Line data Source code
1 :
2 : module ghg_data
3 :
4 : !------------------------------------------------------------------------------------------------
5 : ! Purpose:
6 : ! Provide default distributions of CH4, N2O, CFC11 and CFC12 to the radiation routines.
7 : ! **NOTE** CO2 is assumed by the radiation to a be constant value. This value is
8 : ! currently supplied directly by the chem_surfvals module.
9 : !
10 : ! Revision history:
11 : ! 2004-08-29 B. Eaton Create CAM interface to trcmix.
12 : !------------------------------------------------------------------------------------------------
13 :
14 : use shr_kind_mod, only: r8 => shr_kind_r8
15 : use ppgrid, only: pcols, pver, begchunk, endchunk
16 : use physics_types, only: physics_state
17 : use physconst, only: mwdry, mwch4, mwn2o, mwf11, mwf12, mwco2
18 : use chem_surfvals, only: chem_surfvals_get, chem_surfvals_co2_rad
19 : use cam_abortutils, only: endrun
20 : use error_messages, only: handle_err
21 :
22 :
23 : implicit none
24 : private
25 : save
26 :
27 : ! Public interfaces
28 : public ::&
29 : ghg_data_register, &! register ghg's with pbuf2d
30 : ghg_data_timestep_init ! place data model of ghg's in pbuf2d
31 :
32 : ! Private variables
33 :
34 : real(r8) :: rmwn2o ! = mwn2o/mwdry ! ratio of molecular weight n2o to dry air
35 : real(r8) :: rmwch4 ! = mwch4/mwdry ! ratio of molecular weight ch4 to dry air
36 : real(r8) :: rmwf11 ! = mwf11/mwdry ! ratio of molecular weight cfc11 to dry air
37 : real(r8) :: rmwf12 ! = mwf12/mwdry ! ratio of molecular weight cfc12 to dry air
38 : real(r8) :: rmwco2 ! = mwco2/mwdry ! ratio of molecular weights of co2 to dry air
39 :
40 : integer, parameter :: ncnst = 6 ! number of constituents
41 : character(len=8), dimension(ncnst), parameter :: &
42 : cnst_names = (/'N2O ', 'CH4 ', 'CFC11', 'CFC12', 'CO2 ', 'O2 '/) ! constituent names
43 : integer :: pbuf_idx(ncnst)
44 :
45 : !================================================================================================
46 : contains
47 : !================================================================================================
48 :
49 1536 : subroutine ghg_data_register()
50 : !-------------------------------------------------------------------------------
51 : ! register ghg's with pbuf2d
52 : !-------------------------------------------------------------------------------
53 : use physics_buffer, only : pbuf_add_field, dtype_r8
54 :
55 : integer iconst
56 :
57 :
58 10752 : do iconst = 1,ncnst
59 10752 : call pbuf_add_field(cnst_names(iconst),'physpkg',dtype_r8,(/pcols,pver/),pbuf_idx(iconst))
60 : enddo
61 :
62 1536 : end subroutine ghg_data_register
63 :
64 741888 : subroutine ghg_data_timestep_init(pbuf2d, state)
65 : !-------------------------------------------------------------------------------
66 : ! place data model of ghg's in pbuf2d at each timestep
67 : !-------------------------------------------------------------------------------
68 1536 : use ppgrid, only: begchunk, endchunk, pcols, pver
69 : use physics_types, only: physics_state
70 : use physics_buffer, only: physics_buffer_desc, pbuf_get_field, pbuf_get_chunk
71 :
72 :
73 : type(physics_state), intent(in), dimension(begchunk:endchunk) :: state
74 : type(physics_buffer_desc), pointer :: pbuf2d(:,:)
75 :
76 370944 : type(physics_buffer_desc), pointer :: pbuf_chnk(:)
77 370944 : real(r8), pointer :: tmpptr(:,:)
78 :
79 : integer iconst
80 : integer lchnk
81 :
82 370944 : rmwn2o = mwn2o/mwdry ! ratio of molecular weight n2o to dry air
83 370944 : rmwch4 = mwch4/mwdry ! ratio of molecular weight ch4 to dry air
84 370944 : rmwf11 = mwf11/mwdry ! ratio of molecular weight cfc11 to dry air
85 370944 : rmwf12 = mwf12/mwdry ! ratio of molecular weight cfc12 to dry air
86 370944 : rmwco2 = mwco2/mwdry ! ratio of molecular weights of co2 to dry air
87 :
88 2596608 : do iconst = 1,ncnst
89 : !$OMP PARALLEL DO PRIVATE (LCHNK,tmpptr,pbuf_chnk)
90 11568816 : do lchnk = begchunk, endchunk
91 8972208 : pbuf_chnk => pbuf_get_chunk(pbuf2d, lchnk)
92 8972208 : call pbuf_get_field(pbuf_chnk, pbuf_idx(iconst), tmpptr)
93 8972208 : call trcmix(cnst_names(iconst), state(lchnk)%ncol, &
94 : state(lchnk)%lat, state(lchnk)%pmid, &
95 20170080 : tmpptr)
96 : enddo
97 : enddo
98 :
99 741888 : end subroutine ghg_data_timestep_init
100 :
101 :
102 : !================================================================================================
103 :
104 8972208 : subroutine trcmix(name, ncol, clat, pmid, q)
105 : !-----------------------------------------------------------------------
106 : !
107 : ! Purpose:
108 : ! Specify zonal mean mass mixing ratios of CH4, N2O, CFC11 and
109 : ! CFC12
110 : !
111 : ! Method:
112 : ! Distributions assume constant mixing ratio in the troposphere
113 : ! and a decrease of mixing ratio in the stratosphere. Tropopause
114 : ! defined by ptrop. The scale height of the particular trace gas
115 : ! depends on latitude. This assumption produces a more realistic
116 : ! stratospheric distribution of the various trace gases.
117 : !
118 : ! Author: J. Kiehl
119 : !
120 : !-----------------------------------------------------------------------
121 :
122 : ! Arguments
123 : character(len=*), intent(in) :: name ! constituent name
124 : integer, intent(in) :: ncol ! number of columns
125 : real(r8), intent(in) :: clat(pcols) ! latitude in radians for columns
126 : real(r8), intent(in) :: pmid(pcols,pver) ! model pressures
127 : real(r8), intent(out) :: q(pcols,pver) ! constituent mass mixing ratio
128 :
129 : integer i ! longitude loop index
130 : integer k ! level index
131 :
132 : real(r8) coslat(pcols) ! cosine of latitude
133 : real(r8) dlat ! latitude in degrees
134 : real(r8) ptrop ! pressure level of tropopause
135 : real(r8) pratio ! pressure divided by ptrop
136 : real(r8) trop_mmr ! tropospheric mass mixing ratio
137 : real(r8) scale ! pressure scale height
138 : !-----------------------------------------------------------------------
139 :
140 149815008 : do i = 1, ncol
141 149815008 : coslat(i) = cos(clat(i))
142 : end do
143 :
144 8972208 : if (name == 'O2') then
145 :
146 662448024 : q = chem_surfvals_get('O2MMR')
147 :
148 7476840 : else if (name == 'CO2') then
149 :
150 662448024 : q = chem_surfvals_co2_rad()
151 :
152 5981472 : else if (name == 'CH4') then
153 :
154 : ! set tropospheric mass mixing ratios
155 1495368 : trop_mmr = rmwch4 * chem_surfvals_get('CH4VMR')
156 :
157 40374936 : do k = 1,pver
158 650693736 : do i = 1,ncol
159 : ! set stratospheric scale height factor for gases
160 610318800 : dlat = abs(57.2958_r8 * clat(i))
161 610318800 : if(dlat.le.45.0_r8) then
162 : scale = 0.2353_r8
163 : else
164 176314320 : scale = 0.2353_r8 + 0.0225489_r8 * (dlat - 45)
165 : end if
166 :
167 : ! pressure of tropopause
168 610318800 : ptrop = 250.0e2_r8 - 150.0e2_r8*coslat(i)**2.0_r8
169 :
170 : ! determine output mass mixing ratios
171 649198368 : if (pmid(i,k) >= ptrop) then
172 358986509 : q(i,k) = trop_mmr
173 : else
174 251332291 : pratio = pmid(i,k)/ptrop
175 251332291 : q(i,k) = trop_mmr * (pratio)**scale
176 : end if
177 : end do
178 : end do
179 :
180 4486104 : else if (name == 'N2O') then
181 :
182 : ! set tropospheric mass mixing ratios
183 1495368 : trop_mmr = rmwn2o * chem_surfvals_get('N2OVMR')
184 :
185 40374936 : do k = 1,pver
186 650693736 : do i = 1,ncol
187 : ! set stratospheric scale height factor for gases
188 610318800 : dlat = abs(57.2958_r8 * clat(i))
189 610318800 : if(dlat.le.45.0_r8) then
190 434004480 : scale = 0.3478_r8 + 0.00116_r8 * dlat
191 : else
192 176314320 : scale = 0.4000_r8 + 0.013333_r8 * (dlat - 45)
193 : end if
194 :
195 : ! pressure of tropopause
196 610318800 : ptrop = 250.0e2_r8 - 150.0e2_r8*coslat(i)**2.0_r8
197 :
198 : ! determine output mass mixing ratios
199 649198368 : if (pmid(i,k) >= ptrop) then
200 358986509 : q(i,k) = trop_mmr
201 : else
202 251332291 : pratio = pmid(i,k)/ptrop
203 251332291 : q(i,k) = trop_mmr * (pratio)**scale
204 : end if
205 : end do
206 : end do
207 :
208 2990736 : else if (name == 'CFC11') then
209 :
210 : ! set tropospheric mass mixing ratios
211 1495368 : trop_mmr = rmwf11 * chem_surfvals_get('F11VMR')
212 :
213 40374936 : do k = 1,pver
214 650693736 : do i = 1,ncol
215 : ! set stratospheric scale height factor for gases
216 610318800 : dlat = abs(57.2958_r8 * clat(i))
217 610318800 : if(dlat.le.45.0_r8) then
218 434004480 : scale = 0.7273_r8 + 0.00606_r8 * dlat
219 : else
220 176314320 : scale = 1.00_r8 + 0.013333_r8 * (dlat - 45)
221 : end if
222 :
223 : ! pressure of tropopause
224 610318800 : ptrop = 250.0e2_r8 - 150.0e2_r8*coslat(i)**2.0_r8
225 :
226 : ! determine output mass mixing ratios
227 649198368 : if (pmid(i,k) >= ptrop) then
228 358986509 : q(i,k) = trop_mmr
229 : else
230 251332291 : pratio = pmid(i,k)/ptrop
231 251332291 : q(i,k) = trop_mmr * (pratio)**scale
232 : end if
233 : end do
234 : end do
235 :
236 1495368 : else if (name == 'CFC12') then
237 :
238 : ! set tropospheric mass mixing ratios
239 1495368 : trop_mmr = rmwf12 * chem_surfvals_get('F12VMR')
240 :
241 40374936 : do k = 1,pver
242 650693736 : do i = 1,ncol
243 : ! set stratospheric scale height factor for gases
244 610318800 : dlat = abs(57.2958_r8 * clat(i))
245 610318800 : if(dlat.le.45.0_r8) then
246 434004480 : scale = 0.4000_r8 + 0.00222_r8 * dlat
247 : else
248 176314320 : scale = 0.50_r8 + 0.024444_r8 * (dlat - 45)
249 : end if
250 :
251 : ! pressure of tropopause
252 610318800 : ptrop = 250.0e2_r8 - 150.0e2_r8*coslat(i)**2.0_r8
253 :
254 : ! determine output mass mixing ratios
255 649198368 : if (pmid(i,k) >= ptrop) then
256 358986509 : q(i,k) = trop_mmr
257 : else
258 251332291 : pratio = pmid(i,k)/ptrop
259 251332291 : q(i,k) = trop_mmr * (pratio)**scale
260 : end if
261 : end do
262 : end do
263 :
264 : end if
265 :
266 370944 : end subroutine trcmix
267 :
268 : end module ghg_data
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