1 | MODULE zdfddm |
---|
2 | !!====================================================================== |
---|
3 | !! *** MODULE zdfddm *** |
---|
4 | !! Ocean physics : double diffusion mixing parameterization |
---|
5 | !!====================================================================== |
---|
6 | #if defined key_zdfddm || defined key_esopa |
---|
7 | !!---------------------------------------------------------------------- |
---|
8 | !! 'key_zdfddm' : double diffusion |
---|
9 | !!---------------------------------------------------------------------- |
---|
10 | !! zdf_ddm : compute the Ks for salinity |
---|
11 | !! zdf_ddm_init : read namelist and control the parameters |
---|
12 | !!---------------------------------------------------------------------- |
---|
13 | !! OPA 9.0 , LOCEAN-IPSL (2005) |
---|
14 | !! $Header$ |
---|
15 | !! This software is governed by the CeCILL licence see modipsl/doc/NEMO_CeCILL.txt |
---|
16 | !!---------------------------------------------------------------------- |
---|
17 | !! * Modules used |
---|
18 | USE oce ! ocean dynamics and tracers variables |
---|
19 | USE dom_oce ! ocean space and time domain variables |
---|
20 | USE zdf_oce ! ocean vertical physics variables |
---|
21 | USE in_out_manager ! I/O manager |
---|
22 | USE lbclnk ! ocean lateral boundary conditions (or mpp link) |
---|
23 | |
---|
24 | IMPLICIT NONE |
---|
25 | PRIVATE |
---|
26 | |
---|
27 | !! * Routine accessibility |
---|
28 | PUBLIC zdf_ddm ! called by step.F90 |
---|
29 | |
---|
30 | !! * Shared module variables |
---|
31 | LOGICAL, PUBLIC, PARAMETER :: lk_zdfddm = .TRUE. !: double diffusive mixing flag |
---|
32 | REAL(wp), PUBLIC, DIMENSION(jpi,jpj,jpk) :: & !: |
---|
33 | avs , & !: salinity vertical diffusivity coeff. at w-point |
---|
34 | rrau !: heat/salt buoyancy flux ratio |
---|
35 | |
---|
36 | !! * Module variables |
---|
37 | REAL(wp) :: & !!! * double diffusive mixing namelist * |
---|
38 | avts = 1.e-4_wp ! maximum value of avs for salt fingering |
---|
39 | |
---|
40 | !! * Substitutions |
---|
41 | # include "vectopt_loop_substitute.h90" |
---|
42 | |
---|
43 | CONTAINS |
---|
44 | |
---|
45 | SUBROUTINE zdf_ddm( kt ) |
---|
46 | !!---------------------------------------------------------------------- |
---|
47 | !! *** ROUTINE zdf_ddm *** |
---|
48 | !! |
---|
49 | !! ** Purpose : Add to the vertical eddy diffusivity coefficient the |
---|
50 | !! effect of salt fingering and diffusive convection. |
---|
51 | !! |
---|
52 | !! ** Method : Diapycnal mixing is increased in case of double |
---|
53 | !! diffusive mixing (i.e. salt fingering and diffusive layering) |
---|
54 | !! following Merryfield et al. (1999). The rate of double diffusive |
---|
55 | !! mixing depend on the buoyancy ratio: Rrau=alpha/beta dk[T]/dk[S] |
---|
56 | !! which is computed in rn2.F |
---|
57 | !! * salt fingering (Schmitt 1981): |
---|
58 | !! for Rrau > 1 and rn2 > 0 : zavfs = avts / ( 1 + (Rrau/hsbfr)^6 ) |
---|
59 | !! for Rrau > 1 and rn2 > 0 : zavfs = O |
---|
60 | !! otherwise : zavft = 0.7 zavs / Rrau |
---|
61 | !! * diffusive layering (Federov 1988): |
---|
62 | !! for 0< Rrau < 1 and rn2 > 0 : zavdt = 1.3635e-6 |
---|
63 | !! * exp( 4.6 exp(-0.54 (1/Rrau-1) ) ) |
---|
64 | !! otherwise : zavdt = 0 |
---|
65 | !! for .5 < Rrau < 1 and rn2 > 0 : zavds = zavdt (1.885 Rrau -0.85) |
---|
66 | !! for 0 < Rrau <.5 and rn2 > 0 : zavds = zavdt 0.15 Rrau |
---|
67 | !! otherwise : zavds = 0 |
---|
68 | !! * update the eddy diffusivity: |
---|
69 | !! avt = avt + zavft + zavdt |
---|
70 | !! avs = avs + zavfs + zavds |
---|
71 | !! avmu, avmv are required to remain at least above avt and avs. |
---|
72 | !! |
---|
73 | !! ** Action : avt, avs : update vertical eddy diffusivity coef. |
---|
74 | !! for temperature and salinity |
---|
75 | !! |
---|
76 | !! References : |
---|
77 | !! Merryfield et al., JPO, 29, 1124-1142, 1999. |
---|
78 | !! History : |
---|
79 | !! ! 00-08 (G. Madec) double diffusive mixing |
---|
80 | !! 8.5 ! 02-06 (G. Madec) F90: Free form and module |
---|
81 | !!---------------------------------------------------------------------- |
---|
82 | !! * Arguments |
---|
83 | INTEGER, INTENT( in ) :: kt ! ocean time-step indexocean time step |
---|
84 | |
---|
85 | !!---------------------------------------------------------------------- |
---|
86 | |
---|
87 | |
---|
88 | IF ( kt == nit000 ) CALL zdf_ddm_init ! Initialization (first time-step only) |
---|
89 | |
---|
90 | |
---|
91 | END SUBROUTINE zdf_ddm |
---|
92 | |
---|
93 | |
---|
94 | SUBROUTINE zdf_ddm_init |
---|
95 | !!---------------------------------------------------------------------- |
---|
96 | !! *** ROUTINE zdf_ddm_init *** |
---|
97 | !! |
---|
98 | !! ** Purpose : Initialization of double diffusion mixing scheme |
---|
99 | !! |
---|
100 | !! ** Method : Read the nammbf namelist and check the parameter values |
---|
101 | !! called by zdf_ddm at the first timestep (nit000) |
---|
102 | !! |
---|
103 | !! History : |
---|
104 | !! 8.5 ! 02-08 (G. Madec) Original code |
---|
105 | !!---------------------------------------------------------------------- |
---|
106 | NAMELIST/namddm/ avts |
---|
107 | !!---------------------------------------------------------------------- |
---|
108 | |
---|
109 | ! Read Namelist namddm : double diffusion mixing scheme |
---|
110 | ! -------------------- |
---|
111 | REWIND ( numnam ) |
---|
112 | READ ( numnam, namddm ) |
---|
113 | |
---|
114 | |
---|
115 | ! Parameter control and print |
---|
116 | ! --------------------------- |
---|
117 | IF(lwp) THEN |
---|
118 | WRITE(numout,*) |
---|
119 | WRITE(numout,*) 'zdf_ddm : double diffusive mixing' |
---|
120 | WRITE(numout,*) '~~~~~~~' |
---|
121 | WRITE(numout,*) ' Namelist namddm : set dd mixing parameter' |
---|
122 | WRITE(numout,*) ' maximum avs for dd mixing avts = ', avts |
---|
123 | WRITE(numout,*) |
---|
124 | ENDIF |
---|
125 | |
---|
126 | END SUBROUTINE zdf_ddm_init |
---|
127 | |
---|
128 | #else |
---|
129 | !!---------------------------------------------------------------------- |
---|
130 | !! Default option : Dummy module No double diffusion |
---|
131 | !!---------------------------------------------------------------------- |
---|
132 | LOGICAL, PUBLIC, PARAMETER :: lk_zdfddm = .FALSE. !: double diffusion flag |
---|
133 | CONTAINS |
---|
134 | SUBROUTINE zdf_ddm( kt ) ! Dummy routine |
---|
135 | WRITE(*,*) 'zdf_ddm: You should not have seen this print! error?', kt |
---|
136 | END SUBROUTINE zdf_ddm |
---|
137 | #endif |
---|
138 | |
---|
139 | !!====================================================================== |
---|
140 | END MODULE zdfddm |
---|