戈夫-格雷奇方程式

戈夫-格雷奇方程式（英语：Goff-Gratch equation）可以在给定温度的情况下用来确定水的饱和蒸汽压。另一个类似的方程是Arden Buck方程式。

历史

戈夫-格雷奇方程式是以它的两个作者戈夫（Goff）和格雷奇（Gratch）命名，他们在文章里介绍了在某个温度下，如何计算平静的水面上水的饱和蒸汽压。戈夫在1957年修订了这个方程，1988年戈夫-格雷奇方程式被世界气象组织所推荐，2000年又进行了进一步修正。

原始的戈夫-格雷奇方程式(1946) 如下:

$\log \ e^{*}\ =$	$-7.90298(T_{\mathrm {st} }/T-1)\ +\ 5.02808\ \log(T_{\mathrm {st} }/T)$
	$-\ 1.3816\times 10^{-7}(10^{11.344(1-T/T_{\mathrm {st} })}-1)$
	$+\ 8.1328\times 10^{-3}(10^{-3.49149(T_{\mathrm {st} }/T-1)}-1)\ +\ \log \ e_{\mathrm {st} }^{*}$

其中:

log 是以10为底的对数

T_st是沸点温度(373.15 K)

e^*_st 是沸点压力(1 atm = 1013.25 hPa)

在冰面上方，水的饱和蒸汽压可简化为：

$\log \ e_{i}^{*}\ =$	$-9.09718(T_{0}/T-1)\ -\ 3.56654\ \log(T_{0}/T)$
	$+\ 0.876793(1-T/T_{0})+\ \log \ e_{i0}^{*}$

其中:

log 是以10为底的对数

e^*_i 在冰面上方水的饱和蒸汽压(hPa)

T 是空气温度(K)

T₀ 是冰点温度(273.16 K)

e^*_i0 是冰点压力(6.1173 hPa)

Goff, J. A., and Gratch, S. (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.
WMO Guide To Meteorological Instruments and Methods of Observation (the CIMO Guide). 2014 [2023-04-04]. WMO-No. 8. （原始内容存档于2021-04-27）.
Murphy, D.M.; Koop, T. Review of the vapour pressures of ice and supercooled water for atmospheric applications. Quarterly Journal of the Royal Meteorological Society. 2005, 131 (608): 1539–65 [2023-04-04]. Bibcode:2005QJRMS.131.1539M. doi:10.1256/qj.04.94. （原始内容存档于2020-08-18）.