Context Navigation

source: branches/publications/ORCHIDEE_gmd-2018-261/src_stomate/stomate_vmax.f90 @ 8692

Last change on this file since 8692 was 2853, checked in by nicolas.vuichard, 9 years ago
merge with the trunk of the files of the stomate component done
Property svn:keywords set to `HeadURL Date Author Revision`
File size: 12.5 KB

Line
1	! =================================================================================================================================
2	! MODULE : stomate_vmax
3	!
4	! CONTACT : orchidee-help _at_ ipsl.jussieu.fr
5	!
6	! LICENCE : IPSL (2006). This software is governed by the CeCILL licence see ORCHIDEE/ORCHIDEE_CeCILL.LIC
7	!
8	!>\BRIEF calculates the leaf efficiency.
9	!!
10	!!\n DESCRIPTION: None
11	!!
12	!! RECENT CHANGE(S): None
13	!!
14	!! SVN :
15	!! $HeadURL$
16	!! $Date$
17	!! $Revision$
18	!! \n
19	!_ =================================================================================================================================
20
21	MODULE stomate_vmax
22
23	! modules used:
24
25	USE ioipsl_para
26	USE stomate_data
27	USE constantes
28	USE pft_parameters
29
30	IMPLICIT NONE
31
32	! private & public routines
33
34	PRIVATE
35	PUBLIC vmax, vmax_clear
36
37	! first call
38	LOGICAL, SAVE :: firstcall_vmax = .TRUE.
39	!$OMP THREADPRIVATE(firstcall_vmax)
40
41	CONTAINS
42
43	!! ================================================================================================================================
44	!! SUBROUTINE : vmax_clear
45	!!
46	!>\BRIEF Flag setting
47	!!
48	!!\n DESCRIPTION: This subroutine sets flags ::firstcall_vmax, to .TRUE., and therefore activates
49	!! section 1.1 of the ::vmax subroutine which writes messages to the output. \n
50	!! This subroutine is called at the end of the subroutine ::stomate_clear, in the
51	!! module ::stomate.
52	!!
53	!! RECENT CHANGE(S):None
54	!!
55	!! MAIN OUTPUT VARIABLE(S): ::firstcall_vmax
56	!!
57	!! REFERENCE(S) : None
58	!!
59	!! FLOWCHART : None
60	!! \n
61	!_ =================================================================================================================================
62
63	SUBROUTINE vmax_clear
64	firstcall_vmax=.TRUE.
65	END SUBROUTINE vmax_clear
66
67
68
69	!! ================================================================================================================================
70	!! SUBROUTINE : vmax
71	!!
72	!>\BRIEF This subroutine computes vcmax photosynthesis parameters
73	!! given optimal vcmax parameter values and a leaf age-related efficiency.
74	!!
75	!! DESCRIPTION (functional, design, flags):
76	!! Leaf age classes are introduced to take into account the fact that photosynthetic activity depends on leaf age
77	!! (Ishida et al., 1999). There are \f$nleafages\f$ classes (constant defined in stomate_constants.f90).
78	!! This subroutine first calculates the new age of each leaf age-class based on fraction of leaf
79	!! that goes from one to another class.
80	!! Then calculation of the new fraction of leaf in each class is performed.
81	!! Last, leaf efficiency is calculated for each PFT and for each leaf age class.
82	!! vcmax is defined as vcmax25 and vjmax_opt weighted by a mean leaf
83	!! efficiency. vcmax25 is PFT-dependent constants defined in constants_mtc.f90.
84	!!
85	!! This routine is called once at the beginning by stomate_var_init and then at each stomate time step by stomateLpj.
86	!!
87	!! RECENT CHANGE(S): None
88	!!
89	!! MAIN OUTPUT VARIABLE(S): vcmax
90	!!
91	!! REFERENCE(S) :
92	!! - Ishida, A., A. Uemura, N. Koike, Y. Matsumoto, and A. Lai Hoe (1999),
93	!! Interactive effects of leaf age and self-shading on leaf structure, photosynthetic
94	!! capacity and chlorophyll fluorescence in the rain forest tree,
95	!! dryobalanops aromatica, Tree Physiol., 19, 741-747
96	!!
97	!! FLOWCHART : None
98	!!
99	!! REVISION(S) : None
100	!! \n
101	!_ ================================================================================================================================
102
103	SUBROUTINE vmax (npts, dt, &
104	leaf_age, leaf_frac, &
105	vcmax, nue)
106
107	!
108	!! 0. Variable and parameter declaration
109	!
110
111	!
112	!! 0.1 Input variables
113	!
114	INTEGER(i_std), INTENT(in) :: npts !! Domain size (unitless)
115	REAL(r_std), INTENT(in) :: dt !! time step of stomate (days)
116
117	!
118	!! 0.2 Output variables
119	!
120	REAL(r_std), DIMENSION(npts,nvm), INTENT(out) :: vcmax !! Maximum rate of carboxylation
121	!! @tex ($\mu mol m^{-2} s^{-1}$) @endtex
122	REAL(r_std),DIMENSION (npts,nvm), INTENT(out) :: nue !! Nitrogen use Efficiency with impact of leaf age (umol CO2 (gN)-1 s-1)
123	!
124	!! 0.3 Modified variables
125	!
126	REAL(r_std), DIMENSION(npts,nvm,nleafages), INTENT(inout) :: leaf_age !! Leaf age (days)
127	REAL(r_std), DIMENSION(npts,nvm,nleafages), INTENT(inout) :: leaf_frac !! fraction of leaves in leaf age
128	!! classes
129	!! (unitless)
130
131	!
132	!! 0.4 Local variables
133	!
134	REAL(r_std), DIMENSION(npts) :: leaf_efficiency !! leaf efficiency (vcmax/vcmax25)
135	!! (unitless)
136	REAL(r_std), DIMENSION(npts,nvm,nleafages) :: d_leaf_frac !! turnover between age classes
137	!! (unitless)
138	REAL(r_std), DIMENSION(npts,nleafages) :: leaf_age_new !! new leaf age (days)
139	REAL(r_std), DIMENSION(npts) :: sumfrac !! sum of leaf age fractions,
140	!! for normalization
141	!! (unitless)
142	REAL(r_std), DIMENSION(npts) :: rel_age !! relative leaf age (age/critical age)
143	!! (unitless)
144	INTEGER(i_std) :: j,m !! indices (unitless)
145
146	!_ ================================================================================================================================
147
148	IF (printlev>=3) WRITE(numout,*) 'Entering vmax'
149
150	!
151	!! 1 Initialization
152	!
153
154	!
155	!! 1.1 first call: info about flags and parameters.
156	!
157
158	IF ( firstcall_vmax ) THEN
159
160	WRITE(numout,*) 'vmax:'
161
162	WRITE(numout,*) ' > offset (minimum vcmax/vmax_opt):' , vmax_offset
163	WRITE(numout,*) ' > relative leaf age at which vmax reaches vcmax_opt:', leafage_firstmax
164	WRITE(numout,*) ' > relative leaf age at which vmax falls below vcmax_opt:', leafage_lastmax
165	WRITE(numout,*) ' > relative leaf age at which vmax reaches its minimum:', leafage_old
166
167	firstcall_vmax = .FALSE.
168
169	ENDIF
170
171	!
172	!! 1.2 initialize output
173	!
174
175	vcmax(:,:) = zero
176	nue(:,:) = zero
177	!
178	!! 2 leaf age: general increase and turnover between age classes.
179	!
180
181	!
182	!! 2.1 increase leaf age
183	!
184	!
185	!! The age of the leaves in each leaf-age-class increases by 1 time step.
186	DO m = 1, nleafages ! Loop over # leaf age classes
187	DO j = 2,nvm ! Loop over # PFTs
188	WHERE ( leaf_frac(:,j,m) .GT. min_stomate )
189
190	leaf_age(:,j,m) = leaf_age(:,j,m) + dt
191
192	ENDWHERE
193	ENDDO ! Loop over # PFTs
194
195	ENDDO ! Loop over # leaf age classes
196
197	!
198	!! 2.2 turnover between leaf age classes
199	! d_leaf_frac(:,:,m) = what leaves m-1 and goes into m
200	!
201
202	DO j = 2,nvm ! Loop over # PFTs
203
204	!! 2.2.1 fluxes
205
206	!! nothing goes into first age class
207	d_leaf_frac(:,j,1) = zero
208
209	!! for others age classes (what goes from m-1 to m)
210	DO m = 2, nleafages
211	!! leaf_timecst is defined in stomate_constants.f90 as the quotient of the critical leaf age per the number of age classes.
212	!! The critical leaf age is a PFT-dependent constant defined in stomate_constants.f90, that represents the leaf life span.
213	!! This time constant (leaf_timecst) determines the turnover between the nleafages different leaf age classes
214	!! (see section [118] in Krinner et al. (2005)).
215	d_leaf_frac(:,j,m) = leaf_frac(:,j,m-1) * dt/leaf_timecst(j)
216
217	ENDDO
218
219	!! 2.2.2 new leaf age in class
220	!! new age = ( old age * (old fraction - fractional loss) + fractional increase * age of the source class ) / new fraction
221	!! The leaf age of the youngest class (m=1) is updated into stomate_alloc
222	leaf_age_new(:,:) = zero
223
224	DO m = 2, nleafages-1 ! Loop over age classes
225	!! For all age classes except first and last
226	WHERE ( d_leaf_frac(:,j,m) .GT. min_stomate )
227
228	leaf_age_new(:,m) = ( ( (leaf_frac(:,j,m)- d_leaf_frac(:,j,m+1)) * leaf_age(:,j,m) ) + &
229	( d_leaf_frac(:,j,m) * leaf_age(:,j,m-1) ) ) / &
230	( leaf_frac(:,j,m) + d_leaf_frac(:,j,m)- d_leaf_frac(:,j,m+1) )
231
232	ENDWHERE
233
234	ENDDO ! Loop over age classes
235
236	!! For last age class, there is no leaf fraction leaving the class.
237
238	WHERE ( d_leaf_frac(:,j,nleafages) .GT. min_stomate )
239
240	leaf_age_new(:,nleafages) = ( ( leaf_frac(:,j,nleafages) * leaf_age(:,j,nleafages) ) + &
241	( d_leaf_frac(:,j,nleafages) * leaf_age(:,j,nleafages-1) ) ) / &
242	( leaf_frac(:,j,nleafages) + d_leaf_frac(:,j,nleafages) )
243
244	ENDWHERE
245
246	DO m = 2, nleafages ! Loop over age classes
247
248	WHERE ( d_leaf_frac(:,j,m) .GT. min_stomate )
249
250	leaf_age(:,j,m) = leaf_age_new(:,m)
251
252	ENDWHERE
253
254	ENDDO ! Loop over age classes
255
256	!! 2.2.3 calculate new fraction
257
258	DO m = 2, nleafages ! Loop over age classes
259
260	! where the change comes from
261	leaf_frac(:,j,m-1) = leaf_frac(:,j,m-1) - d_leaf_frac(:,j,m)
262
263	! where it goes to
264	leaf_frac(:,j,m) = leaf_frac(:,j,m) + d_leaf_frac(:,j,m)
265
266	ENDDO ! Loop over age classes
267
268	!! 2.2.4 renormalize fractions in order to prevent accumulation
269	! of numerical errors
270
271	! correct small negative values
272
273	DO m = 1, nleafages
274	leaf_frac(:,j,m) = MAX( zero, leaf_frac(:,j,m) )
275	ENDDO
276
277	! total of fractions, should be very close to one where there is leaf mass
278
279	sumfrac(:) = zero
280
281	DO m = 1, nleafages ! Loop over age classes
282
283	sumfrac(:) = sumfrac(:) + leaf_frac(:,j,m)
284
285	ENDDO ! Loop over age classes
286
287	! normalize
288
289	DO m = 1, nleafages ! Loop over age classes
290
291	WHERE ( sumfrac(:) .GT. min_stomate )
292
293	leaf_frac(:,j,m) = leaf_frac(:,j,m) / sumfrac(:)
294
295	ELSEWHERE
296
297	leaf_frac(:,j,m) = zero
298
299	ENDWHERE
300
301	ENDDO ! Loop over age classes
302
303	ENDDO ! Loop over PFTs
304
305	!
306	!! 3 calculate vmax as a function of the age
307	!
308
309	DO j = 2,nvm
310
311	vcmax(:,j) = zero
312	nue(:,j) = zero
313
314	! sum up over the different age classes
315	IF (ok_dgvm .AND. pheno_type(j)==1 .AND. leaf_tab(j)==2) THEN
316	! pheno_typ=evergreen and leaf_tab=needleleaf
317	vcmax(:,j) = Vcmax25(j)
318
319	ELSE
320	! for deciduous tree
321	DO m = 1, nleafages ! Loop over age classes
322
323	!
324	!! 3.1 efficiency in each of the age classes
325	!! it varies from vmax_offset to 1
326	!! linearly increases from vmax_offset to 1 for 0 < rel_age < leafage_firstmax
327	!! is 1 when leafage_firstmax < rel_age < leafage_lastmax
328	!! linearly decreases from 1 to vmax_offset for leafage_lastmax < rel_age < leafage_firstmax
329	!! vmax_offset for rel_age >= leafage_old
330	!! (Ishida et al., 1999)
331	rel_age(:) = leaf_age(:,j,m) / leafagecrit(j)
332
333	leaf_efficiency(:) = MAX( vmax_offset, MIN( un, &
334	vmax_offset + (un - vmax_offset) * rel_age(:) / leafage_firstmax, &
335	un - (un - vmax_offset) * ( rel_age(:) - leafage_lastmax ) / &
336	( leafage_old - leafage_lastmax ) ) )
337
338	!
339	!! 3.2 add to mean vmax
340	!
341	vcmax(:,j) = vcmax(:,j) + Vcmax25(j) * leaf_efficiency(:) * leaf_frac(:,j,m)
342
343
344	nue(:,j) = nue(:,j) + nue_opt(j) * leaf_efficiency(:) * leaf_frac(:,j,m)
345	ENDDO ! loop over age classes
346	ENDIF
347
348	ENDDO ! loop over PFTs
349
350	IF (printlev>=4) WRITE(numout,*) 'Leaving vmax'
351
352	END SUBROUTINE vmax
353
354	END MODULE stomate_vmax

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

Download in other formats: