1 | MODULE stpmlf |
---|
2 | !!====================================================================== |
---|
3 | !! *** MODULE stpMLF *** |
---|
4 | !! Time-stepping : manager of the shallow water equation time stepping |
---|
5 | !! Modified Leap Frog scheme |
---|
6 | !!====================================================================== |
---|
7 | !! History : NEMO ! 2020-03 (A. Nasser, G. Madec) Original code from 4.0.2 |
---|
8 | !! - ! 2020-10 (S. Techene, G. Madec) cleanning |
---|
9 | !!---------------------------------------------------------------------- |
---|
10 | |
---|
11 | !!---------------------------------------------------------------------- |
---|
12 | !! stp_MLF : MLF Shallow Water Eq. time-stepping |
---|
13 | !!---------------------------------------------------------------------- |
---|
14 | USE stp_oce ! modules used in nemo_init and stp_MLF |
---|
15 | ! |
---|
16 | USE domqco ! quasi-eulerian coordinate |
---|
17 | USE phycst ! physical constants |
---|
18 | USE usrdef_nam ! user defined namelist parameters |
---|
19 | !!st USE usrdef_sbc ! user defined surface boundary cond |
---|
20 | |
---|
21 | IMPLICIT NONE |
---|
22 | PRIVATE |
---|
23 | |
---|
24 | PUBLIC stp_MLF ! called by nemogcm.F90 |
---|
25 | |
---|
26 | ! !** time level indices **! |
---|
27 | INTEGER, PUBLIC :: Nbb, Nnn, Naa, Nrhs !: used by nemo_init |
---|
28 | |
---|
29 | !! * Substitutions |
---|
30 | # include "do_loop_substitute.h90" |
---|
31 | # include "domzgr_substitute.h90" |
---|
32 | !!---------------------------------------------------------------------- |
---|
33 | !! NEMO/OCE 4.0 , NEMO Consortium (2018) |
---|
34 | !! $Id: step.F90 12614 2020-03-26 14:59:52Z gm $ |
---|
35 | !! Software governed by the CeCILL license (see ./LICENSE) |
---|
36 | !!---------------------------------------------------------------------- |
---|
37 | CONTAINS |
---|
38 | |
---|
39 | SUBROUTINE stp_MLF( kstp ) |
---|
40 | !!---------------------------------------------------------------------- |
---|
41 | !! *** ROUTINE stp_MLF *** |
---|
42 | !! |
---|
43 | !! ** Purpose : - Time stepping of shallow water (SHW) (momentum and ssh eqs.) |
---|
44 | !! |
---|
45 | !! ** Method : -1- Update forcings |
---|
46 | !! -2- Update the ssh at Naa |
---|
47 | !! -3- Compute the momentum trends (Nrhs) |
---|
48 | !! -4- Update the horizontal velocity |
---|
49 | !! -5- Apply Asselin time filter to uu,vv,ssh |
---|
50 | !! -6- Outputs and diagnostics |
---|
51 | !!---------------------------------------------------------------------- |
---|
52 | INTEGER, INTENT(in) :: kstp ! ocean time-step index |
---|
53 | ! |
---|
54 | INTEGER :: ji, jj, jk ! dummy loop indices |
---|
55 | INTEGER :: indic ! error indicator if < 0 |
---|
56 | REAL(wp):: z1_2rho0 ! local scalars |
---|
57 | REAL(wp):: zrhs_u, zue3a, zue3n, zue3b, zua ! local scalars |
---|
58 | REAL(wp):: zrhs_v, zve3a, zve3n, zve3b, zva ! - - |
---|
59 | !! --------------------------------------------------------------------- |
---|
60 | ! |
---|
61 | IF( ln_timing ) CALL timing_start('stp_MLF') |
---|
62 | ! |
---|
63 | !>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> |
---|
64 | ! model timestep |
---|
65 | !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< |
---|
66 | ! |
---|
67 | IF( l_1st_euler ) THEN ! start or restart with Euler 1st time-step |
---|
68 | rDt = rn_Dt |
---|
69 | r1_Dt = 1._wp / rDt |
---|
70 | ENDIF |
---|
71 | |
---|
72 | IF( kstp == nit000 ) ww(:,:,:) = 0._wp ! initialize vertical velocity once for all to zero |
---|
73 | |
---|
74 | ! |
---|
75 | !>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> |
---|
76 | ! update I/O and calendar |
---|
77 | !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< |
---|
78 | indic = 0 ! reset to no error condition |
---|
79 | |
---|
80 | IF( kstp == nit000 ) THEN ! initialize IOM context (must be done after nemo_init for AGRIF+XIOS+OASIS) |
---|
81 | CALL iom_init( cxios_context, ld_closedef=.FALSE. ) ! for model grid (including passible AGRIF zoom) |
---|
82 | CALL iom_init_closedef |
---|
83 | ENDIF |
---|
84 | IF( kstp /= nit000 ) CALL day( kstp ) ! Calendar (day was already called at nit000 in day_init) |
---|
85 | CALL iom_setkt( kstp - nit000 + 1, cxios_context ) ! tell IOM we are at time step kstp |
---|
86 | |
---|
87 | !>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> |
---|
88 | ! Update external forcing (SWE: surface boundary condition only) |
---|
89 | !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< |
---|
90 | |
---|
91 | CALL sbc ( kstp, Nbb, Nnn ) ! Sea Boundary Condition |
---|
92 | |
---|
93 | !>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> |
---|
94 | ! Ocean physics update (SWE: eddy viscosity only) |
---|
95 | !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< |
---|
96 | |
---|
97 | IF( l_ldfdyn_time ) CALL ldf_dyn( kstp, Nbb ) ! eddy viscosity coeff. |
---|
98 | |
---|
99 | !>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> |
---|
100 | ! RHS of horizontal velocity |
---|
101 | !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< |
---|
102 | |
---|
103 | uu(:,:,:,Nrhs) = 0._wp ! set dynamics trends to zero |
---|
104 | vv(:,:,:,Nrhs) = 0._wp |
---|
105 | |
---|
106 | CALL dyn_adv( kstp, Nbb, Nnn, uu, vv, Nrhs ) ! advection (VF or FF) ==> RHS |
---|
107 | CALL dyn_vor( kstp, Nnn, uu, vv, Nrhs ) ! vorticity ==> RHS |
---|
108 | CALL dyn_ldf( kstp, Nbb, Nnn, uu, vv, Nrhs ) ! lateral mixing ==> RHS |
---|
109 | |
---|
110 | z1_2rho0 = 0.5_wp * r1_rho0 |
---|
111 | ! |
---|
112 | DO_3D( 0, 0, 0, 0, 1, jpkm1 ) |
---|
113 | ! ! horizontal pressure gradient |
---|
114 | zrhs_u = - grav * ( ssh(ji+1,jj,Nnn) - ssh(ji,jj,Nnn) ) * r1_e1u(ji,jj) |
---|
115 | zrhs_v = - grav * ( ssh(ji,jj+1,Nnn) - ssh(ji,jj,Nnn) ) * r1_e2v(ji,jj) |
---|
116 | ! ! wind stress and layer friction |
---|
117 | zrhs_u = zrhs_u + z1_2rho0 * ( utau_b(ji,jj) + utau(ji,jj) ) / e3u(ji,jj,jk,Nnn) & |
---|
118 | & - rn_rfr * uu(ji,jj,jk,Nbb) |
---|
119 | zrhs_v = zrhs_v + z1_2rho0 * ( vtau_b(ji,jj) + vtau(ji,jj) ) / e3v(ji,jj,jk,Nnn) & |
---|
120 | & - rn_rfr * vv(ji,jj,jk,Nbb) |
---|
121 | ! ! ==> RHS |
---|
122 | uu(ji,jj,jk,Nrhs) = uu(ji,jj,jk,Nrhs) + zrhs_u |
---|
123 | vv(ji,jj,jk,Nrhs) = vv(ji,jj,jk,Nrhs) + zrhs_v |
---|
124 | END_3D |
---|
125 | |
---|
126 | !>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> |
---|
127 | ! Time stepping of ssh Eq. (and update r3_Naa) |
---|
128 | !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< |
---|
129 | ! ! Leap Frog time stepping ==> ssh_Naa and r3_Naa |
---|
130 | CALL ssh_nxt( kstp, Nbb, Nnn, ssh , Naa ) ! after ssh |
---|
131 | ! ! after ssh/h_0 ratio explicit |
---|
132 | CALL dom_qco_r3c( ssh(:,:,Naa), r3t(:,:,Naa), r3u(:,:,Naa), r3v(:,:,Naa), r3f(:,:) ) |
---|
133 | ! ! Asselin filter ==> ssh_Nnn filtered |
---|
134 | IF ( .NOT.( l_1st_euler ) ) THEN ! Time filtering of now ssh |
---|
135 | ssh(:,:,Nnn) = ssh(:,:,Nnn) + rn_atfp * ( ssh(:,:,Nbb) - 2._wp * ssh(:,:,Nnn) + ssh(:,:,Naa) ) |
---|
136 | ENDIF |
---|
137 | |
---|
138 | !>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> |
---|
139 | ! Time stepping of dynamics (u,v) |
---|
140 | !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< |
---|
141 | |
---|
142 | IF( ln_dynadv_vec ) THEN ! vector invariant form : applied on velocity |
---|
143 | IF( l_1st_euler ) THEN ! Euler time stepping (no Asselin filter) |
---|
144 | DO_3D( 0,0, 0,0, 1,jpkm1) |
---|
145 | uu(ji,jj,jk,Naa) = uu(ji,jj,jk,Nbb) + rDt * uu(ji,jj,jk,Nrhs) * umask(ji,jj,jk) |
---|
146 | vv(ji,jj,jk,Naa) = vv(ji,jj,jk,Nbb) + rDt * vv(ji,jj,jk,Nrhs) * vmask(ji,jj,jk) |
---|
147 | END_3D |
---|
148 | ELSE ! Leap Frog time stepping + Asselin filter |
---|
149 | DO_3D( 0,0, 0,0, 1,jpkm1) |
---|
150 | zua = uu(ji,jj,jk,Nbb) + rDt * uu(ji,jj,jk,Nrhs) * umask(ji,jj,jk) |
---|
151 | zva = vv(ji,jj,jk,Nbb) + rDt * vv(ji,jj,jk,Nrhs) * vmask(ji,jj,jk) |
---|
152 | ! ! Asselin time filter on u,v (Nnn) |
---|
153 | uu(ji,jj,jk,Nnn) = uu(ji,jj,jk,Nnn) + rn_atfp * (uu(ji,jj,jk,Nbb) - 2._wp * uu(ji,jj,jk,Nnn) + zua) |
---|
154 | vv(ji,jj,jk,Nnn) = vv(ji,jj,jk,Nnn) + rn_atfp * (vv(ji,jj,jk,Nbb) - 2._wp * vv(ji,jj,jk,Nnn) + zva) |
---|
155 | ! |
---|
156 | uu(ji,jj,jk,Naa) = zua |
---|
157 | vv(ji,jj,jk,Naa) = zva |
---|
158 | END_3D |
---|
159 | ! ! Update r3_Nnn |
---|
160 | CALL dom_qco_r3c( ssh(:,:,Nnn), r3t(:,:,Nnn), r3u(:,:,Nnn), r3v(:,:,Nnn) ) ! now ssh/h_0 ratio from filtrered ssh |
---|
161 | ENDIF |
---|
162 | ! |
---|
163 | ELSE ! flux form : applied on thickness weighted velocity |
---|
164 | IF( l_1st_euler ) THEN ! Euler time stepping (no Asselin filter) |
---|
165 | DO_3D( 0,0, 0,0, 1,jpkm1) |
---|
166 | zue3b = e3u(ji,jj,jk,Nbb) * uu(ji,jj,jk,Nbb) |
---|
167 | zve3b = e3v(ji,jj,jk,Nbb) * vv(ji,jj,jk,Nbb) |
---|
168 | ! ! Euler time stepping |
---|
169 | zue3a = zue3b + rDt * e3u(ji,jj,jk,Nnn) * uu(ji,jj,jk,Nrhs) * umask(ji,jj,jk) |
---|
170 | zve3a = zve3b + rDt * e3v(ji,jj,jk,Nnn) * vv(ji,jj,jk,Nrhs) * vmask(ji,jj,jk) |
---|
171 | ! |
---|
172 | uu(ji,jj,jk,Naa) = zue3a / e3u(ji,jj,jk,Naa) |
---|
173 | vv(ji,jj,jk,Naa) = zve3a / e3v(ji,jj,jk,Naa) |
---|
174 | END_3D |
---|
175 | ELSE ! Leap Frog time stepping + Asselin filter |
---|
176 | CALL dom_qco_r3c( ssh(:,:,Nnn), r3t_f(:,:), r3u_f(:,:), r3v_f(:,:) ) ! now ssh/h_0 ratio from filtrered ssh |
---|
177 | DO_3D( 0,0, 0,0, 1,jpkm1) |
---|
178 | zue3n = ( 1._wp + r3u(ji,jj,Nnn) ) * uu(ji,jj,jk,Nnn) |
---|
179 | zve3n = ( 1._wp + r3v(ji,jj,Nnn) ) * vv(ji,jj,jk,Nnn) |
---|
180 | zue3b = ( 1._wp + r3u(ji,jj,Nbb) ) * uu(ji,jj,jk,Nbb) |
---|
181 | zve3b = ( 1._wp + r3v(ji,jj,Nbb) ) * vv(ji,jj,jk,Nbb) |
---|
182 | ! ! LF time stepping |
---|
183 | zue3a = zue3b + rDt * ( 1._wp + r3u(ji,jj,Nnn) ) * uu(ji,jj,jk,Nrhs) * umask(ji,jj,jk) |
---|
184 | zve3a = zve3b + rDt * ( 1._wp + r3v(ji,jj,Nnn) ) * vv(ji,jj,jk,Nrhs) * vmask(ji,jj,jk) |
---|
185 | ! ! Asselin time filter on u,v (Nnn) |
---|
186 | uu(ji,jj,jk,Nnn) = ( zue3n + rn_atfp * ( zue3b - 2._wp * zue3n + zue3a ) ) / ( 1._wp + r3u_f(ji,jj) ) |
---|
187 | vv(ji,jj,jk,Nnn) = ( zve3n + rn_atfp * ( zve3b - 2._wp * zve3n + zve3a ) ) / ( 1._wp + r3v_f(ji,jj) ) |
---|
188 | ! |
---|
189 | uu(ji,jj,jk,Naa) = zue3a / ( 1._wp + r3u(ji,jj,Naa) ) |
---|
190 | vv(ji,jj,jk,Naa) = zve3a / ( 1._wp + r3v(ji,jj,Naa) ) |
---|
191 | END_3D |
---|
192 | ! ! Update r3_Nnn with time filtered values |
---|
193 | r3t(:,:,Nnn) = r3t_f(:,:) |
---|
194 | r3u(:,:,Nnn) = r3u_f(:,:) |
---|
195 | r3v(:,:,Nnn) = r3v_f(:,:) |
---|
196 | ENDIF |
---|
197 | ENDIF |
---|
198 | |
---|
199 | CALL lbc_lnk_multi( 'stp_MLF', uu(:,:,:,Nnn), 'U', -1., vv(:,:,:,Nnn), 'V', -1., & !* local domain boundaries |
---|
200 | & uu(:,:,:,Naa), 'U', -1., vv(:,:,:,Naa), 'V', -1. ) |
---|
201 | |
---|
202 | !>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> |
---|
203 | ! Set boundary conditions, time filter and swap time levels |
---|
204 | !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< |
---|
205 | |
---|
206 | ! Swap time levels |
---|
207 | Nrhs = Nbb |
---|
208 | Nbb = Nnn |
---|
209 | Nnn = Naa |
---|
210 | Naa = Nrhs |
---|
211 | |
---|
212 | !>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> |
---|
213 | ! diagnostics and outputs |
---|
214 | !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< |
---|
215 | |
---|
216 | IF( ln_diacfl ) CALL dia_cfl ( kstp, Nnn ) ! Courant number diagnostics |
---|
217 | CALL dia_wri ( kstp, Nnn ) ! ocean model: outputs |
---|
218 | ! |
---|
219 | IF( lrst_oce ) CALL rst_write( kstp, Nbb, Nnn ) ! write output ocean restart file |
---|
220 | |
---|
221 | !>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> |
---|
222 | ! Control |
---|
223 | !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< |
---|
224 | CALL stp_ctl_SWE ( kstp, Nnn ) |
---|
225 | |
---|
226 | IF( kstp == nit000 ) THEN ! 1st time step only |
---|
227 | CALL iom_close( numror ) ! close input ocean restart file |
---|
228 | IF(lwm) CALL FLUSH ( numond ) ! flush output namelist oce |
---|
229 | IF(lwm .AND. numoni /= -1 ) CALL FLUSH ( numoni ) ! flush output namelist ice (if exist) |
---|
230 | ENDIF |
---|
231 | |
---|
232 | ! |
---|
233 | #if defined key_iomput |
---|
234 | IF( kstp == nitend .OR. indic < 0 ) THEN |
---|
235 | !!st : cxios_context needed ? because opened earlier ??? |
---|
236 | CALL iom_context_finalize( cxios_context ) ! needed for XIOS+AGRIF |
---|
237 | ENDIF |
---|
238 | #endif |
---|
239 | ! |
---|
240 | IF( l_1st_euler ) THEN ! recover Leap-frog timestep |
---|
241 | rDt = 2._wp * rn_Dt |
---|
242 | r1_Dt = 1._wp / rDt |
---|
243 | l_1st_euler = .FALSE. |
---|
244 | ENDIF |
---|
245 | ! |
---|
246 | IF( ln_timing ) CALL timing_stop('stp_MLF') |
---|
247 | ! |
---|
248 | END SUBROUTINE stp_MLF |
---|
249 | |
---|
250 | !!====================================================================== |
---|
251 | END MODULE stpmlf |
---|