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e_eq_ice_mk

PURPOSE ^

E_EQ_ICE_MK Equilibrium water vapor pressure over ice using Murphy and

SYNOPSIS ^

function [e] = e_eq_ice_mk(T)

DESCRIPTION ^

 E_EQ_ICE_MK  Equilibrium water vapor pressure over ice using Murphy and
 Koop 2005 parameterization formula.

 Calculate the equilibrium water vapor pressure over a plane surface
 of ice according to http://cires.colorado.edu/~voemel/vp.html
 The formula (T in K, Ei in hPa converted) for saturation vapor pressure over water is:
 
 (Murphy and Koop, 2005)
 Log(ew) = 54.842763 
                - 6763.22 / T 
                - 4.21 Log(T) 
                + 0.000367*T 
                + Tanh{0.0415 (T - 218.8)} 
                *  (53.878 - 1331.22 / T - 9.44523 Log(T) + 0.014025*T
 with T in [K] and ew in [Pa]
 
 Similarly, the equation for the saturation water vapor pressure over ice is:
 Murphy and Koop, 2005

 Log10(ei) = 9.550426 
             - 5723.265/T 
             + 3.53068 Log10(T) 
             - 0.00728332*T
 with T in [K] and ei in [Pa]
 where:
 log stands for the logarithm in base 10
 ei is the saturation water vapor pressure over ice (hPa)
 T is the air temperature (K)

 References:
 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

 FORMAT   e = e_eq_ice_mk(T)

 OUT       e = Equilibrium water vapor pressure over ice in [Pa].
 IN       T = Temperature in [K].

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

DOWNLOAD ^

e_eq_ice_mk.m

SOURCE CODE ^

0001 % E_EQ_ICE_MK  Equilibrium water vapor pressure over ice using Murphy and
0002 % Koop 2005 parameterization formula.
0003 %
0004 % Calculate the equilibrium water vapor pressure over a plane surface
0005 % of ice according to http://cires.colorado.edu/~voemel/vp.html
0006 % The formula (T in K, Ei in hPa converted) for saturation vapor pressure over water is:
0007 %
0008 % (Murphy and Koop, 2005)
0009 % Log(ew) = 54.842763
0010 %                - 6763.22 / T
0011 %                - 4.21 Log(T)
0012 %                + 0.000367*T
0013 %                + Tanh{0.0415 (T - 218.8)}
0014 %                *  (53.878 - 1331.22 / T - 9.44523 Log(T) + 0.014025*T
0015 % with T in [K] and ew in [Pa]
0016 %
0017 % Similarly, the equation for the saturation water vapor pressure over ice is:
0018 % Murphy and Koop, 2005
0019 %
0020 % Log10(ei) = 9.550426
0021 %             - 5723.265/T
0022 %             + 3.53068 Log10(T)
0023 %             - 0.00728332*T
0024 % with T in [K] and ei in [Pa]
0025 % where:
0026 % log stands for the logarithm in base 10
0027 % ei is the saturation water vapor pressure over ice (hPa)
0028 % T is the air temperature (K)
0029 %
0030 % References:
0031 % Murphy, D. M. and Koop, T. (2005): Review of the vapour pressures of ice
0032 % and supercooled water for atmospheric applications, Quarterly Journal of the
0033 % Royal Meteorological Society 131(608): 1539–1565. doi:10.1256/qj.04.94
0034 %
0035 % FORMAT   e = e_eq_ice_mk(T)
0036 %
0037 % OUT       e = Equilibrium water vapor pressure over ice in [Pa].
0038 % IN       T = Temperature in [K].
0039 
0040 % 2011-02-16 Created by Marston Johnston
0041 
0042 function [e] = e_eq_ice_mk(T)
0043 
0044 if any(T <= 0), error('Temperatures must be greater than 0K!!'); end
0045 
0046 % Give the natural log of saturation vapor pressure over ice in Pa
0047  e = 9.550426... 
0048      - 5723.265./T... 
0049      + 3.53068*log(T)... 
0050      - 0.00728332*T;
0051 
0052 e = exp(e);
0053

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