water_psd

 water_psd returns water clouds particle size distribution

    Returns a vector with a particle size distribution
    n(r)=A*r^c1*exp(-Br^c2)


 FORMAT   [y] = water_psd(LWC,r,rc,c1,c2)
  

 OUT      y is a vector with the particle size distribution [#/m^3/m]

 IN       LWC     liquid water content [g/m^3]
          r       the size vector of the ice particles [m]
          c1      psd parameter
          c2      psd parameter
          rc      characteristic radius

 History: 2005-05-24  Created by Bengt Rydberg

0001 % water_psd returns water clouds particle size distribution
0002 %
0003 %    Returns a vector with a particle size distribution
0004 %    n(r)=A*r^c1*exp(-Br^c2)
0005 %
0006 %
0007 % FORMAT   [y] = water_psd(LWC,r,rc,c1,c2)
0008 %
0009 %
0010 % OUT      y is a vector with the particle size distribution [#/m^3/m]
0011 %
0012 % IN       LWC     liquid water content [g/m^3]
0013 %          r       the size vector of the ice particles [m]
0014 %          c1      psd parameter
0015 %          c2      psd parameter
0016 %          rc      characteristic radius
0017 %
0018 % History: 2005-05-24  Created by Bengt Rydberg
0019 
0020 function [y]=water_psd(LWC,r,rc,c1,c2)
0021 
0022 %min_nargin( 5, nargin );
0023 
0024 B=c1/c2/rc^c2;
0025 A=3*LWC*c2*B^((c1+4)/c2)*1e12/4/pi/gamma((c1+4)/c2);
0026 n=A*((r*1e6).^c1.*exp(-B*(r*1e6).^c2))*1e6;
0027 
0028 y=n;
0029