Home

Context Navigation

source: palm/trunk/SOURCE/plant_canopy_model.f90 @ 1682

Last change on this file since 1682 was 1682, checked in by knoop, 9 years ago
Code annotations made doxygen readable
Property svn:keywords set to `Id`
File size: 40.7 KB

Line
1	!> @file plant_canopy_model.f90
2	!--------------------------------------------------------------------------------!
3	! This file is part of PALM.
4	!
5	! PALM is free software: you can redistribute it and/or modify it under the terms
6	! of the GNU General Public License as published by the Free Software Foundation,
7	! either version 3 of the License, or (at your option) any later version.
8	!
9	! PALM is distributed in the hope that it will be useful, but WITHOUT ANY
10	! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
11	! A PARTICULAR PURPOSE. See the GNU General Public License for more details.
12	!
13	! You should have received a copy of the GNU General Public License along with
14	! PALM. If not, see <http://www.gnu.org/licenses/>.
15	!
16	! Copyright 1997-2014 Leibniz Universitaet Hannover
17	!--------------------------------------------------------------------------------!
18	!
19	! Current revisions:
20	! -----------------
21	! Code annotations made doxygen readable
22	!
23	! Former revisions:
24	! -----------------
25	! $Id: plant_canopy_model.f90 1682 2015-10-07 23:56:08Z knoop $
26	!
27	! 1484 2014-10-21 10:53:05Z kanani
28	! Changes due to new module structure of the plant canopy model:
29	! module plant_canopy_model_mod now contains a subroutine for the
30	! initialization of the canopy model (init_plant_canopy),
31	! limitation of the canopy drag (previously accounted for by calculation of
32	! a limiting canopy timestep for the determination of the maximum LES timestep
33	! in subroutine timestep) is now realized by the calculation of pre-tendencies
34	! and preliminary velocities in subroutine plant_canopy_model,
35	! some redundant MPI communication removed in subroutine init_plant_canopy
36	! (was previously in init_3d_model),
37	! unnecessary 3d-arrays lad_u, lad_v, lad_w removed - lad information on the
38	! respective grid is now provided only by lad_s (e.g. in the calculation of
39	! the tendency terms or of cum_lai_hf),
40	! drag_coefficient, lai, leaf_surface_concentration,
41	! scalar_exchange_coefficient, sec and sls renamed to canopy_drag_coeff,
42	! cum_lai_hf, leaf_surface_conc, leaf_scalar_exch_coeff, lsec and lsc,
43	! respectively,
44	! unnecessary 3d-arrays cdc, lsc and lsec now defined as single-value constants,
45	! USE-statements and ONLY-lists modified accordingly
46	!
47	! 1340 2014-03-25 19:45:13Z kanani
48	! REAL constants defined as wp-kind
49	!
50	! 1320 2014-03-20 08:40:49Z raasch
51	! ONLY-attribute added to USE-statements,
52	! kind-parameters added to all INTEGER and REAL declaration statements,
53	! kinds are defined in new module kinds,
54	! old module precision_kind is removed,
55	! revision history before 2012 removed,
56	! comment fields (!:) to be used for variable explanations added to
57	! all variable declaration statements
58	!
59	! 1036 2012-10-22 13:43:42Z raasch
60	! code put under GPL (PALM 3.9)
61	!
62	! 138 2007-11-28 10:03:58Z letzel
63	! Initial revision
64	!
65	! Description:
66	! ------------
67	!> 1) Initialization of the canopy model, e.g. construction of leaf area density
68	!> profile (subroutine init_plant_canopy).
69	!> 2) Calculation of sinks and sources of momentum, heat and scalar concentration
70	!> due to canopy elements (subroutine plant_canopy_model).
71	!------------------------------------------------------------------------------!
72	MODULE plant_canopy_model_mod
73
74	USE arrays_3d, &
75	ONLY: dzu, dzw, e, q, shf, tend, u, v, w, zu, zw
76
77	USE indices, &
78	ONLY: nbgp, nxl, nxlg, nxlu, nxr, nxrg, nyn, nyng, nys, nysg, nysv, &
79	nz, nzb, nzb_s_inner, nzb_u_inner, nzb_v_inner, nzb_w_inner, nzt
80
81	USE kinds
82
83
84	IMPLICIT NONE
85
86
87	CHARACTER (LEN=20) :: canopy_mode = 'block' !< canopy coverage
88
89	INTEGER(iwp) :: pch_index = 0 !< plant canopy height/top index
90	INTEGER(iwp) :: &
91	lad_vertical_gradient_level_ind(10) = -9999 !< lad-profile levels (index)
92
93	LOGICAL :: calc_beta_lad_profile = .FALSE. !< switch for calc. of lad from beta func.
94	LOGICAL :: plant_canopy = .FALSE. !< switch for use of canopy model
95
96	REAL(wp) :: alpha_lad = 9999999.9_wp !< coefficient for lad calculation
97	REAL(wp) :: beta_lad = 9999999.9_wp !< coefficient for lad calculation
98	REAL(wp) :: canopy_drag_coeff = 0.0_wp !< canopy drag coefficient (parameter)
99	REAL(wp) :: cdc = 0.0_wp !< canopy drag coeff. (abbreviation used in equations)
100	REAL(wp) :: cthf = 0.0_wp !< canopy top heat flux
101	REAL(wp) :: dt_plant_canopy = 0.0_wp !< timestep account. for canopy drag
102	REAL(wp) :: lad_surface = 0.0_wp !< lad surface value
103	REAL(wp) :: lai_beta = 0.0_wp !< leaf area index (lai) for lad calc.
104	REAL(wp) :: &
105	leaf_scalar_exch_coeff = 0.0_wp !< canopy scalar exchange coeff.
106	REAL(wp) :: &
107	leaf_surface_conc = 0.0_wp !< leaf surface concentration
108	REAL(wp) :: lsec = 0.0_wp !< leaf scalar exchange coeff.
109	REAL(wp) :: lsc = 0.0_wp !< leaf surface concentration
110
111	REAL(wp) :: &
112	lad_vertical_gradient(10) = 0.0_wp !< lad gradient
113	REAL(wp) :: &
114	lad_vertical_gradient_level(10) = -9999999.9_wp !< lad-prof. levels (in m)
115
116	REAL(wp), DIMENSION(:), ALLOCATABLE :: lad !< leaf area density
117	REAL(wp), DIMENSION(:), ALLOCATABLE :: pre_lad !< preliminary lad
118
119	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: &
120	canopy_heat_flux !< canopy heat flux
121	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: cum_lai_hf !< cumulative lai for heatflux calc.
122	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: lad_s !< lad on scalar-grid
123
124
125	SAVE
126
127
128	PRIVATE
129	PUBLIC alpha_lad, beta_lad, calc_beta_lad_profile, canopy_drag_coeff, &
130	canopy_mode, cdc, cthf, dt_plant_canopy, init_plant_canopy, lad, &
131	lad_s, lad_surface, lad_vertical_gradient, &
132	lad_vertical_gradient_level, lad_vertical_gradient_level_ind, &
133	lai_beta, leaf_scalar_exch_coeff, leaf_surface_conc, lsc, lsec, &
134	pch_index, plant_canopy, plant_canopy_model
135
136
137	INTERFACE init_plant_canopy
138	MODULE PROCEDURE init_plant_canopy
139	END INTERFACE init_plant_canopy
140
141	INTERFACE plant_canopy_model
142	MODULE PROCEDURE plant_canopy_model
143	MODULE PROCEDURE plant_canopy_model_ij
144	END INTERFACE plant_canopy_model
145
146
147
148
149	CONTAINS
150
151
152	!------------------------------------------------------------------------------!
153	! Description:
154	! ------------
155	!> Initialization of the plant canopy model
156	!------------------------------------------------------------------------------!
157	SUBROUTINE init_plant_canopy
158
159
160	USE control_parameters, &
161	ONLY: dz, ocean, passive_scalar
162
163
164	IMPLICIT NONE
165
166	INTEGER(iwp) :: i !< running index
167	INTEGER(iwp) :: j !< running index
168	INTEGER(iwp) :: k !< running index
169
170	REAL(wp) :: int_bpdf !< vertical integral for lad-profile construction
171	REAL(wp) :: dzh !< vertical grid spacing in units of canopy height
172	REAL(wp) :: gradient !< gradient for lad-profile construction
173	REAL(wp) :: canopy_height !< canopy height for lad-profile construction
174
175	!
176	!-- Allocate one-dimensional arrays for the computation of the
177	!-- leaf area density (lad) profile
178	ALLOCATE( lad(0:nz+1), pre_lad(0:nz+1) )
179	lad = 0.0_wp
180	pre_lad = 0.0_wp
181
182	!
183	!-- Compute the profile of leaf area density used in the plant
184	!-- canopy model. The profile can either be constructed from
185	!-- prescribed vertical gradients of the leaf area density or by
186	!-- using a beta probability density function (see e.g. Markkanen et al.,
187	!-- 2003: Boundary-Layer Meteorology, 106, 437-459)
188	IF ( .NOT. calc_beta_lad_profile ) THEN
189
190	!
191	!-- Use vertical gradients for lad-profile construction
192	i = 1
193	gradient = 0.0_wp
194
195	IF ( .NOT. ocean ) THEN
196
197	lad(0) = lad_surface
198	lad_vertical_gradient_level_ind(1) = 0
199
200	DO k = 1, pch_index
201	IF ( i < 11 ) THEN
202	IF ( lad_vertical_gradient_level(i) < zu(k) .AND. &
203	lad_vertical_gradient_level(i) >= 0.0_wp ) THEN
204	gradient = lad_vertical_gradient(i)
205	lad_vertical_gradient_level_ind(i) = k - 1
206	i = i + 1
207	ENDIF
208	ENDIF
209	IF ( gradient /= 0.0_wp ) THEN
210	IF ( k /= 1 ) THEN
211	lad(k) = lad(k-1) + dzu(k) * gradient
212	ELSE
213	lad(k) = lad_surface + dzu(k) * gradient
214	ENDIF
215	ELSE
216	lad(k) = lad(k-1)
217	ENDIF
218	ENDDO
219
220	ENDIF
221
222	!
223	!-- In case of no given leaf area density gradients, choose a vanishing
224	!-- gradient. This information is used for the HEADER and the RUN_CONTROL
225	!-- file.
226	IF ( lad_vertical_gradient_level(1) == -9999999.9_wp ) THEN
227	lad_vertical_gradient_level(1) = 0.0_wp
228	ENDIF
229
230	ELSE
231
232	!
233	!-- Use beta function for lad-profile construction
234	int_bpdf = 0.0_wp
235	canopy_height = pch_index * dz
236
237	DO k = nzb, pch_index
238	int_bpdf = int_bpdf + &
239	( ( ( zw(k) / canopy_height )*( alpha_lad-1.0_wp ) ) &
240	( ( 1.0_wp - ( zw(k) / canopy_height ) )*( beta_lad-1.0_wp ) ) &
241	( ( zw(k+1)-zw(k) ) / canopy_height ) )
242	ENDDO
243
244	!
245	!-- Preliminary lad profile (defined on w-grid)
246	DO k = nzb, pch_index
247	pre_lad(k) = lai_beta * &
248	( ( ( zw(k) / canopy_height )*( alpha_lad-1.0_wp ) ) &
249	( ( 1.0_wp - ( zw(k) / canopy_height ) )**( beta_lad-1.0_wp ) ) / &
250	int_bpdf &
251	) / canopy_height
252	ENDDO
253
254	!
255	!-- Final lad profile (defined on scalar-grid level, since most prognostic
256	!-- quantities are defined there, hence, less interpolation is required
257	!-- when calculating the canopy tendencies)
258	lad(0) = pre_lad(0)
259	DO k = nzb+1, pch_index
260	lad(k) = 0.5 * ( pre_lad(k-1) + pre_lad(k) )
261	ENDDO
262
263	ENDIF
264
265	!
266	!-- Allocate 3D-array for the leaf area density (lad_s). In case of a
267	!-- prescribed canopy-top heat flux (cthf), allocate 3D-arrays for
268	!-- the cumulative leaf area index (cum_lai_hf) and the canopy heat flux.
269	ALLOCATE( lad_s(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
270
271	IF ( cthf /= 0.0_wp ) THEN
272	ALLOCATE( cum_lai_hf(nzb:nzt+1,nysg:nyng,nxlg:nxrg), &
273	canopy_heat_flux(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
274	ENDIF
275
276	!
277	!-- Initialize canopy parameters cdc (canopy drag coefficient),
278	!-- lsec (leaf scalar exchange coefficient), lsc (leaf surface concentration)
279	!-- with the prescribed values
280	cdc = canopy_drag_coeff
281	lsec = leaf_scalar_exch_coeff
282	lsc = leaf_surface_conc
283
284	!
285	!-- Initialization of the canopy coverage in the model domain:
286	!-- Setting the parameter canopy_mode = 'block' initializes a canopy, which
287	!-- fully covers the domain surface
288	SELECT CASE ( TRIM( canopy_mode ) )
289
290	CASE( 'block' )
291
292	DO i = nxlg, nxrg
293	DO j = nysg, nyng
294	lad_s(:,j,i) = lad(:)
295	ENDDO
296	ENDDO
297
298	CASE DEFAULT
299
300	!
301	!-- The DEFAULT case is reached either if the parameter
302	!-- canopy mode contains a wrong character string or if the
303	!-- user has coded a special case in the user interface.
304	!-- There, the subroutine user_init_plant_canopy checks
305	!-- which of these two conditions applies.
306	CALL user_init_plant_canopy
307
308	END SELECT
309
310	!
311	!-- Initialization of the canopy heat source distribution
312	IF ( cthf /= 0.0_wp ) THEN
313	!
314	!-- Piecewise calculation of the leaf area index by vertical
315	!-- integration of the leaf area density
316	cum_lai_hf(:,:,:) = 0.0_wp
317	DO i = nxlg, nxrg
318	DO j = nysg, nyng
319	DO k = pch_index-1, 0, -1
320	IF ( k == pch_index-1 ) THEN
321	cum_lai_hf(k,j,i) = cum_lai_hf(k+1,j,i) + &
322	( 0.5_wp * lad_s(k+1,j,i) * &
323	( zw(k+1) - zu(k+1) ) ) + &
324	( 0.5_wp * ( 0.5_wp * ( lad_s(k+1,j,i) + &
325	lad_s(k,j,i) ) + &
326	lad_s(k+1,j,i) ) * &
327	( zu(k+1) - zw(k) ) )
328	ELSE
329	cum_lai_hf(k,j,i) = cum_lai_hf(k+1,j,i) + &
330	( 0.5_wp * ( 0.5_wp * ( lad_s(k+2,j,i) + &
331	lad_s(k+1,j,i) ) + &
332	lad_s(k+1,j,i) ) * &
333	( zw(k+1) - zu(k+1) ) ) + &
334	( 0.5_wp * ( 0.5_wp * ( lad_s(k+1,j,i) + &
335	lad_s(k,j,i) ) + &
336	lad_s(k+1,j,i) ) * &
337	( zu(k+1) - zw(k) ) )
338	ENDIF
339	ENDDO
340	ENDDO
341	ENDDO
342
343	!
344	!-- Calculation of the upward kinematic vertical heat flux within the
345	!-- canopy
346	DO i = nxlg, nxrg
347	DO j = nysg, nyng
348	DO k = 0, pch_index
349	canopy_heat_flux(k,j,i) = cthf * &
350	exp( -0.6_wp * cum_lai_hf(k,j,i) )
351	ENDDO
352	ENDDO
353	ENDDO
354
355	!
356	!-- The surface heat flux is set to the surface value of the calculated
357	!-- in-canopy heat flux distribution
358	shf(:,:) = canopy_heat_flux(0,:,:)
359
360	ENDIF
361
362
363
364	END SUBROUTINE init_plant_canopy
365
366
367
368	!------------------------------------------------------------------------------!
369	! Description:
370	! ------------
371	!> Calculation of the tendency terms, accounting for the effect of the plant
372	!> canopy on momentum and scalar quantities.
373	!>
374	!> The canopy is located where the leaf area density lad_s(k,j,i) > 0.0
375	!> (defined on scalar grid), as initialized in subroutine init_plant_canopy.
376	!> The lad on the w-grid is vertically interpolated from the surrounding
377	!> lad_s. The upper boundary of the canopy is defined on the w-grid at
378	!> k = pch_index. Here, the lad is zero.
379	!>
380	!> The canopy drag must be limited (previously accounted for by calculation of
381	!> a limiting canopy timestep for the determination of the maximum LES timestep
382	!> in subroutine timestep), since it is physically impossible that the canopy
383	!> drag alone can locally change the sign of a velocity component. This
384	!> limitation is realized by calculating preliminary tendencies and velocities.
385	!> It is subsequently checked if the preliminary new velocity has a different
386	!> sign than the current velocity. If so, the tendency is limited in a way that
387	!> the velocity can at maximum be reduced to zero by the canopy drag.
388	!>
389	!>
390	!> Call for all grid points
391	!------------------------------------------------------------------------------!
392	SUBROUTINE plant_canopy_model( component )
393
394
395	USE control_parameters, &
396	ONLY: dt_3d, message_string
397
398	USE kinds
399
400	IMPLICIT NONE
401
402	INTEGER(iwp) :: component !< prognostic variable (u,v,w,pt,q,e)
403	INTEGER(iwp) :: i !< running index
404	INTEGER(iwp) :: j !< running index
405	INTEGER(iwp) :: k !< running index
406
407	REAL(wp) :: ddt_3d !< inverse of the LES timestep (dt_3d)
408	REAL(wp) :: lad_local !< local lad value
409	REAL(wp) :: pre_tend !< preliminary tendency
410	REAL(wp) :: pre_u !< preliminary u-value
411	REAL(wp) :: pre_v !< preliminary v-value
412	REAL(wp) :: pre_w !< preliminary w-value
413
414
415	ddt_3d = 1.0_wp / dt_3d
416
417	!
418	!-- Compute drag for the three velocity components and the SGS-TKE:
419	SELECT CASE ( component )
420
421	!
422	!-- u-component
423	CASE ( 1 )
424	DO i = nxlu, nxr
425	DO j = nys, nyn
426	DO k = nzb_u_inner(j,i)+1, pch_index
427
428	!
429	!-- In order to create sharp boundaries of the plant canopy,
430	!-- the lad on the u-grid at index (k,j,i) is equal to
431	!-- lad_s(k,j,i), rather than being interpolated from the
432	!-- surrounding lad_s, because this would yield smaller lad
433	!-- at the canopy boundaries than inside of the canopy.
434	!-- For the same reason, the lad at the rightmost(i+1)canopy
435	!-- boundary on the u-grid equals lad_s(k,j,i).
436	lad_local = lad_s(k,j,i)
437	IF ( lad_local == 0.0_wp .AND. &
438	lad_s(k,j,i-1) > 0.0_wp ) THEN
439	lad_local = lad_s(k,j,i-1)
440	ENDIF
441
442	pre_tend = 0.0_wp
443	pre_u = 0.0_wp
444	!
445	!-- Calculate preliminary value (pre_tend) of the tendency
446	pre_tend = - cdc * &
447	lad_local * &
448	SQRT( u(k,j,i)**2 + &
449	( 0.25_wp * ( v(k,j,i-1) + &
450	v(k,j,i) + &
451	v(k,j+1,i) + &
452	v(k,j+1,i-1) ) &
453	)**2 + &
454	( 0.25_wp * ( w(k-1,j,i-1) + &
455	w(k-1,j,i) + &
456	w(k,j,i-1) + &
457	w(k,j,i) ) &
458	)**2 &
459	) * &
460	u(k,j,i)
461
462	!
463	!-- Calculate preliminary new velocity, based on pre_tend
464	pre_u = u(k,j,i) + dt_3d * pre_tend
465	!
466	!-- Compare sign of old velocity and new preliminary velocity,
467	!-- and in case the signs are different, limit the tendency
468	IF ( SIGN(pre_u,u(k,j,i)) /= pre_u ) THEN
469	pre_tend = - u(k,j,i) * ddt_3d
470	ELSE
471	pre_tend = pre_tend
472	ENDIF
473	!
474	!-- Calculate final tendency
475	tend(k,j,i) = tend(k,j,i) + pre_tend
476
477	ENDDO
478	ENDDO
479	ENDDO
480
481	!
482	!-- v-component
483	CASE ( 2 )
484	DO i = nxl, nxr
485	DO j = nysv, nyn
486	DO k = nzb_v_inner(j,i)+1, pch_index
487
488	!
489	!-- In order to create sharp boundaries of the plant canopy,
490	!-- the lad on the v-grid at index (k,j,i) is equal to
491	!-- lad_s(k,j,i), rather than being interpolated from the
492	!-- surrounding lad_s, because this would yield smaller lad
493	!-- at the canopy boundaries than inside of the canopy.
494	!-- For the same reason, the lad at the northmost(j+1) canopy
495	!-- boundary on the v-grid equals lad_s(k,j,i).
496	lad_local = lad_s(k,j,i)
497	IF ( lad_local == 0.0_wp .AND. &
498	lad_s(k,j-1,i) > 0.0_wp ) THEN
499	lad_local = lad_s(k,j-1,i)
500	ENDIF
501
502	pre_tend = 0.0_wp
503	pre_v = 0.0_wp
504	!
505	!-- Calculate preliminary value (pre_tend) of the tendency
506	pre_tend = - cdc * &
507	lad_local * &
508	SQRT( ( 0.25_wp * ( u(k,j-1,i) + &
509	u(k,j-1,i+1) + &
510	u(k,j,i) + &
511	u(k,j,i+1) ) &
512	)**2 + &
513	v(k,j,i)**2 + &
514	( 0.25_wp * ( w(k-1,j-1,i) + &
515	w(k-1,j,i) + &
516	w(k,j-1,i) + &
517	w(k,j,i) ) &
518	)**2 &
519	) * &
520	v(k,j,i)
521
522	!
523	!-- Calculate preliminary new velocity, based on pre_tend
524	pre_v = v(k,j,i) + dt_3d * pre_tend
525	!
526	!-- Compare sign of old velocity and new preliminary velocity,
527	!-- and in case the signs are different, limit the tendency
528	IF ( SIGN(pre_v,v(k,j,i)) /= pre_v ) THEN
529	pre_tend = - v(k,j,i) * ddt_3d
530	ELSE
531	pre_tend = pre_tend
532	ENDIF
533	!
534	!-- Calculate final tendency
535	tend(k,j,i) = tend(k,j,i) + pre_tend
536
537	ENDDO
538	ENDDO
539	ENDDO
540
541	!
542	!-- w-component
543	CASE ( 3 )
544	DO i = nxl, nxr
545	DO j = nys, nyn
546	DO k = nzb_w_inner(j,i)+1, pch_index-1
547
548	pre_tend = 0.0_wp
549	pre_w = 0.0_wp
550	!
551	!-- Calculate preliminary value (pre_tend) of the tendency
552	pre_tend = - cdc * &
553	(0.5_wp * &
554	( lad_s(k+1,j,i) + lad_s(k,j,i) )) * &
555	SQRT( ( 0.25_wp * ( u(k,j,i) + &
556	u(k,j,i+1) + &
557	u(k+1,j,i) + &
558	u(k+1,j,i+1) ) &
559	)**2 + &
560	( 0.25_wp * ( v(k,j,i) + &
561	v(k,j+1,i) + &
562	v(k+1,j,i) + &
563	v(k+1,j+1,i) ) &
564	)**2 + &
565	w(k,j,i)**2 &
566	) * &
567	w(k,j,i)
568	!
569	!-- Calculate preliminary new velocity, based on pre_tend
570	pre_w = w(k,j,i) + dt_3d * pre_tend
571	!
572	!-- Compare sign of old velocity and new preliminary velocity,
573	!-- and in case the signs are different, limit the tendency
574	IF ( SIGN(pre_w,w(k,j,i)) /= pre_w ) THEN
575	pre_tend = - w(k,j,i) * ddt_3d
576	ELSE
577	pre_tend = pre_tend
578	ENDIF
579	!
580	!-- Calculate final tendency
581	tend(k,j,i) = tend(k,j,i) + pre_tend
582
583	ENDDO
584	ENDDO
585	ENDDO
586
587	!
588	!-- potential temperature
589	CASE ( 4 )
590	DO i = nxl, nxr
591	DO j = nys, nyn
592	DO k = nzb_s_inner(j,i)+1, pch_index
593	tend(k,j,i) = tend(k,j,i) + &
594	( canopy_heat_flux(k,j,i) - &
595	canopy_heat_flux(k-1,j,i) ) / dzw(k)
596	ENDDO
597	ENDDO
598	ENDDO
599
600	!
601	!-- scalar concentration
602	CASE ( 5 )
603	DO i = nxl, nxr
604	DO j = nys, nyn
605	DO k = nzb_s_inner(j,i)+1, pch_index
606	tend(k,j,i) = tend(k,j,i) - &
607	lsec * &
608	lad_s(k,j,i) * &
609	SQRT( ( 0.5_wp * ( u(k,j,i) + &
610	u(k,j,i+1) ) &
611	)**2 + &
612	( 0.5_wp * ( v(k,j,i) + &
613	v(k,j+1,i) ) &
614	)**2 + &
615	( 0.5_wp * ( w(k-1,j,i) + &
616	w(k,j,i) ) &
617	)**2 &
618	) * &
619	( q(k,j,i) - lsc )
620	ENDDO
621	ENDDO
622	ENDDO
623
624	!
625	!-- sgs-tke
626	CASE ( 6 )
627	DO i = nxl, nxr
628	DO j = nys, nyn
629	DO k = nzb_s_inner(j,i)+1, pch_index
630	tend(k,j,i) = tend(k,j,i) - &
631	2.0_wp * cdc * &
632	lad_s(k,j,i) * &
633	SQRT( ( 0.5_wp * ( u(k,j,i) + &
634	u(k,j,i+1) ) &
635	)**2 + &
636	( 0.5_wp * ( v(k,j,i) + &
637	v(k,j+1,i) ) &
638	)**2 + &
639	( 0.5_wp * ( w(k,j,i) + &
640	w(k+1,j,i) ) &
641	)**2 &
642	) * &
643	e(k,j,i)
644	ENDDO
645	ENDDO
646	ENDDO
647
648
649	CASE DEFAULT
650
651	WRITE( message_string, * ) 'wrong component: ', component
652	CALL message( 'plant_canopy_model', 'PA0279', 1, 2, 0, 6, 0 )
653
654	END SELECT
655
656	END SUBROUTINE plant_canopy_model
657
658
659	!------------------------------------------------------------------------------!
660	! Description:
661	! ------------
662	!> Calculation of the tendency terms, accounting for the effect of the plant
663	!> canopy on momentum and scalar quantities.
664	!>
665	!> The canopy is located where the leaf area density lad_s(k,j,i) > 0.0
666	!> (defined on scalar grid), as initialized in subroutine init_plant_canopy.
667	!> The lad on the w-grid is vertically interpolated from the surrounding
668	!> lad_s. The upper boundary of the canopy is defined on the w-grid at
669	!> k = pch_index. Here, the lad is zero.
670	!>
671	!> The canopy drag must be limited (previously accounted for by calculation of
672	!> a limiting canopy timestep for the determination of the maximum LES timestep
673	!> in subroutine timestep), since it is physically impossible that the canopy
674	!> drag alone can locally change the sign of a velocity component. This
675	!> limitation is realized by calculating preliminary tendencies and velocities.
676	!> It is subsequently checked if the preliminary new velocity has a different
677	!> sign than the current velocity. If so, the tendency is limited in a way that
678	!> the velocity can at maximum be reduced to zero by the canopy drag.
679	!>
680	!>
681	!> Call for grid point i,j
682	!------------------------------------------------------------------------------!
683	SUBROUTINE plant_canopy_model_ij( i, j, component )
684
685
686	USE control_parameters, &
687	ONLY: dt_3d, message_string
688
689	USE kinds
690
691	IMPLICIT NONE
692
693	INTEGER(iwp) :: component !< prognostic variable (u,v,w,pt,q,e)
694	INTEGER(iwp) :: i !< running index
695	INTEGER(iwp) :: j !< running index
696	INTEGER(iwp) :: k !< running index
697
698	REAL(wp) :: ddt_3d !< inverse of the LES timestep (dt_3d)
699	REAL(wp) :: lad_local !< local lad value
700	REAL(wp) :: pre_tend !< preliminary tendency
701	REAL(wp) :: pre_u !< preliminary u-value
702	REAL(wp) :: pre_v !< preliminary v-value
703	REAL(wp) :: pre_w !< preliminary w-value
704
705
706	ddt_3d = 1.0_wp / dt_3d
707
708	!
709	!-- Compute drag for the three velocity components and the SGS-TKE
710	SELECT CASE ( component )
711
712	!
713	!-- u-component
714	CASE ( 1 )
715	DO k = nzb_u_inner(j,i)+1, pch_index
716
717	!
718	!-- In order to create sharp boundaries of the plant canopy,
719	!-- the lad on the u-grid at index (k,j,i) is equal to lad_s(k,j,i),
720	!-- rather than being interpolated from the surrounding lad_s,
721	!-- because this would yield smaller lad at the canopy boundaries
722	!-- than inside of the canopy.
723	!-- For the same reason, the lad at the rightmost(i+1)canopy
724	!-- boundary on the u-grid equals lad_s(k,j,i).
725	lad_local = lad_s(k,j,i)
726	IF ( lad_local == 0.0_wp .AND. &
727	lad_s(k,j,i-1) > 0.0_wp ) THEN
728	lad_local = lad_s(k,j,i-1)
729	ENDIF
730
731	pre_tend = 0.0_wp
732	pre_u = 0.0_wp
733	!
734	!-- Calculate preliminary value (pre_tend) of the tendency
735	pre_tend = - cdc * &
736	lad_local * &
737	SQRT( u(k,j,i)**2 + &
738	( 0.25_wp * ( v(k,j,i-1) + &
739	v(k,j,i) + &
740	v(k,j+1,i) + &
741	v(k,j+1,i-1) ) &
742	)**2 + &
743	( 0.25_wp * ( w(k-1,j,i-1) + &
744	w(k-1,j,i) + &
745	w(k,j,i-1) + &
746	w(k,j,i) ) &
747	)**2 &
748	) * &
749	u(k,j,i)
750
751	!
752	!-- Calculate preliminary new velocity, based on pre_tend
753	pre_u = u(k,j,i) + dt_3d * pre_tend
754	!
755	!-- Compare sign of old velocity and new preliminary velocity,
756	!-- and in case the signs are different, limit the tendency
757	IF ( SIGN(pre_u,u(k,j,i)) /= pre_u ) THEN
758	pre_tend = - u(k,j,i) * ddt_3d
759	ELSE
760	pre_tend = pre_tend
761	ENDIF
762	!
763	!-- Calculate final tendency
764	tend(k,j,i) = tend(k,j,i) + pre_tend
765	ENDDO
766
767
768	!
769	!-- v-component
770	CASE ( 2 )
771	DO k = nzb_v_inner(j,i)+1, pch_index
772
773	!
774	!-- In order to create sharp boundaries of the plant canopy,
775	!-- the lad on the v-grid at index (k,j,i) is equal to lad_s(k,j,i),
776	!-- rather than being interpolated from the surrounding lad_s,
777	!-- because this would yield smaller lad at the canopy boundaries
778	!-- than inside of the canopy.
779	!-- For the same reason, the lad at the northmost(j+1)canopy
780	!-- boundary on the v-grid equals lad_s(k,j,i).
781	lad_local = lad_s(k,j,i)
782	IF ( lad_local == 0.0_wp .AND. &
783	lad_s(k,j-1,i) > 0.0_wp ) THEN
784	lad_local = lad_s(k,j-1,i)
785	ENDIF
786
787	pre_tend = 0.0_wp
788	pre_v = 0.0_wp
789	!
790	!-- Calculate preliminary value (pre_tend) of the tendency
791	pre_tend = - cdc * &
792	lad_local * &
793	SQRT( ( 0.25_wp * ( u(k,j-1,i) + &
794	u(k,j-1,i+1) + &
795	u(k,j,i) + &
796	u(k,j,i+1) ) &
797	)**2 + &
798	v(k,j,i)**2 + &
799	( 0.25_wp * ( w(k-1,j-1,i) + &
800	w(k-1,j,i) + &
801	w(k,j-1,i) + &
802	w(k,j,i) ) &
803	)**2 &
804	) * &
805	v(k,j,i)
806
807	!
808	!-- Calculate preliminary new velocity, based on pre_tend
809	pre_v = v(k,j,i) + dt_3d * pre_tend
810	!
811	!-- Compare sign of old velocity and new preliminary velocity,
812	!-- and in case the signs are different, limit the tendency
813	IF ( SIGN(pre_v,v(k,j,i)) /= pre_v ) THEN
814	pre_tend = - v(k,j,i) * ddt_3d
815	ELSE
816	pre_tend = pre_tend
817	ENDIF
818	!
819	!-- Calculate final tendency
820	tend(k,j,i) = tend(k,j,i) + pre_tend
821	ENDDO
822
823
824	!
825	!-- w-component
826	CASE ( 3 )
827	DO k = nzb_w_inner(j,i)+1, pch_index-1
828
829	pre_tend = 0.0_wp
830	pre_w = 0.0_wp
831	!
832	!-- Calculate preliminary value (pre_tend) of the tendency
833	pre_tend = - cdc * &
834	(0.5_wp * &
835	( lad_s(k+1,j,i) + lad_s(k,j,i) )) * &
836	SQRT( ( 0.25_wp * ( u(k,j,i) + &
837	u(k,j,i+1) + &
838	u(k+1,j,i) + &
839	u(k+1,j,i+1) ) &
840	)**2 + &
841	( 0.25_wp * ( v(k,j,i) + &
842	v(k,j+1,i) + &
843	v(k+1,j,i) + &
844	v(k+1,j+1,i) ) &
845	)**2 + &
846	w(k,j,i)**2 &
847	) * &
848	w(k,j,i)
849	!
850	!-- Calculate preliminary new velocity, based on pre_tend
851	pre_w = w(k,j,i) + dt_3d * pre_tend
852	!
853	!-- Compare sign of old velocity and new preliminary velocity,
854	!-- and in case the signs are different, limit the tendency
855	IF ( SIGN(pre_w,w(k,j,i)) /= pre_w ) THEN
856	pre_tend = - w(k,j,i) * ddt_3d
857	ELSE
858	pre_tend = pre_tend
859	ENDIF
860	!
861	!-- Calculate final tendency
862	tend(k,j,i) = tend(k,j,i) + pre_tend
863	ENDDO
864
865	!
866	!-- potential temperature
867	CASE ( 4 )
868	DO k = nzb_s_inner(j,i)+1, pch_index
869	tend(k,j,i) = tend(k,j,i) + &
870	( canopy_heat_flux(k,j,i) - &
871	canopy_heat_flux(k-1,j,i) ) / dzw(k)
872	ENDDO
873
874
875	!
876	!-- scalar concentration
877	CASE ( 5 )
878	DO k = nzb_s_inner(j,i)+1, pch_index
879	tend(k,j,i) = tend(k,j,i) - &
880	lsec * &
881	lad_s(k,j,i) * &
882	SQRT( ( 0.5_wp * ( u(k,j,i) + &
883	u(k,j,i+1) ) &
884	)**2 + &
885	( 0.5_wp * ( v(k,j,i) + &
886	v(k,j+1,i) ) &
887	)**2 + &
888	( 0.5_wp * ( w(k-1,j,i) + &
889	w(k,j,i) ) &
890	)**2 &
891	) * &
892	( q(k,j,i) - lsc )
893	ENDDO
894
895	!
896	!-- sgs-tke
897	CASE ( 6 )
898	DO k = nzb_s_inner(j,i)+1, pch_index
899	tend(k,j,i) = tend(k,j,i) - &
900	2.0_wp * cdc * &
901	lad_s(k,j,i) * &
902	SQRT( ( 0.5_wp * ( u(k,j,i) + &
903	u(k,j,i+1) ) &
904	)**2 + &
905	( 0.5_wp * ( v(k,j,i) + &
906	v(k,j+1,i) ) &
907	)**2 + &
908	( 0.5_wp * ( w(k,j,i) + &
909	w(k+1,j,i) ) &
910	)**2 &
911	) * &
912	e(k,j,i)
913	ENDDO
914
915	CASE DEFAULT
916
917	WRITE( message_string, * ) 'wrong component: ', component
918	CALL message( 'plant_canopy_model', 'PA0279', 1, 2, 0, 6, 0 )
919
920	END SELECT
921
922	END SUBROUTINE plant_canopy_model_ij
923
924	END MODULE plant_canopy_model_mod

Note: See TracBrowser for help on using the repository browser.

Download in other formats:

| Impressum | ©Leibniz Universität Hannover |