en>Spinningspark: +cat and some cleanup

2014-10-16T22:03:07Z

+cat and some cleanup

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	~~The '''Goff–Gratch equation''' is one (arguably the first reliable) amongst many equations that have been proposed to estimate the~~ [~~[Vapour pressure of water\|saturation water vapor pressure]] at a given temperature.~~		certified psychics - [http://www.sirudang.com/siroo_Notice/2110 http://www.sirudang.com/siroo_Notice/2110] - Hi there. My name is Sophia Meagher although it is not the title on my beginning certificate. For many years she's been operating as a travel agent. My wife and I reside in Mississippi and I love every working day residing right here. The favorite hobby for him and his children is to play lacross and he would never give cheap psychic readings ([http://203.250.78.160/zbxe/?document_srl=1792908 203.250.78.160]) it up.<br><br>my web site :: online psychic reading ([http://www.prograd.uff.br/novo/facts-about-growing-greater-organic-garden http://www.prograd.uff.br/novo/facts-about-growing-greater-organic-garden])

	~~Another similar equation based on more recent data is the [[Arden Buck equation]]~~.

	~~==Historical note==~~

	This equation is named after the authors of the original scientific article who described how to calculate the saturation water vapor pressure above a flat free water surface as a function of temperature (Goff and Gratch, 1946). Goff (1957) later revised his formula, and the latter was recommended for use by the [[World Meteorological Organization]] in 1988, with further corrections in 2000. {{Citation needed\|date=October 2011}}

	~~==Equations==~~

	~~The original Goff–Gratch (1946) equation reads as follows:~~

	~~:{\|~~
	\|-
	~~\|<math>\log\ e^*\ = <~~/~~math>~~
	~~\|<math>-7.90298(T_\mathrm{st}~~/~~T-1)\ +\ 5.02808\ \log(T_\mathrm{st}~~/~~T)<~~/~~math>~~
	\|-
	\|
	~~\|<math>-\ 1~~.~~3816\times10^{-7}(10^{11~~.~~344(1-T~~/~~T_\mathrm{st})}-1)<~~/~~math>~~
	\|
	\|-
	\|
	~~\|<math>+\ 8~~.~~1328\times10^{-3}(10^{-3~~.~~49149(T_\mathrm{st}/T-1)}-1)\ +\ \log\ e^*_\mathrm{st}</math>~~
	\|}

	~~where:~~
	~~:log refers to the logarithm~~ in ~~base 10~~
	~~:''e''<sup>*</sup>~~ is ~~the saturation water vapor pressure~~ ([~~[Pascal (unit)\|hPa]])~~
	:~~''T'' is the [[absolute temperature\|absolute air temperature]] in [[kelvin]]s~~
	~~:''T''<sub>st<~~/~~sub> is the steam-point (i~~.~~e. [[boiling point]] at 1 atm~~.~~) temperature (373~~.~~15 K)~~
	~~:''e''<sup><~~/~~sup><sub>st<~~/~~sub> is e<sup></sup> at the steam-point pressure (1 atm~~ = ~~1013~~.~~25 hPa)~~

	~~Similarly, the equation for the saturation water vapor pressure over ice is:~~

	~~:{\|~~
	\|-
	~~\|<math>\log\ e^*_i\ = </math>~~
	~~\|<math>-9~~.~~09718(T_0/T-1)\ -\ 3~~.~~56654\ \log(T_0/T~~)~~</math>~~
	\|-
	\|
	~~\|<math>+\ 0~~.~~876793(1-T/T_0) +\ \log\ e^*_{i0}~~<~~/math~~>
	\|}

	~~where:~~
	~~:log stands for the logarithm in base 10~~
	~~:''e''~~<~~sup~~>*</sup><sub>i</sub> is the saturation water vapor pressure over ice (hPa)
	:~~''T'' is the air temperature (K)~~
	:~~''T''<sub>0</sub> is the ice-point~~ ([~~[triple point]]) temperature (273.16 K)~~
	:~~''e''<sup><~~/~~sup><sub>i0<~~/~~sub> is e<sup></sup> at the ice-point pressure (6~~.~~1173 hPa)~~

	~~==References==~~

	* Goff, J. A.~~, and S. Gratch (1946) Low~~-pressure properties of water from −160 to 212 °F, in Transactions of the American Society of Heating and Ventilating Engineers, pp 95–122, presented at the 52nd annual meeting of the American Society of Heating and Ventilating Engineers, New York, 1946.

	* Goff, J. A. (1957) Saturation pressure of water on the new Kelvin temperature scale, Transactions of the American Society of Heating and Ventilating Engineers, pp 347–354, presented at the semi-~~annual meeting of the American Society of Heating and Ventilating Engineers, Murray Bay, Que. Canada.~~

	* World Meteorological Organization (1988) General meteorological standards and recommended practices, Appendix A, WMO Technical Regulations, WMO-~~No. 49.~~

	* World Meteorological Organization (2000) General meteorological standards and recommended practices, Appendix A, WMO Technical Regulations, WMO-~~No. 49, corrigendum.~~

	* Murphy, D. M. and Koop, T. (2005): Review of the vapour pressures of ice and supercooled water for atmospheric applications, Quarterly Journal of the Royal Meteorological Society 131(608): 1539–1565. {{doi\|10.1256/qj.04.94}}

	~~==External links==~~
	* http://~~cires~~.~~colorado~~.~~edu/~voemel/vp~~.~~html~~
	* [http://~~www.phymetrix.com/Software.htm Free Windows Program, Moisture Units Conversion Calculator w/Goff~~-~~Gratch equation]~~ - ~~PhyMetrix~~

	~~==See also==~~
	*[[Vapour pressure of water]]
	*[[Antoine equation]]
	*[[Arden Buck equation]]

	~~{{DEFAULTSORT:Goff~~-~~Gratch equation}}~~
	~~[[Category:Atmospheric thermodynamics]~~]

en>Glacialfox: Reverted edits by 84.100.161.10 to last version by Kmarinas86 (GLOO)

2012-01-11T18:37:12Z

Reverted edits by 84.100.161.10 to last version by Kmarinas86 (GLOO)

New page

The '''Goff–Gratch equation''' is one (arguably the first reliable) amongst many equations that have been proposed to estimate the [[Vapour pressure of water|saturation water vapor pressure]] at a given temperature.

Another similar equation based on more recent data is the [[Arden Buck equation]].

==Historical note==

This equation is named after the authors of the original scientific article who described how to calculate the saturation water vapor pressure above a flat free water surface as a function of temperature (Goff and Gratch, 1946). Goff (1957) later revised his formula, and the latter was recommended for use by the [[World Meteorological Organization]] in 1988, with further corrections in 2000. {{Citation needed|date=October 2011}}

==Equations==

The original Goff–Gratch (1946) equation reads as follows:

:{|
|-
|<math>\log\ e^*\ = </math>
|<math>-7.90298(T_\mathrm{st}/T-1)\ +\ 5.02808\ \log(T_\mathrm{st}/T)</math>
|-
|
|<math>-\ 1.3816\times10^{-7}(10^{11.344(1-T/T_\mathrm{st})}-1)</math>
|
|-
|
|<math>+\ 8.1328\times10^{-3}(10^{-3.49149(T_\mathrm{st}/T-1)}-1)\ +\ \log\ e^*_\mathrm{st}</math>
|}

where:
:log refers to the logarithm in base 10
:''e''* is the saturation water vapor pressure ([[Pascal (unit)|hPa]])
:''T'' is the [[absolute temperature|absolute air temperature]] in [[kelvin]]s
:''T''st is the steam-point (i.e. [[boiling point]] at 1 atm.) temperature (373.15 K)
:''e''*st is e* at the steam-point pressure (1 atm = 1013.25 hPa)

Similarly, the equation for the saturation water vapor pressure over ice is:

:{|
|-
|<math>\log\ e^*_i\ = </math>
|<math>-9.09718(T_0/T-1)\ -\ 3.56654\ \log(T_0/T)</math>
|-
|
|<math>+\ 0.876793(1-T/T_0) +\ \log\ e^*_{i0}</math>
|}

where:
:log stands for the logarithm in base 10
:''e''*i is the saturation water vapor pressure over ice (hPa)
:''T'' is the air temperature (K)
:''T''0 is the ice-point ([[triple point]]) temperature (273.16 K)
:''e''*i0 is e* at the ice-point pressure (6.1173 hPa)

==References==

* Goff, J. A., and S. Gratch (1946) Low-pressure properties of water from −160 to 212 °F, in Transactions of the American Society of Heating and Ventilating Engineers, pp 95–122, presented at the 52nd annual meeting of the American Society of Heating and Ventilating Engineers, New York, 1946.

* Goff, J. A. (1957) Saturation pressure of water on the new Kelvin temperature scale, Transactions of the American Society of Heating and Ventilating Engineers, pp 347–354, presented at the semi-annual meeting of the American Society of Heating and Ventilating Engineers, Murray Bay, Que. Canada.

* World Meteorological Organization (1988) General meteorological standards and recommended practices, Appendix A, WMO Technical Regulations, WMO-No. 49.

* World Meteorological Organization (2000) General meteorological standards and recommended practices, Appendix A, WMO Technical Regulations, WMO-No. 49, corrigendum.

* Murphy, D. M. and Koop, T. (2005): Review of the vapour pressures of ice and supercooled water for atmospheric applications, Quarterly Journal of the Royal Meteorological Society 131(608): 1539–1565. {{doi|10.1256/qj.04.94}}

==External links==
* http://cires.colorado.edu/~voemel/vp.html
* [http://www.phymetrix.com/Software.htm Free Windows Program, Moisture Units Conversion Calculator w/Goff-Gratch equation] - PhyMetrix

==See also==
*[[Vapour pressure of water]]
*[[Antoine equation]]
*[[Arden Buck equation]]

{{DEFAULTSORT:Goff-Gratch equation}}
[[Category:Atmospheric thermodynamics]]

Magnetic capacitance - Revision history

en>Spinningspark: +cat and some cleanup

en>Glacialfox: Reverted edits by 84.100.161.10 to last version by Kmarinas86 (GLOO)