source: palm/trunk/SOURCE/diagnostic_quantities_mod.f90 @ 3231

Last change on this file since 3231 was 3231, checked in by schwenkel, 6 years ago

Bugfix for microphysic scheme = saturation_adjustment

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1!> @file diagnostic_quantities_mod.f90
2!------------------------------------------------------------------------------!
3! This file is part of the PALM model system.
4!
5! PALM is free software: you can redistribute it and/or modify it under the
6! terms of the GNU General Public License as published by the Free Software
7! Foundation, either version 3 of the License, or (at your option) any later
8! version.
9!
10! PALM is distributed in the hope that it will be useful, but WITHOUT ANY
11! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
12! A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
13!
14! You should have received a copy of the GNU General Public License along with
15! PALM. If not, see <http://www.gnu.org/licenses/>.
16!
17! Copyright 1997-2018 Leibniz Universitaet Hannover
18!------------------------------------------------------------------------------!
19!
20! Current revisions:
21! -----------------
22!
23!
24! Former revisions:
25! -----------------
26! $Id: diagnostic_quantities_mod.f90 3231 2018-09-06 11:53:51Z schwenkel $
27! Bugfix for microphysic scheme = 'saturation_adjustment'
28!
29! 3026 2018-05-22 10:30:53Z schwenkel
30! Changed the name specific humidity to mixing ratio, since we are computing
31! mixing ratios.
32!
33! 2839 2018-02-27 09:49:06Z schwenkel
34! Bugfix for Kessler microphysics
35!
36! 2718 2018-01-02 08:49:38Z maronga
37! Corrected "Former revisions" section
38!
39! 2696 2017-12-14 17:12:51Z kanani
40! Change in file header (GPL part)
41!
42! 2608 2017-11-13 14:04:26Z schwenkel
43! Initial revision
44!
45!
46! Description:
47! ------------
48!> This module contains subroutines and functions for the calculation of
49!> diagnostic quantities. Especially moisture quantities such as the saturation
50!> mixining ratio is calculated
51!------------------------------------------------------------------------------!
52MODULE diagnostic_quantities_mod
53 
54
55   USE kinds
56   
57   IMPLICIT NONE
58
59   REAL(wp) ::  alpha   !< correction factor
60   REAL(wp) ::  e_s     !< saturation water vapor pressure
61   REAL(wp) ::  q_s     !< saturation mixing ratio
62   REAL(wp) ::  sat     !< supersaturation
63   REAL(wp) ::  t_l     !< actual temperature
64
65   PRIVATE
66   PUBLIC  e_s, magnus, q_s, sat, supersaturation, t_l
67
68    INTERFACE supersaturation
69       MODULE PROCEDURE supersaturation
70    END INTERFACE supersaturation
71
72 CONTAINS
73 
74!------------------------------------------------------------------------------!
75! Description:
76! ------------
77!> Computation of the diagnostic supersaturation sat, actual liquid water
78!< temperature t_l and saturation water vapor mixing ratio q_s
79!------------------------------------------------------------------------------!
80    SUBROUTINE supersaturation ( i,j,k )
81
82       USE arrays_3d,                                                          &
83           ONLY:  hyp, pt, q, qc, qr
84
85       USE cloud_parameters,                                                   &
86           ONLY:  l_d_cp, l_d_r, t_d_pt       
87
88       USE control_parameters,                                                 &
89           ONLY:  microphysics_kessler, microphysics_sat_adjust                                       
90
91       IMPLICIT NONE
92
93       INTEGER(iwp) ::  i                 !<
94       INTEGER(iwp) ::  j                 !<
95       INTEGER(iwp) ::  k                 !<
96!
97!--    Actual liquid water temperature:
98       t_l = t_d_pt(k) * pt(k,j,i)
99!
100!--    Calculate water vapor saturation pressure
101       e_s = magnus( t_l )
102!
103!--    Computation of saturation mixing ratio:
104       q_s   = 0.622_wp * e_s / ( hyp(k) - e_s )
105!
106!--    Correction factor
107       alpha = 0.622_wp * l_d_r * l_d_cp / ( t_l * t_l )
108!
109!--    Correction of the approximated value
110!--    (see: Cuijpers + Duynkerke, 1993, JAS, 23)
111       q_s   = q_s * ( 1.0_wp + alpha * q(k,j,i) ) / ( 1.0_wp + alpha * q_s )
112!
113!--    Supersaturation:
114!--    Not in case of microphysics_kessler or microphysics_sat_adjust
115!--    since qr is unallocated
116       IF ( .NOT. microphysics_kessler  .AND.                                  & 
117            .NOT.  microphysics_sat_adjust )                                THEN
118          sat   = ( q(k,j,i) - qr(k,j,i) - qc(k,j,i) ) / q_s - 1.0_wp
119       ENDIF
120
121    END SUBROUTINE supersaturation
122
123 
124!------------------------------------------------------------------------------!
125! Description:
126! ------------
127!> This function computes the magnus function (Press et al., 1992).
128!> The magnus formula is needed to calculate the saturation vapor pressure
129!------------------------------------------------------------------------------!
130
131    FUNCTION magnus( temperature )
132
133       IMPLICIT NONE
134
135       REAL(wp)     ::  magnus            !<
136       REAL(wp)     ::  temperature       !<
137
138!
139!--    Saturation vapor pressure at t_l:
140       magnus =  611.2_wp * EXP( 17.62_wp * ( temperature - 273.15_wp ) /      & 
141                                            ( temperature - 29.65_wp  ) )
142
143!        magnus = 610.78_wp * EXP( 17.269_wp * ( temperature - 273.16_wp ) /     &
144!                                              ( temperature - 35.86_wp )        &
145!                                )
146
147    END FUNCTION magnus
148
149
150END MODULE diagnostic_quantities_mod
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