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source: palm/trunk/SOURCE/land_surface_model.f90 @ 1513

Last change on this file since 1513 was 1513, checked in by heinze, 9 years ago
bugfix: provide REAL constants with _wp in call of MAX and MIN
Property svn:keywords set to `Id`
File size: 53.7 KB

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1	MODULE land_surface_model_mod
2
3	!--------------------------------------------------------------------------------!
4	! This file is part of PALM.
5	!
6	! PALM is free software: you can redistribute it and/or modify it under the terms
7	! of the GNU General Public License as published by the Free Software Foundation,
8	! either version 3 of the License, or (at your option) any later 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 1997-2014 Leibniz Universitaet Hannover
18	!--------------------------------------------------------------------------------!
19	!
20	! Current revisions:
21	! -----------------
22	! Bugfix: REAL constants provided with KIND-attribute in call of
23	! intrinsic function MAX and MIN
24	!
25	! Former revisions:
26	! -----------------
27	! $Id: land_surface_model.f90 1513 2014-12-19 09:14:10Z heinze $
28	!
29	! 1500 2014-12-03 17:42:41Z maronga
30	! Corrected calculation of aerodynamic resistance (r_a).
31	! Precipitation is now added to liquid water reservoir using LE_liq.
32	! Added support for dry runs.
33	!
34	! 1496 2014-12-02 17:25:50Z maronga
35	! Initial revision
36	!
37	!
38	! Description:
39	! ------------
40	! Land surface model, consisting of a solver for the energy balance at the
41	! surface and a four layer soil scheme. The scheme is similar to the TESSEL
42	! scheme implemented in the ECMWF IFS model, with modifications according to
43	! H-TESSEL. The implementation is based on the formulation implemented in the
44	! DALES model.
45	!
46	! To do list:
47	! -----------
48	! - Add support for binary I/O support
49	! - Add support for lsm data output
50	! - Check for time step criterion
51	! - Check use with RK-2 and Euler time-stepping
52	! - Adaption for use with cloud physics (liquid water potential temperature)
53	! - Check reaction of plants at wilting point and at atmospheric saturation
54	! - Consider partial absorption of the net shortwave radiation by the skin layer
55	! - Allow for water surfaces, check performance for bare soils
56	!------------------------------------------------------------------------------!
57	USE arrays_3d, &
58	ONLY: pt, pt_p, q, q_p, qsws, rif, shf, ts, us, z0, z0h
59
60	USE cloud_parameters, &
61	ONLY: cp, l_d_r, l_v, precipitation_rate, rho_l, r_d, r_v
62
63	USE control_parameters, &
64	ONLY: dt_3d, humidity, intermediate_timestep_count, &
65	intermediate_timestep_count_max, precipitation, pt_surface, &
66	rho_surface, surface_pressure, timestep_scheme, tsc
67
68	USE indices, &
69	ONLY: nxlg, nxrg, nyng, nysg, nzb_s_inner
70
71	USE kinds
72
73	USE radiation_model_mod, &
74	ONLY: Rn, SW_in, sigma_SB
75
76
77	IMPLICIT NONE
78
79	!
80	!-- LSM model constants
81	INTEGER(iwp), PARAMETER :: soil_layers = 4 !: number of soil layers (fixed for now)
82
83	REAL(wp), PARAMETER :: &
84	b_CH = 6.04_wp, & ! Clapp & Hornberger exponent
85	lambda_h_dry = 0.19_wp, & ! heat conductivity for dry soil
86	lambda_h_sm = 3.44_wp, & ! heat conductivity of the soil matrix
87	lambda_h_water = 0.57_wp, & ! heat conductivity of water
88	psi_sat = -0.388_wp, & ! soil matrix potential at saturation
89	rhoC_soil = 2.19E6_wp, & ! volumetric heat capacity of soil
90	rhoC_water = 4.20E6_wp, & ! volumetric heat capacity of water
91	m_max_depth = 0.0002_wp ! Maximum capacity of the water reservoir (m)
92
93
94	!
95	!-- LSM variables
96	INTEGER(iwp) :: veg_type = 2, & !: vegetation type, 0: user-defined, 1-19: generic (see list)
97	soil_type = 3 !: soil type, 0: user-defined, 1-6: generic (see list)
98
99	LOGICAL :: conserve_water_content = .TRUE., & !: open or closed bottom surface for the soil model
100	land_surface = .FALSE. !: flag parameter indicating wheather the lsm is used
101
102	! value 9999999.9_wp -> generic available or user-defined value must be set
103	! otherwise -> no generic variable and user setting is optional
104	REAL(wp) :: alpha_VanGenuchten = 0.0_wp, & !: NAMELIST alpha_VG
105	canopy_resistance_coefficient = 0.0_wp, & !: NAMELIST gD
106	C_skin = 20000.0_wp, & !: Skin heat capacity
107	drho_l_lv, & !: (rho_l * l_v)**-1
108	exn, & !: value of the Exner function
109	e_s = 0.0_wp, & !: saturation water vapour pressure
110	field_capacity = 0.0_wp, & !: NAMELIST m_fc
111	f_shortwave_incoming = 9999999.9_wp, & !: NAMELIST f_SW_in
112	hydraulic_conductivity = 0.0_wp, & !: NAMELIST gamma_w_sat
113	Ke = 0.0_wp, & !: Kersten number
114	lambda_skin_stable = 9999999.9_wp, & !: NAMELIST lambda_skin_s
115	lambda_skin_unstable = 9999999.9_wp, & !: NAMELIST lambda_skin_u
116	leaf_area_index = 9999999.9_wp, & !: NAMELIST LAI
117	l_VanGenuchten = 0.0_WP, & !: NAMELIST l_VG
118	min_canopy_resistance = 110.0_wp, & !: NAMELIST r_s_min
119	m_total = 0.0_wp, & !: weighed total water content of the soil (m3/m3)
120	n_VanGenuchten = 0.0_WP, & !: NAMELIST n_VG
121	q_s = 0.0_wp, & !: saturation specific humidity
122	residual_moisture = 0.0_wp, & !: NAMELIST m_res
123	rho_cp, & !: rho_surface * cp
124	rho_lv, & !: rho * l_v
125	rd_d_rv, & !: r_d / r_v
126	saturation_moisture = 0.0_wp, & !: NAMELIST m_sat
127	vegetation_coverage = 9999999.9_wp, & !: NAMELIST c_veg
128	wilting_point = 0.0_wp !: NAMELIST m_wilt
129
130	REAL(wp), DIMENSION(0:soil_layers-1) :: &
131	ddz_soil, & !: 1/dz_soil
132	ddz_soil_stag, & !: 1/dz_soil_stag
133	dz_soil, & !: soil grid spacing (center-center)
134	dz_soil_stag, & !: soil grid spacing (edge-edge)
135	root_extr = 0.0_wp, & !: root extraction
136	root_fraction = (/0.35_wp, 0.38_wp, 0.23_wp, 0.04_wp/), & !: distribution of root surface area to the individual soil layers
137	soil_level = (/0.07_wp, 0.28_wp, 1.00_wp, 2.89_wp/), & !: soil layer depths (m)
138	soil_moisture = 0.0_wp !: soil moisture content (m3/m3)
139
140	REAL(wp), DIMENSION(0:soil_layers) :: &
141	soil_temperature = 9999999.9_wp !: soil temperature (K)
142
143	#if defined( __nopointer )
144	REAL(wp), DIMENSION(:,:), ALLOCATABLE, TARGET :: T_0, & !: skin temperature (K)
145	T_0_p, & !: progn. skin temperature (K)
146	m_liq, & !: liquid water reservoir (m)
147	m_liq_p !: progn. liquid water reservoir (m)
148	#else
149	REAL(wp), DIMENSION(:,:), POINTER :: T_0, &
150	T_0_p, &
151	m_liq, &
152	m_liq_p
153
154	REAL(wp), DIMENSION(:,:), ALLOCATABLE, TARGET :: T_0_1, T_0_2, &
155	m_liq_1, m_liq_2
156	#endif
157
158	!
159	!-- Temporal tendencies for time stepping
160	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: tT_0_m, & !: skin temperature tendency (K)
161	tm_liq_m !: liquid water reservoir tendency (m)
162
163	!
164	!-- Energy balance variables
165	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: &
166	alpha_VG, & !: coef. of Van Genuchten
167	c_liq, & !: liquid water coverage (of vegetated area)
168	c_veg, & !: vegetation coverage
169	f_SW_in, & !: ?
170	G, & !: surface soil heat flux
171	H, & !: surface flux of sensible heat
172	gamma_w_sat, & !: hydraulic conductivity at saturation
173	gD, & !: coefficient for dependence of r_canopy on water vapour pressure deficit
174	LAI, & !: leaf area index
175	LE, & !: surface flux of latent heat (total)
176	LE_veg, & !: surface flux of latent heat (vegetation portion)
177	LE_soil, & !: surface flux of latent heat (soil portion)
178	LE_liq, & !: surface flux of latent heat (liquid water portion)
179	lambda_h_sat, & !: heat conductivity for dry soil
180	lambda_skin_s, & !: coupling between skin and soil (depends on vegetation type)
181	lambda_skin_u, & !: coupling between skin and soil (depends on vegetation type)
182	l_VG, & !: coef. of Van Genuchten
183	m_fc, & !: soil moisture at field capacity (m3/m3)
184	m_res, & !: residual soil moisture
185	m_sat, & !: saturation soil moisture (m3/m3)
186	m_wilt, & !: soil moisture at permanent wilting point (m3/m3)
187	n_VG, & !: coef. Van Genuchten
188	r_a, & !: aerodynamic resistance
189	r_canopy, & !: canopy resistance
190	r_soil, & !: soil resitance
191	r_soil_min, & !: minimum soil resistance
192	r_s, & !: total surface resistance (combination of r_soil and r_canopy)
193	r_s_min !: minimum canopy resistance
194
195	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: &
196	lambda_h, & !: heat conductivity of soil (?)
197	lambda_w, & !: hydraulic diffusivity of soil (?)
198	gamma_w, & !: hydraulic conductivity of soil (?)
199	rhoC_total !: volumetric heat capacity of the actual soil matrix (?)
200
201	#if defined( __nopointer )
202	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE, TARGET :: &
203	T_soil, & !: Soil temperature (K)
204	T_soil_p, & !: Prog. soil temperature (K)
205	m_soil, & !: Soil moisture (m3/m3)
206	m_soil_p !: Prog. soil moisture (m3/m3)
207	#else
208	REAL(wp), DIMENSION(:,:,:), POINTER :: &
209	T_soil, T_soil_p, &
210	m_soil, m_soil_p
211
212	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE, TARGET :: &
213	T_soil_1, T_soil_2, &
214	m_soil_1, m_soil_2
215
216
217	#endif
218
219
220	REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: &
221	tT_soil_m, & !: T_soil storage array
222	tm_soil_m, & !: m_soil storage array
223	root_fr !: root fraction (sum=1)
224
225	!
226	!-- Land surface parameters according to the following classes (veg_type)
227	!-- (0 user defined)
228	!-- 1 crops, mixed farming
229	!-- 2 short grass
230	!-- 3 evergreen needleleaf trees
231	!-- 4 deciduous needleleaf trees
232	!-- 5 evergreen broadleaf trees
233	!-- 6 deciduous broadleaf trees
234	!-- 7 tall grass
235	!-- 8 desert
236	!-- 9 tundra
237	!-- 10 irrigated crops
238	!-- 11 semidesert
239	!-- 12 ice caps and glaciers
240	!-- 13 bogs and marshes
241	!-- 14 inland water
242	!-- 15 ocean
243	!-- 16 evergreen shrubs
244	!-- 17 deciduous shrubs
245	!-- 18 mixed forest/woodland
246	!-- 19 interrupted forest
247
248	!
249	!-- Land surface parameters I r_s_min, LAI, c_veg, gD
250	REAL(wp), DIMENSION(0:3,1:19) :: veg_pars = RESHAPE( (/ &
251	180.0_wp, 3.00_wp, 0.90_wp, 0.00_wp, & ! 1
252	110.0_wp, 2.00_wp, 0.85_wp, 0.00_wp, & ! 2
253	500.0_wp, 5.00_wp, 0.90_wp, 0.03_wp, & ! 3
254	500.0_wp, 5.00_wp, 0.90_wp, 0.03_wp, & ! 4
255	175.0_wp, 5.00_wp, 0.90_wp, 0.03_wp, & ! 5
256	240.0_wp, 6.00_wp, 0.99_wp, 0.13_wp, & ! 6
257	100.0_wp, 2.00_wp, 0.70_wp, 0.00_wp, & ! 7
258	250.0_wp, 0.50_wp, 0.00_wp, 0.00_wp, & ! 8
259	80.0_wp, 1.00_wp, 0.50_wp, 0.00_wp, & ! 9
260	180.0_wp, 3.00_wp, 0.90_wp, 0.00_wp, & ! 10
261	150.0_wp, 0.50_wp, 0.10_wp, 0.00_wp, & ! 11
262	0.0_wp, 0.00_wp, 0.00_wp, 0.00_wp, & ! 12
263	240.0_wp, 4.00_wp, 0.60_wp, 0.00_wp, & ! 13
264	0.0_wp, 0.00_wp, 0.00_wp, 0.00_wp, & ! 14
265	0.0_wp, 0.00_wp, 0.00_wp, 0.00_wp, & ! 15
266	225.0_wp, 3.00_wp, 0.50_wp, 0.00_wp, & ! 16
267	225.0_wp, 1.50_wp, 0.50_wp, 0.00_wp, & ! 17
268	250.0_wp, 5.00_wp, 0.90_wp, 0.03_wp, & ! 18
269	175.0_wp, 2.50_wp, 0.90_wp, 0.03_wp & ! 19
270	/), (/ 4, 19 /) )
271
272	!
273	!-- Land surface parameters II z0, z0h
274	REAL(wp), DIMENSION(0:1,1:19) :: roughness_par = RESHAPE( (/ &
275	0.25_wp, 0.25E-2_wp, & ! 1
276	0.20_wp, 0.20E-2_wp, & ! 2
277	2.00_wp, 2.00_wp, & ! 3
278	2.00_wp, 2.00_wp, & ! 4
279	2.00_wp, 2.00_wp, & ! 5
280	2.00_wp, 2.00_wp, & ! 6
281	0.47_wp, 0.47E-2_wp, & ! 7
282	0.013_wp, 0.013E-2_wp, & ! 8
283	0.034_wp, 0.034E-2_wp, & ! 9
284	0.5_wp, 0.50E-2_wp, & ! 10
285	0.17_wp, 0.17E-2_wp, & ! 11
286	1.3E-3_wp, 1.3E-4_wp, & ! 12
287	0.83_wp, 0.83E-2_wp, & ! 13
288	0.00_wp, 0.00E-2_wp, & ! 14
289	0.00_wp, 0.00E-2_wp, & ! 15
290	0.10_wp, 0.10E-2_wp, & ! 16
291	0.25_wp, 0.25E-2_wp, & ! 17
292	2.00_wp, 2.00E-2_wp, & ! 18
293	1.10_wp, 1.10E-2_wp & ! 19
294	/), (/ 2, 19 /) )
295
296	!
297	!-- Land surface parameters III lambda_skin_s, lambda_skin_u, f_SW_in
298	REAL(wp), DIMENSION(0:2,1:19) :: skin_pars = RESHAPE( (/ &
299	10.0_wp, 10.0_wp, 0.05_wp, & ! 1
300	10.0_wp, 10.0_wp, 0.05_wp, & ! 2
301	20.0_wp, 15.0_wp, 0.03_wp, & ! 3
302	20.0_wp, 15.0_wp, 0.03_wp, & ! 4
303	20.0_wp, 15.0_wp, 0.03_wp, & ! 5
304	20.0_wp, 15.0_wp, 0.03_wp, & ! 6
305	10.0_wp, 10.0_wp, 0.05_wp, & ! 7
306	15.0_wp, 15.0_wp, 0.00_wp, & ! 8
307	10.0_wp, 10.0_wp, 0.05_wp, & ! 9
308	10.0_wp, 10.0_wp, 0.05_wp, & ! 10
309	10.0_wp, 10.0_wp, 0.05_wp, & ! 11
310	58.0_wp, 58.0_wp, 0.00_wp, & ! 12
311	10.0_wp, 10.0_wp, 0.05_wp, & ! 13
312	1.0E20_wp, 1.0E20_wp, 0.00_wp, & ! 14
313	1.0E20_wp, 1.0E20_wp, 0.00_wp, & ! 15
314	10.0_wp, 10.0_wp, 0.05_wp, & ! 16
315	10.0_wp, 10.0_wp, 0.05_wp, & ! 17
316	20.0_wp, 15.0_wp, 0.03_wp, & ! 18
317	20.0_wp, 15.0_wp, 0.03_wp & ! 19
318	/), (/ 3, 19 /) )
319
320	!
321	!-- Root distribution (sum = 1) level 1, level 2, level 3, level 4,
322	REAL(wp), DIMENSION(0:3,1:19) :: root_distribution = RESHAPE( (/ &
323	0.24_wp, 0.41_wp, 0.31_wp, 0.04_wp, & ! 1
324	0.35_wp, 0.38_wp, 0.23_wp, 0.04_wp, & ! 2
325	0.26_wp, 0.39_wp, 0.29_wp, 0.06_wp, & ! 3
326	0.26_wp, 0.38_wp, 0.29_wp, 0.07_wp, & ! 4
327	0.24_wp, 0.38_wp, 0.31_wp, 0.07_wp, & ! 5
328	0.25_wp, 0.34_wp, 0.27_wp, 0.14_wp, & ! 6
329	0.27_wp, 0.27_wp, 0.27_wp, 0.09_wp, & ! 7
330	1.00_wp, 0.00_wp, 0.00_wp, 0.00_wp, & ! 8
331	0.47_wp, 0.45_wp, 0.08_wp, 0.00_wp, & ! 9
332	0.24_wp, 0.41_wp, 0.31_wp, 0.04_wp, & ! 10
333	0.17_wp, 0.31_wp, 0.33_wp, 0.19_wp, & ! 11
334	0.00_wp, 0.00_wp, 0.00_wp, 0.00_wp, & ! 12
335	0.25_wp, 0.34_wp, 0.27_wp, 0.11_wp, & ! 13
336	0.00_wp, 0.00_wp, 0.00_wp, 0.00_wp, & ! 14
337	0.00_wp, 0.00_wp, 0.00_wp, 0.00_wp, & ! 15
338	0.23_wp, 0.36_wp, 0.30_wp, 0.11_wp, & ! 16
339	0.23_wp, 0.36_wp, 0.30_wp, 0.11_wp, & ! 17
340	0.19_wp, 0.35_wp, 0.36_wp, 0.10_wp, & ! 18
341	0.19_wp, 0.35_wp, 0.36_wp, 0.10_wp & ! 19
342	/), (/ 4, 19 /) )
343
344	!
345	!-- Soil parameters according to the following porosity classes (soil_type)
346	!-- (0 user defined)
347	!-- 1 coarse
348	!-- 2 medium
349	!-- 3 medium-fine
350	!-- 4 fine
351	!-- 5 very fine
352	!-- 6 organic
353	!
354	!-- Soil parameters I alpha_VG, l_VG, n_VG, gamma_w_sat
355	REAL(wp), DIMENSION(0:3,1:6) :: soil_pars = RESHAPE( (/ &
356	3.83_wp, 1.250_wp, 1.38_wp, 6.94E-6_wp, & ! 1
357	3.14_wp, -2.342_wp, 1.28_wp, 1.16E-6_wp, & ! 2
358	0.83_wp, -0.588_wp, 1.25_wp, 0.26E-6_wp, & ! 3
359	3.67_wp, -1.977_wp, 1.10_wp, 2.87E-6_wp, & ! 4
360	2.65_wp, 2.500_wp, 1.10_wp, 1.74E-6_wp, & ! 5
361	1.30_wp, 0.400_wp, 1.20_wp, 0.93E-6_wp & ! 6
362	/), (/ 4, 6 /) )
363
364	!
365	!-- Soil parameters II m_sat, m_fc, m_wilt, m_res
366	REAL(wp), DIMENSION(0:3,1:6) :: m_soil_pars = RESHAPE( (/ &
367	0.403_wp, 0.244_wp, 0.059_wp, 0.025_wp, & ! 1
368	0.439_wp, 0.347_wp, 0.151_wp, 0.010_wp, & ! 2
369	0.430_wp, 0.383_wp, 0.133_wp, 0.010_wp, & ! 3
370	0.520_wp, 0.448_wp, 0.279_wp, 0.010_wp, & ! 4
371	0.614_wp, 0.541_wp, 0.335_wp, 0.010_wp, & ! 5
372	0.766_wp, 0.663_wp, 0.267_wp, 0.010_wp & ! 6
373	/), (/ 4, 6 /) )
374
375
376	SAVE
377
378
379	PRIVATE
380
381
382	PUBLIC alpha_VanGenuchten, C_skin, canopy_resistance_coefficient, &
383	conserve_water_content, field_capacity, f_shortwave_incoming, &
384	hydraulic_conductivity, init_lsm, lambda_skin_stable, &
385	lambda_skin_unstable, land_surface, leaf_area_index, &
386	lsm_energy_balance, lsm_soil_model, l_VanGenuchten, &
387	min_canopy_resistance, n_VanGenuchten, residual_moisture, &
388	root_fraction, saturation_moisture, soil_level, soil_moisture, &
389	soil_temperature, soil_type, vegetation_coverage, veg_type, &
390	wilting_point
391
392	#if defined( __nopointer )
393	PUBLIC m_liq, m_liq_p, m_soil, m_soil_p, T_0, T_0_p, T_soil, T_soil_p
394	#else
395	PUBLIC m_liq, m_liq_1, m_liq_2, m_liq_p, m_soil, m_soil_1, m_soil_2, &
396	m_soil_p, T_0, T_0_1, T_0_2, T_0_p, T_soil, T_soil_1, T_soil_2, &
397	T_soil_p
398	#endif
399
400
401	INTERFACE init_lsm
402	MODULE PROCEDURE init_lsm
403	END INTERFACE init_lsm
404
405	INTERFACE lsm_energy_balance
406	MODULE PROCEDURE lsm_energy_balance
407	END INTERFACE lsm_energy_balance
408
409	INTERFACE lsm_soil_model
410	MODULE PROCEDURE lsm_soil_model
411	END INTERFACE lsm_soil_model
412
413
414	CONTAINS
415
416
417	!------------------------------------------------------------------------------!
418	! Description:
419	! ------------
420	!-- Initialization of the land surface model
421	!------------------------------------------------------------------------------!
422	SUBROUTINE init_lsm
423
424
425	IMPLICIT NONE
426
427	INTEGER(iwp) :: i !: running index
428	INTEGER(iwp) :: j !: running index
429	INTEGER(iwp) :: k !: running index
430
431
432	!
433	!-- Calculate frequently used parameters
434	rho_cp = cp * rho_surface
435	rd_d_rv = r_d / r_v
436	rho_lv = rho_surface * l_v
437	drho_l_lv = 1.0 / (rho_l * l_v)
438
439	!
440	!-- Allocate skin and soil temperature / humidity
441	#if defined( __nopointer )
442	ALLOCATE ( T_0(nysg:nyng,nxlg:nxrg) )
443	ALLOCATE ( T_0_p(nysg:nyng,nxlg:nxrg) )
444	#else
445	ALLOCATE ( T_0_1(nysg:nyng,nxlg:nxrg) )
446	ALLOCATE ( T_0_2(nysg:nyng,nxlg:nxrg) )
447	#endif
448
449	ALLOCATE ( tT_0_m(nysg:nyng,nxlg:nxrg) )
450
451	#if defined( __nopointer )
452	ALLOCATE ( T_soil(0:soil_layers,nysg:nyng,nxlg:nxrg) )
453	ALLOCATE ( T_soil_p(0:soil_layers,nysg:nyng,nxlg:nxrg) )
454	#else
455	ALLOCATE ( T_soil_1(0:soil_layers,nysg:nyng,nxlg:nxrg) )
456	ALLOCATE ( T_soil_2(0:soil_layers,nysg:nyng,nxlg:nxrg) )
457	#endif
458
459	ALLOCATE ( tT_soil_m(0:soil_layers-1,nysg:nyng,nxlg:nxrg) )
460
461	#if defined( __nopointer )
462	ALLOCATE ( m_liq(nysg:nyng,nxlg:nxrg) )
463	ALLOCATE ( m_liq_p(nysg:nyng,nxlg:nxrg) )
464	#else
465	ALLOCATE ( m_liq_1(nysg:nyng,nxlg:nxrg) )
466	ALLOCATE ( m_liq_2(nysg:nyng,nxlg:nxrg) )
467	#endif
468
469	ALLOCATE ( tm_liq_m(nysg:nyng,nxlg:nxrg) )
470
471	#if defined( __nopointer )
472	ALLOCATE ( m_soil(0:soil_layers-1,nysg:nyng,nxlg:nxrg) )
473	ALLOCATE ( m_soil_p(0:soil_layers-1,nysg:nyng,nxlg:nxrg) )
474	#else
475	ALLOCATE ( m_soil_1(0:soil_layers-1,nysg:nyng,nxlg:nxrg) )
476	ALLOCATE ( m_soil_2(0:soil_layers-1,nysg:nyng,nxlg:nxrg) )
477	#endif
478
479	ALLOCATE ( tm_soil_m(0:soil_layers-1,nysg:nyng,nxlg:nxrg) )
480
481
482	#if ! defined( __nopointer )
483	!
484	!-- Initial assignment of the pointers
485	T_soil => T_soil_1; T_soil_p => T_soil_2
486	T_0 => T_0_1; T_0_p => T_0_2
487	m_soil => m_soil_1; m_soil_p => m_soil_2
488	m_liq => m_liq_1; m_liq_p => m_liq_2
489	#endif
490
491	T_0 = 0.0_wp
492	T_0_p = 0.0_wp
493	tT_0_m = 0.0_wp
494
495	T_soil = 0.0_wp
496	T_soil_p = 0.0_wp
497	tT_soil_m = 0.0_wp
498
499	m_liq = 0.0_wp
500	m_liq_p = 0.0_wp
501	tm_liq_m = 0.0_wp
502
503	m_soil = 0.0_wp
504	m_soil_p = 0.0_wp
505	tm_soil_m = 0.0_wp
506
507	!
508	!-- Allocate 2D vegetation model arrays
509	ALLOCATE ( alpha_VG(nysg:nyng,nxlg:nxrg) )
510	ALLOCATE ( c_liq(nysg:nyng,nxlg:nxrg) )
511	ALLOCATE ( c_veg(nysg:nyng,nxlg:nxrg) )
512	ALLOCATE ( f_SW_in(nysg:nyng,nxlg:nxrg) )
513	ALLOCATE ( G(nysg:nyng,nxlg:nxrg) )
514	ALLOCATE ( H(nysg:nyng,nxlg:nxrg) )
515	ALLOCATE ( gamma_w_sat(nysg:nyng,nxlg:nxrg) )
516	ALLOCATE ( gD(nysg:nyng,nxlg:nxrg) )
517	ALLOCATE ( LAI(nysg:nyng,nxlg:nxrg) )
518	ALLOCATE ( LE(nysg:nyng,nxlg:nxrg) )
519	ALLOCATE ( LE_veg(nysg:nyng,nxlg:nxrg) )
520	ALLOCATE ( LE_soil(nysg:nyng,nxlg:nxrg) )
521	ALLOCATE ( LE_liq(nysg:nyng,nxlg:nxrg) )
522	ALLOCATE ( l_VG(nysg:nyng,nxlg:nxrg) )
523	ALLOCATE ( lambda_h_sat(nysg:nyng,nxlg:nxrg) )
524	ALLOCATE ( lambda_skin_u(nysg:nyng,nxlg:nxrg) )
525	ALLOCATE ( lambda_skin_s(nysg:nyng,nxlg:nxrg) )
526	ALLOCATE ( m_fc(nysg:nyng,nxlg:nxrg) )
527	ALLOCATE ( m_res(nysg:nyng,nxlg:nxrg) )
528	ALLOCATE ( m_sat(nysg:nyng,nxlg:nxrg) )
529	ALLOCATE ( m_wilt(nysg:nyng,nxlg:nxrg) )
530	ALLOCATE ( n_VG(nysg:nyng,nxlg:nxrg) )
531	ALLOCATE ( r_a(nysg:nyng,nxlg:nxrg) )
532	ALLOCATE ( r_canopy(nysg:nyng,nxlg:nxrg) )
533	ALLOCATE ( r_soil(nysg:nyng,nxlg:nxrg) )
534	ALLOCATE ( r_soil_min(nysg:nyng,nxlg:nxrg) )
535	ALLOCATE ( r_s(nysg:nyng,nxlg:nxrg) )
536	ALLOCATE ( r_s_min(nysg:nyng,nxlg:nxrg) )
537
538	!
539	!-- Set initial and default values
540	c_liq = 0.0_wp
541	c_veg = 0.0_wp
542	f_SW_in = 0.05_wp
543	gD = 0.0_wp
544	LAI = 0.0_wp
545	lambda_skin_u = 10.0_wp
546	lambda_skin_s = 10.0_wp
547
548
549	G = 0.0_wp
550	H = rho_cp * shf
551
552	IF ( humidity ) THEN
553	LE = rho_l * l_v * qsws
554	ELSE
555	LE = 0.0_wp
556	ENDIF
557
558	LE_veg = 0.0_wp
559	LE_soil = LE
560	LE_liq = 0.0_wp
561
562	r_a = 50.0_wp
563	r_canopy = 0.0_wp
564	r_soil = 0.0_wp
565	r_soil_min = 50.0_wp
566	r_s = 110.0_wp
567	r_s_min = min_canopy_resistance
568
569	!
570	!-- Allocate 3D soil model arrays
571	ALLOCATE ( root_fr(0:soil_layers-1,nysg:nyng,nxlg:nxrg) )
572	ALLOCATE ( lambda_h(0:soil_layers-1,nysg:nyng,nxlg:nxrg) )
573	ALLOCATE ( rhoC_total(0:soil_layers-1,nysg:nyng,nxlg:nxrg) )
574
575	lambda_h = 0.0_wp
576	!
577	!-- If required, allocate humidity-related variables for the soil model
578	IF ( humidity ) THEN
579	ALLOCATE ( lambda_w(0:soil_layers-1,nysg:nyng,nxlg:nxrg) )
580	ALLOCATE ( gamma_w(0:soil_layers-1,nysg:nyng,nxlg:nxrg) )
581
582	lambda_w = 0.0_wp
583	ENDIF
584
585	!
586	!-- Calculate grid spacings. Temperature and moisture are defined at
587	!-- the center of the soil layers, whereas gradients/fluxes are defined
588	!-- at the edges (_stag)
589	dz_soil_stag(0) = soil_level(0)
590
591	DO k = 1, soil_layers-1
592	dz_soil_stag(k) = soil_level(k) - soil_level(k-1)
593	ENDDO
594
595	DO k = 0, soil_layers-2
596	dz_soil(k) = 0.5 * (dz_soil_stag(k+1) + dz_soil_stag(k))
597	ENDDO
598	dz_soil(soil_layers-1) = dz_soil_stag(soil_layers-1)
599
600	ddz_soil = 1.0 / dz_soil
601	ddz_soil_stag = 1.0 / dz_soil_stag
602	!
603	!-- Initialize soil
604	IF ( soil_type .NE. 0 ) THEN
605	alpha_VG = soil_pars(0,soil_type)
606	l_VG = soil_pars(1,soil_type)
607	n_VG = soil_pars(2,soil_type)
608	gamma_w_sat = soil_pars(3,soil_type)
609	m_sat = m_soil_pars(0,soil_type)
610	m_fc = m_soil_pars(1,soil_type)
611	m_wilt = m_soil_pars(2,soil_type)
612	m_res = m_soil_pars(3,soil_type)
613	ELSE
614	alpha_VG = alpha_VanGenuchten
615	l_VG = l_VanGenuchten
616	n_VG = n_VanGenuchten
617	gamma_w_sat = hydraulic_conductivity
618	m_sat = saturation_moisture
619	m_fc = field_capacity
620	m_wilt = wilting_point
621	m_res = residual_moisture
622	ENDIF
623
624	!
625	!-- Map user settings of T and q for each soil layer
626	!-- (make sure that the soil moisture does not drop below the permanent
627	!-- wilting point) -> problems with devision by zero)
628	DO k = 0, soil_layers-1
629	T_soil(k,:,:) = soil_temperature(k)
630	m_soil(k,:,:) = MAX(soil_moisture(k),m_wilt(:,:))
631	ENDDO
632	T_soil(soil_layers,:,:) = soil_temperature(soil_layers)
633
634
635	exn = ( surface_pressure / 1000.0_wp )**0.286_wp
636	T_0 = pt_surface * exn
637
638	T_soil_p = T_soil
639	m_soil_p = m_soil
640
641	!
642	!-- Calculate saturation soil heat conductivity
643	lambda_h_sat(:,:) = lambda_h_sm ** (1.0_wp - m_sat(:,:)) * &
644	lambda_h_water ** m_sat(:,:)
645
646	!
647	!-- Initialize vegetation
648	IF ( veg_type .NE. 0 ) THEN
649
650	r_s_min = veg_pars(0,veg_type)
651	LAI = veg_pars(1,veg_type)
652	c_veg = veg_pars(2,veg_type)
653	gD = veg_pars(3,veg_type)
654	lambda_skin_s = skin_pars(0,veg_type)
655	lambda_skin_u = skin_pars(1,veg_type)
656	f_SW_in = skin_pars(2,veg_type)
657	z0 = roughness_par(0,veg_type)
658	z0h = roughness_par(1,veg_type)
659
660
661	DO k = 0, soil_layers-1
662	root_fr(k,:,:) = root_distribution(k,veg_type)
663	ENDDO
664
665	ELSE
666
667	DO k = 0, soil_layers-1
668	root_fr(k,:,:) = root_fraction(k)
669	ENDDO
670
671	ENDIF
672
673	!
674	!-- Possibly do user-defined actions (e.g. define heterogeneous land surface)
675	CALL user_init_land_surface
676
677	!
678	!-- Set artifical values for ts and us so that r_a has its initial value for
679	!-- the first time step
680	DO i = nxlg, nxrg
681	DO j = nysg, nyng
682	k = nzb_s_inner(j,i)
683	!
684	!-- Assure that r_a cannot be zero at model start
685	IF ( pt(k+1,j,i) == pt(k,j,i) ) pt(k+1,j,i) = pt(k+1,j,i) + 1.0E-10_wp
686
687	us(j,i) = 0.1_wp
688	ts(j,i) = (pt(k+1,j,i) - pt(k,j,i)) / r_a(j,i)
689	shf(j,i) = - us(j,i) * ts(j,i)
690	ENDDO
691	ENDDO
692
693	!
694	!-- Calculate humidity at the surface
695	IF ( humidity ) THEN
696	CALL calc_q0
697	ENDIF
698
699	RETURN
700
701	END SUBROUTINE init_lsm
702
703
704
705	!------------------------------------------------------------------------------!
706	! Description:
707	! ------------
708	!
709	!------------------------------------------------------------------------------!
710	SUBROUTINE lsm_energy_balance
711
712
713	IMPLICIT NONE
714
715	INTEGER(iwp) :: i !: running index
716	INTEGER(iwp) :: j !: running index
717	INTEGER(iwp) :: k, ks !: running index
718
719	REAL(wp) :: f1, & !: resistance correction term 1
720	f2, & !: resistance correction term 2
721	f3, & !: resistance correction term 3
722	m_min, & !: minimum soil moisture
723	T_1, & !: actual temperature at first grid point
724	e, & !: water vapour pressure
725	e_s, & !: water vapour saturation pressure
726	e_s_dT, & !: derivate of e_s with respect to T
727	tend, & !: tendency
728	dq_s_dT, & !: derivate of q_s with respect to T
729	coef_1, & !: coef. for prognostic equation
730	coef_2, & !: coef. for prognostic equation
731	f_LE, & !: factor for LE
732	f_LE_veg, & !: factor for LE_veg
733	f_LE_soil, & !: factor for LE_soil
734	f_LE_liq, & !: factor for LE_liq
735	f_H, & !: factor for H
736	lambda_skin, & !: Current value of lambda_skin
737	m_liq_max !: maxmimum value of the liquid water reservoir
738
739	!
740	!-- Calculate the exner function for the current time step
741	exn = ( surface_pressure / 1000.0_wp )**0.286_wp
742
743
744	DO i = nxlg, nxrg
745	DO j = nysg, nyng
746	k = nzb_s_inner(j,i)
747
748	!
749	!-- Set lambda_skin according to stratification
750	IF ( rif(j,i) >= 0.0_wp ) THEN
751	lambda_skin = lambda_skin_s(j,i)
752	ELSE
753	lambda_skin = lambda_skin_u(j,i)
754	ENDIF
755
756	!
757	!-- First step: calculate aerodyamic resistance. As pt, us, ts
758	!-- are not available for the prognostic time step, data from the last
759	!-- time step is used here. Note that this formulation is the
760	!-- equivalent to the ECMWF formulation using drag coefficients
761	r_a(j,i) = (pt(k+1,j,i) - pt(k,j,i)) / (ts(j,i) * us(j,i) + 1.0E-20)
762
763	!
764	!-- Second step: calculate canopy resistance r_canopy
765	!-- f1-f3 here are defined as 1/f1-f3 as in ECMWF documentation
766
767	!-- f1: correction for incoming shortwave radiation
768	f1 = MIN(1.0_wp, ( 0.004_wp * SW_in(j,i) + 0.05_wp ) / &
769	(0.81_wp * (0.004_wp * SW_in(j,i) + 1.0_wp) ) )
770
771	!
772	!-- f2: correction for soil moisture f2=0 for very dry soil
773	m_total = 0.0_wp
774	DO ks = 0, soil_layers-1
775	m_total = m_total + root_fr(ks,j,i) * m_soil(ks,j,i)
776	ENDDO
777
778	IF ( m_total .GT. m_wilt(j,i) .AND. m_total .LE. m_fc(j,i) ) THEN
779	f2 = ( m_total - m_wilt(j,i) ) / (m_fc(j,i) - m_wilt(j,i) )
780	ELSE
781	f2 = 1.0E-20_wp
782	ENDIF
783
784	!
785	!-- Calculate water vapour pressure at saturation
786	!-- (T_0 should be replaced by liquid water temp?!)
787	e_s = 0.01 * 610.78_wp * EXP( 17.269_wp * ( T_0(j,i) - 273.16_wp )&
788	/ ( T_0(j,i) - 35.86_wp ) )
789
790	!
791	!-- f3: correction for vapour pressure deficit
792	IF ( gD(j,i) .NE. 0.0_wp ) THEN
793	!
794	!-- Calculate vapour pressure
795	e = q_p(k+1,j,i) * surface_pressure / 0.622
796	f3 = EXP ( -gD(j,i) * (e_s - e) )
797	ELSE
798	f3 = 1.0_wp
799	ENDIF
800
801	!
802	!-- To do: check for very dry soil -> r_canopy goes to infinity
803	r_canopy(j,i) = r_s_min(j,i) / (LAI(j,i) * f1 * f2 * f3 + 1.0E-20)
804
805	!
806	!-- Third step: calculate bare soil resistance r_soil
807	m_min = c_veg(j,i) * m_wilt(j,i) + (1.0_wp - c_veg(j,i)) * &
808	m_res(j,i)
809
810	f2 = ( m_soil(0,j,i) - m_min ) / ( m_fc(j,i) - m_min )
811	f2 = MAX(f2,1.0E-20_wp)
812
813	r_soil(j,i) = r_soil_min(j,i) / f2
814
815	!
816	!-- Calculate fraction of liquid water reservoir
817	m_liq_max = m_max_depth * LAI(j,i)
818	c_liq(j,i) = MIN(1.0_wp, m_liq(j,i)/m_liq_max)
819
820	q_s = 0.622_wp * e_s / surface_pressure
821
822	!
823	!-- In case of dew fall, set resistances to zero.
824	!-- To do: what does that physically reasoning behind this?
825	IF ( humidity ) THEN
826	IF ( q_s .LE. q_p(k+1,j,i) ) THEN
827	r_canopy(j,i) = 0.0_wp
828	r_soil(j,i) = 0.0_wp
829	ENDIF
830	ENDIF
831
832
833	!
834	!-- Calculate coefficients for the total evapotranspiration
835	f_LE_veg = rho_lv * c_veg(j,i) * (1.0 - c_liq(j,i)) / (r_a(j,i) &
836	+ r_canopy(j,i))
837	f_LE_soil = rho_lv * (1.0 - c_veg(j,i)) / (r_a(j,i) + r_soil(j,i))
838	f_LE_liq = rho_lv * c_veg(j,i) * c_liq(j,i) / r_a(j,i)
839
840
841	!
842	!-- If soil moisture is below wilting point, plants do no longer
843	!-- transpirate.
844	IF ( m_soil(k,j,i) .LT. m_wilt(j,i) ) THEN
845	f_LE_veg = 0.0
846	ENDIF
847
848	f_H = rho_cp / r_a(j,i)
849	f_LE = f_LE_veg + f_LE_soil + f_LE_liq
850
851	!
852	!-- Calculate derivative of q_s for Taylor series expansion
853	e_s_dT = e_s * ( 17.269_wp / (T_0(j,i) - 35.86_wp) - &
854	17.269_wp*(T_0(j,i) - 273.16_wp) / (T_0(j,i) &
855	- 35.86_wp)**2 )
856
857	dq_s_dT = 0.622_wp * e_s_dT / surface_pressure
858
859	T_1 = pt_p(k+1,j,i) * exn
860
861	!
862	!-- Add LW up so that it can be removed in prognostic equation
863	Rn(j,i) = Rn(j,i) + sigma_SB * T_0(j,i) ** 4
864
865	IF ( humidity ) THEN
866
867	!
868	!-- Numerator of the prognostic equation
869	coef_1 = Rn(j,i) + 3.0_wp * sigma_SB * T_0(j,i) ** 4 + f_H &
870	/ exn * T_1 + f_LE * ( q_p(k+1,j,i) - q_s + dq_s_dT &
871	* T_0(j,i) ) + lambda_skin * T_soil(0,j,i)
872
873	!
874	!-- Denominator of the prognostic equation
875	coef_2 = 4.0_wp * sigma_SB * T_0(j,i) ** 3 + f_LE * dq_s_dT &
876	+ lambda_skin + f_H / exn
877
878	ELSE
879
880	!
881	!-- Numerator of the prognostic equation
882	coef_1 = Rn(j,i) + 3.0_wp * sigma_SB * T_0(j,i) ** 4 + f_H / &
883	exn * T_1 + lambda_skin * T_soil(0,j,i)
884
885	!
886	!-- Denominator of the prognostic equation
887	coef_2 = 4.0_wp * sigma_SB * T_0(j,i) ** 3 &
888	+ lambda_skin + f_H / exn
889
890	ENDIF
891
892	tend = 0.0_wp
893
894	!
895	!-- Implicit solution when the skin layer has no heat capacity,
896	!-- otherwise use RK3 scheme.
897	T_0_p(j,i) = ( coef_1 * dt_3d * tsc(2) + C_skin * T_0(j,i) ) / &
898	( C_skin + coef_2 * dt_3d * tsc(2) )
899
900	!
901	!-- Add RK3 term
902	T_0_p(j,i) = T_0_p(j,i) + dt_3d * tsc(3) * tT_soil_m(0,j,i)
903
904	!
905	!-- Calculate true tendency
906	tend = (T_0_p(j,i) - T_0(j,i) - tsc(3) * tT_0_m(j,i)) / (dt_3d &
907	* tsc(2))
908
909	!
910	!-- Calculate T_0 tendencies for the next Runge-Kutta step
911	IF ( timestep_scheme(1:5) == 'runge' ) THEN
912	IF ( intermediate_timestep_count == 1 ) THEN
913	tT_0_m(j,i) = tend
914	ELSEIF ( intermediate_timestep_count < &
915	intermediate_timestep_count_max ) THEN
916	tT_0_m(j,i) = -9.5625_wp * tend + 5.3125_wp * tT_0_m(j,i)
917	ENDIF
918	ENDIF
919
920	pt_p(k,j,i) = T_0_p(j,i) / exn
921	!
922	!-- Calculate fluxes
923	Rn(j,i) = Rn(j,i) + 3.0_wp * sigma_SB * T_0(j,i)**4 &
924	- 4.0_wp * sigma_SB * T_0(j,i)*3 T_0_p(j,i)
925	G(j,i) = lambda_skin * (T_0_p(j,i) - T_soil(0,j,i))
926	H(j,i) = - f_H * ( pt_p(k+1,j,i) - pt_p(k,j,i) )
927
928	IF ( humidity ) THEN
929	LE(j,i) = - f_LE * ( q_p(k+1,j,i) - q_s + dq_s_dT &
930	* T_0(j,i) - dq_s_dT * T_0_p(j,i) )
931
932	LE_veg(j,i) = - f_LE_veg * ( q_p(k+1,j,i) - q_s + dq_s_dT &
933	* T_0(j,i) - dq_s_dT * T_0_p(j,i) )
934	LE_soil(j,i) = - f_LE_soil * ( q_p(k+1,j,i) - q_s + dq_s_dT &
935	* T_0(j,i) - dq_s_dT * T_0_p(j,i) )
936	LE_liq(j,i) = - f_LE_liq * ( q_p(k+1,j,i) - q_s + dq_s_dT &
937	* T_0(j,i) - dq_s_dT * T_0_p(j,i) )
938	ENDIF
939
940	! IF ( i == 1 .AND. j == 1 ) THEN
941	! PRINT*, "Rn", Rn(j,i)
942	! PRINT*, "H", H(j,i)
943	! PRINT*, "LE", LE(j,i)
944	! PRINT*, "LE_liq", LE_liq(j,i)
945	! PRINT*, "LE_veg", LE_veg(j,i)
946	! PRINT*, "LE_soil", LE_soil(j,i)
947	! PRINT*, "G", G(j,i)
948	! ENDIF
949
950	!
951	!-- Calculate the true surface resistance
952	IF ( LE(j,i) .EQ. 0.0 ) THEN
953	r_s(j,i) = 1.0E10
954	ELSE
955	r_s(j,i) = - rho_lv * ( q_p(k+1,j,i) - q_s + dq_s_dT * T_0(j,i)&
956	- dq_s_dT * T_0_p(j,i) ) / LE(j,i) - r_a(j,i)
957	ENDIF
958
959	!
960	!-- Calculate fluxes in the atmosphere
961	shf(j,i) = H(j,i) / rho_cp
962
963	!
964	!-- Calculate change in liquid water reservoir due to dew fall or
965	!-- evaporation of liquid water
966	IF ( humidity ) THEN
967	!
968	!-- If precipitation is activated, add rain water to LE_liq.
969	!-- precipitation_rate is given in mm.
970	IF ( precipitation ) THEN
971	LE_liq(j,i) = LE_liq(j,i) + precipitation_rate(j,i) &
972	* 0.001_wp * rho_l * l_v
973	ENDIF
974	!
975	!-- If the air is saturated, check the reservoir water level
976	IF ( q_s .LE. q_p(k+1,j,i)) THEN
977	!
978	!-- Check if reservoir is full (avoid values > m_liq_max)
979	!-- In that case, LE_liq goes to LE_soil. In this case
980	!-- LE_veg is zero anyway (because c_liq = 1), so that tend is
981	!-- zero and no further check is needed
982	IF ( m_liq(j,i) .EQ. m_liq_max ) THEN
983	LE_soil(j,i) = LE_soil(j,i) + LE_liq(j,i)
984	LE_liq(j,i) = 0.0_wp
985	ENDIF
986
987	!
988	!-- In case LE_veg becomes negative (unphysical behavior), let
989	!-- the water enter the liquid water reservoir as dew on the
990	!-- plant
991	IF ( LE_veg(j,i) .LT. 0.0_wp ) THEN
992	LE_liq(j,i) = LE_liq(j,i) + LE_veg(j,i)
993	LE_veg(j,i) = 0.0_wp
994	ENDIF
995	ENDIF
996
997	tend = - LE_liq(j,i) * drho_l_lv
998
999	m_liq_p(j,i) = m_liq(j,i) + dt_3d * ( tsc(2) * tend &
1000	+ tsc(3) * tm_liq_m(j,i) )
1001
1002	!
1003	!-- Check if reservoir is overfull -> reduce to maximum
1004	!-- (conservation of water is violated here)
1005	m_liq_p(j,i) = MIN(m_liq_p(j,i),m_liq_max)
1006
1007	!
1008	!-- Check if reservoir is empty (avoid values < 0.0)
1009	!-- (conservation of water is violated here)
1010	m_liq_p(j,i) = MAX(m_liq_p(j,i),0.0_wp)
1011
1012
1013	!
1014	!-- Calculate m_liq tendencies for the next Runge-Kutta step
1015	IF ( timestep_scheme(1:5) == 'runge' ) THEN
1016	IF ( intermediate_timestep_count == 1 ) THEN
1017	tm_liq_m(j,i) = tend
1018	ELSEIF ( intermediate_timestep_count < &
1019	intermediate_timestep_count_max ) THEN
1020	tm_liq_m(j,i) = -9.5625_wp * tend + 5.3125_wp &
1021	* tm_liq_m(j,i)
1022	ENDIF
1023	ENDIF
1024
1025	!
1026	!-- Calculate moisture flux in the atmosphere
1027	qsws(j,i) = LE(j,i) / rho_lv
1028
1029	ENDIF
1030
1031	ENDDO
1032	ENDDO
1033
1034
1035
1036	END SUBROUTINE lsm_energy_balance
1037
1038
1039	!------------------------------------------------------------------------------!
1040	! Description:
1041	! ------------
1042	!
1043	!------------------------------------------------------------------------------!
1044	SUBROUTINE lsm_soil_model
1045
1046
1047	IMPLICIT NONE
1048
1049	INTEGER(iwp) :: i !: running index
1050	INTEGER(iwp) :: j !: running index
1051	INTEGER(iwp) :: k !: running index
1052
1053	REAL(wp) :: h_VG !: Van Genuchten coef. h
1054
1055	REAL(wp), DIMENSION(0:soil_layers-1) :: gamma_temp, & !: temp. gamma
1056	lambda_temp, & !: temp. lambda
1057	tend !: tendency
1058
1059	DO i = nxlg, nxrg
1060	DO j = nysg, nyng
1061	DO k = 0, soil_layers-1
1062	!
1063	!-- Calculate volumetric heat capacity of the soil, taking into
1064	!-- account water content
1065	rhoC_total(k,j,i) = (rhoC_soil * (1.0 - m_sat(j,i)) &
1066	+ rhoC_water * m_soil(k,j,i))
1067
1068	!
1069	!-- Calculate soil heat conductivity at the center of the soil
1070	!-- layers
1071	Ke = 1.0 + LOG10(MAX(0.1_wp,m_soil(k,j,i) / m_sat(j,i)))
1072	lambda_temp(k) = Ke * (lambda_h_sat(j,i) + lambda_h_dry) + &
1073	lambda_h_dry
1074
1075	ENDDO
1076
1077	!
1078	!-- Calculate soil heat conductivity (lambda_h) at the _stag level
1079	!-- using linear interpolation
1080	DO k = 0, soil_layers-2
1081
1082	lambda_h(k,j,i) = lambda_temp(k) + &
1083	( lambda_temp(k+1) - lambda_temp(k) ) &
1084	* 0.5 * dz_soil_stag(k) * ddz_soil(k+1)
1085
1086	ENDDO
1087	lambda_h(soil_layers-1,j,i) = lambda_temp(soil_layers-1)
1088
1089	!
1090	!-- Prognostic equation for soil temperature T_soil
1091	tend(:) = 0.0_wp
1092	tend(0) = (1.0/rhoC_total(0,j,i)) * &
1093	( lambda_h(0,j,i) * ( T_soil(1,j,i) - T_soil(0,j,i) ) &
1094	* ddz_soil(0) + G(j,i) ) * ddz_soil_stag(0)
1095
1096	DO k = 1, soil_layers-1
1097	tend(k) = (1.0/rhoC_total(k,j,i)) &
1098	* ( lambda_h(k,j,i) &
1099	* ( T_soil(k+1,j,i) - T_soil(k,j,i) ) &
1100	* ddz_soil(k) &
1101	- lambda_h(k-1,j,i) &
1102	* ( T_soil(k,j,i) - T_soil(k-1,j,i) ) &
1103	* ddz_soil(k-1) &
1104	) * ddz_soil_stag(k)
1105	ENDDO
1106
1107	T_soil_p(0:soil_layers-1,j,i) = T_soil(0:soil_layers-1,j,i) &
1108	+ dt_3d * ( tsc(2) &
1109	* tend(:) + tsc(3) &
1110	* tT_soil_m(:,j,i) )
1111
1112	!
1113	!-- Calculate T_soil tendencies for the next Runge-Kutta step
1114	IF ( timestep_scheme(1:5) == 'runge' ) THEN
1115	IF ( intermediate_timestep_count == 1 ) THEN
1116	DO k = 0, soil_layers-1
1117	tT_soil_m(k,j,i) = tend(k)
1118	ENDDO
1119	ELSEIF ( intermediate_timestep_count < &
1120	intermediate_timestep_count_max ) THEN
1121	DO k = 0, soil_layers-1
1122	tT_soil_m(k,j,i) = -9.5625_wp * tend(k) + 5.3125_wp &
1123	* tT_soil_m(k,j,i)
1124	ENDDO
1125	ENDIF
1126	ENDIF
1127
1128
1129	DO k = 0, soil_layers-1
1130	!
1131	!-- Calculate soil diffusivity at the center of the soil layers
1132	lambda_temp(k) = (- b_CH * gamma_w_sat(j,i) * psi_sat &
1133	/ m_sat(j,i) ) * ( MAX(m_soil(k,j,i), &
1134	m_wilt(j,i)) / m_sat(j,i) )**(b_CH + 2.0_wp)
1135
1136	!
1137	!-- Calculate the hydraulic conductivity after Van Genuchten (1980)
1138	h_VG = ( ( (m_res(j,i) - m_sat(j,i)) / ( m_res(j,i) - &
1139	MAX(m_soil(k,j,i),m_wilt(j,i)) ) )**(n_VG(j,i) &
1140	/ (n_VG(j,i)-1.0_wp)) - 1.0_wp &
1141	)**(1.0_wp/n_VG(j,i)) / alpha_VG(j,i)
1142
1143	gamma_temp(k) = gamma_w_sat(j,i) * ( ( (1.0_wp + &
1144	(alpha_VG(j,i)h_VG)n_VG(j,i))*(1.0_wp &
1145	-1.0_wp/n_VG(j,i)) - (alpha_VG(j,i)*h_VG &
1146	)(n_VG(j,i)-1.0_wp))2 ) &
1147	/ ( (1.0_wp + (alpha_VG(j,i)h_VG)*n_VG(j,i) &
1148	)*((1.0_wp - 1.0_wp/n_VG(j,i))(l_VG(j,i) &
1149	+ 2.0)) )
1150
1151	ENDDO
1152
1153
1154	IF ( humidity ) THEN
1155	!
1156	!-- Calculate soil diffusivity (lambda_w) at the _stag level
1157	!-- using linear interpolation
1158	DO k = 0, soil_layers-2
1159
1160	lambda_w(k,j,i) = lambda_temp(k) + &
1161	( lambda_temp(k+1) - lambda_temp(k) ) &
1162	* 0.5 * dz_soil_stag(k) * ddz_soil(k+1)
1163	gamma_w(k,j,i) = gamma_temp(k) + &
1164	( gamma_temp(k+1) - gamma_temp(k) ) &
1165	* 0.5 * dz_soil_stag(k) * ddz_soil(k+1)
1166
1167	ENDDO
1168
1169	!
1170	!
1171	!-- In case of a closed bottom (= water content is conserved), set
1172	!-- hydraulic conductivity to zero to that no water will be lost
1173	!-- in the bottom layer.
1174	IF ( conserve_water_content ) THEN
1175	gamma_w(soil_layers-1,j,i) = 0.0_wp
1176	ELSE
1177	gamma_w(soil_layers-1,j,i) = lambda_temp(soil_layers-1)
1178	ENDIF
1179
1180	!-- The root extraction (= root_extr * LE_veg / (rho_l * l_v))
1181	!-- ensures the mass conservation for water. The transpiration of
1182	!-- plants equals the cumulative withdrawals by the roots in the
1183	!-- soil. The scheme takes into account the availability of water
1184	!-- in the soil layers as well as the root fraction in the
1185	!-- respective layer
1186
1187	!
1188	!-- Calculate the root extraction (ECMWF 7.69, with some
1189	!-- modifications)
1190	m_total = 0.0_wp
1191	DO k = 0, soil_layers-1
1192	m_total = m_total + root_fr(k,j,i) * m_soil(k,j,i) * &
1193	dz_soil_stag(k)
1194
1195	ENDDO
1196
1197	!
1198	!-- For conservation of mass, the sum of root_extr must be 1
1199	DO k = 0, soil_layers-1
1200	root_extr(k) = root_fr(k,j,i) * m_soil(k,j,i) &
1201	* dz_soil_stag(k) / m_total
1202	ENDDO
1203
1204
1205	!
1206	!-- Prognostic equation for soil water content m_soil
1207	tend(:) = 0.0_wp
1208	tend(0) = ( lambda_w(0,j,i) * ( m_soil(1,j,i) - m_soil(0,j,i) )&
1209	* ddz_soil(0) - gamma_w(0,j,i) - ( root_extr(0) &
1210	* LE_veg(j,i) + LE_soil(j,i) ) * drho_l_lv &
1211	) * ddz_soil_stag(0)
1212
1213	DO k = 1, soil_layers-2
1214	tend(k) = ( lambda_w(k,j,i) * ( m_soil(k+1,j,i) &
1215	- m_soil(k,j,i) ) * ddz_soil(k) - gamma_w(k,j,i)&
1216	- lambda_w(k-1,j,i) * (m_soil(k,j,i) - &
1217	m_soil(k-1,j,i)) * ddz_soil(k-1) &
1218	+ gamma_w(k-1,j,i) - (root_extr(k) * LE_veg(j,i)&
1219	* drho_l_lv) &
1220	) * ddz_soil_stag(k)
1221
1222	ENDDO
1223	tend(soil_layers-1) = ( - gamma_w(soil_layers-1,j,i) &
1224	- lambda_w(soil_layers-2,j,i) &
1225	* (m_soil(soil_layers-1,j,i) &
1226	- m_soil(soil_layers-2,j,i)) &
1227	* ddz_soil(soil_layers-2) &
1228	+ gamma_w(soil_layers-2,j,i) - ( &
1229	root_extr(soil_layers-1) &
1230	* LE_veg(j,i) * drho_l_lv ) &
1231	) * ddz_soil_stag(soil_layers-1)
1232
1233	m_soil_p(0:soil_layers-1,j,i) = m_soil(0:soil_layers-1,j,i) &
1234	+ dt_3d * ( tsc(2) * tend(:) &
1235	+ tsc(3) * tm_soil_m(:,j,i) )
1236
1237	!
1238	!-- Account for dry soils (find a better solution here!)
1239	m_soil_p(:,j,i) = MAX(m_soil_p(:,j,i),0.0_wp)
1240
1241	!
1242	!-- Calculate m_soil tendencies for the next Runge-Kutta step
1243	IF ( timestep_scheme(1:5) == 'runge' ) THEN
1244	IF ( intermediate_timestep_count == 1 ) THEN
1245	DO k = 0, soil_layers-1
1246	tm_soil_m(k,j,i) = tend(k)
1247	ENDDO
1248	ELSEIF ( intermediate_timestep_count < &
1249	intermediate_timestep_count_max ) THEN
1250	DO k = 0, soil_layers-1
1251	tm_soil_m(k,j,i) = -9.5625_wp * tend(k) + 5.3125_wp &
1252	* tm_soil_m(k,j,i)
1253	ENDDO
1254	ENDIF
1255	ENDIF
1256
1257	ENDIF
1258
1259	ENDDO
1260	ENDDO
1261
1262	!
1263	!-- Calculate surface specific humidity
1264	IF ( humidity ) THEN
1265	CALL calc_q0
1266	ENDIF
1267
1268
1269	END SUBROUTINE lsm_soil_model
1270
1271
1272	!------------------------------------------------------------------------------!
1273	! Description:
1274	! ------------
1275	!
1276	!------------------------------------------------------------------------------!
1277	SUBROUTINE calc_q0
1278
1279	IMPLICIT NONE
1280
1281	INTEGER :: i !: running index
1282	INTEGER :: j !: running index
1283	INTEGER :: k !: running index
1284	REAL(wp) :: resistance !: aerodynamic and soil resistance term
1285
1286	DO i = nxlg, nxrg
1287	DO j = nysg, nyng
1288	k = nzb_s_inner(j,i)
1289	!
1290	!-- Temporary solution as long as T_0 is prescribed
1291
1292	pt_p(k,j,i) = T_0(j,i) / exn
1293	!
1294	!-- Calculate water vapour pressure at saturation
1295	e_s = 0.01_wp * 610.78_wp * EXP( 17.269_wp * ( T_0(j,i) - &
1296	273.16_wp ) / ( T_0(j,i) - &
1297	35.86_wp ) )
1298
1299	!
1300	!-- Calculate specific humidity at saturation
1301	q_s = 0.622_wp * e_s / surface_pressure
1302
1303
1304	resistance = r_a(j,i) / (r_a(j,i) + r_s(j,i))
1305
1306	!
1307	!-- Calculate specific humidity at surface
1308	q_p(k,j,i) = resistance * q_s + (1.0_wp - resistance) &
1309	* q_p(k+1,j,i)
1310
1311	ENDDO
1312	ENDDO
1313
1314	END SUBROUTINE calc_q0
1315
1316
1317	END MODULE land_surface_model_mod

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