snow pack column to near equal temperature. The '''[[firnification]]''' of the snow strengthens the '''[[snow pack]]''', due to the bonding of grains of snow.
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'''[[Snow]]''' around trees and under canopies melts faster due to the reradiation of long wave radiation. As snow gets older particles of impurities (e.g., pine needles, dirt, leaves etc…) accrue within the snow. These darkened objects absorb more short wave radiation causing them to rise in '''[[temperature]]''', also reflecting more long wave '''[[radiation]]'''. '''[[Snow]]''' around trees and under canopies melts faster due to the reradiation of long wave radiation. As snow gets older particles of impurities (e.g., pine needles, dirt, leaves etc…) accrue within the snow. These darkened objects absorb more short wave radiation causing them to rise in '''[[temperature]]''', also reflecting more long wave '''[[radiation]]'''.
-== Also see ==+== '''Also see''' ==
*'''[[Eutectic system]]''' *'''[[Eutectic system]]'''
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*'''[[Sodium chloride]]''' *'''[[Sodium chloride]]'''
-== Reference ==+== '''Reference''' ==
*1 The Snow Life-Cycle [http://www.enm.bris.ac.uk/teaching/projects/2002_03/jb8355/introduction.html] *1 The Snow Life-Cycle [http://www.enm.bris.ac.uk/teaching/projects/2002_03/jb8355/introduction.html]
*2 National Avalanche Center [http://www.avalanche.org/~uac/encyclopedia/melt_freeze_snow.htm] *2 National Avalanche Center [http://www.avalanche.org/~uac/encyclopedia/melt_freeze_snow.htm]

Revision as of 19:00, 10 September 2011

Metamorphism which results from one or (more commonly) more cycles of melting followed by refreezing. One sequence of melting conditions followed by freezing conditions is called a melt-feeze cycle. This is usually diurnal with melt occuring starting in mid-morning or early aftrenoon and freezing starting when the sun goes down. A period of melt-freeze metamorphism leads to corn snow.
Metamorphism which results from one or (more commonly) more cycles of melting followed by refreezing. One sequence of melting conditions followed by freezing conditions is called a melt-feeze cycle. This is usually diurnal with melt occuring starting in mid-morning or early aftrenoon and freezing starting when the sun goes down. A period of melt-freeze metamorphism leads to corn snow.

Metamorphism which results from one or (more commonly) more cycles of melting followed by refreezing. One sequence of melting conditions followed by freezing conditions is called a melt-feeze cycle. This is usually diurnal with melt occuring starting in mid-morning or early aftrenoon and freezing starting when the sun goes down. A period of melt-freeze metamorphism leads to corn snow.

As snow melts water is formed and the force of gravity pulls these molecules downward. In route to the ground they refreeze thickening in the middle stratum. During this refreezing process energy is released in the form of latent heat. As more water comes down from the surface it creates more heat and brings the entire snow pack column to near equal temperature. The firnification of the snow strengthens the snow pack, due to the bonding of grains of snow.

Snow around trees and under canopies melts faster due to the reradiation of long wave radiation. As snow gets older particles of impurities (e.g., pine needles, dirt, leaves etc…) accrue within the snow. These darkened objects absorb more short wave radiation causing them to rise in temperature, also reflecting more long wave radiation.

Also see

Reference

  • 1 The Snow Life-Cycle [1]
  • 2 National Avalanche Center [2]
  • 3 STAYING ALIVE IN AVALANCHE TERRAIN - National Avalanche Center [3]

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