-
Notifications
You must be signed in to change notification settings - Fork 9
/
README
327 lines (283 loc) · 18.8 KB
/
README
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
! path: $Source$
! author: $Author: mike $
! revision: $Revision: 11744 $
! created: $Date: 2009-11-12 15:52:26 -0500 (Thu, 12 Nov 2009) $
! ---------------------------------------------------------------------
RRTMG_LW: Longwave Radiative Transfer Model for GCMs
Atmospheric and Environmental Research,
131 Hartwell Avenue, Lexington, MA 02421
Original version: E. J. Mlawer, et al. (AER)
Revision for GCMs: Michael J. Iacono (AER)
Contact: Michael J. Iacono (E-mail: miacono@aer.com)
Web Sites: https://github.com/AER-RC/RRTMG_LW
https://www.rtweb.aer.com
References (RRTMG_LW/RRTM_LW):
Iacono, M.J., J.S. Delamere, E.J. Mlawer, M.W. Shephard,
S.A. Clough, and W.D. Collins, Radiative forcing by long-
lived greenhouse gases: Calculations with the AER radiative
transfer models, J. Geophys. Res., 113, D13103, doi:
10.1029/2008JD009944, 2008.
Clough, S.A., M.W. Shephard, E.J. Mlawer, J.S. Delamere,
M.J. Iacono, K. Cady-Pereira, S. Boukabara, and P.D. Brown,
Atmospheric radiative transfer modeling: a summary of the
AER codes, J. Quant., Spectrosc. Radiat. Transfer, 91,
233-244, 2005.
Iacono, M.J., J.S. Delamere, E.J. Mlawer, and S.A. Clough,
Evaluation of upper tropospheric water vapor in the NCAR
Community Climate Model (CCM3) using modeled and observed
HIRS radiances. J. Geophys. Res., 108(D2), 4037, doi:10.1029/
2002JD002539, 2003.
Iacono, M.J., E.J. Mlawer, S.A. Clough, and J.-J. Morcrette,
Impact of an improved longwave radiation model, RRTM, on the
energy budget and thermodynamic properties of the NCAR Community
Climate Model, CCM3, J. Geophys. Res., 105, 14873-14890, 2000.
Mlawer, E.J., S.J. Taubman, P.D. Brown, M.J. Iacono, and S.A.
Clough: Radiative transfer for inhomogeneous atmospheres: RRTM,
a validated correlated-k model for the longwave. J. Geophys.
Res., 102, 16663-16682, 1997.
Reference (McICA):
Pincus, R., H. W. Barker, and J.-J. Morcrette, A fast, flexible,
approximation technique for computing radiative transfer in
inhomogeneous cloud fields, J. Geophys. Res., 108(D13), 4376,
doi:10.1029/2002JD003322, 2003.
Reference (Latitude-Varying Decorrelation Length):
Oreopoulos, L., D. Lee, Y.C. Sud, and M.J. Suarez, Radiative
impacts of cloud heterogeneity and overlap in an atmospheric
General Circulation Model, Atmos. Chem. Phys., 12, 9097-9111,
doi:10.5194/acp-12-9097-2012, 2012.
******************************************************************************
This package contains the source code and sample makefiles necessary to run the
latest version of RRTMG_LW, a correlated k-distribution longwave radiative transfer
model developed at AER for application to GCMs. This version of RRTMG_LW has
been modified from the standard RRTM_LW distributed by AER to enhance its
performance for use within general circulation models. This code has also been
modified to utilize updated FORTRAN coding features. Two modes of operation
are possible: 1) RRTMG_LW can be run as a column model using the input files
and source modules described below, or 2) it can be implemented as a subroutine
into an atmospheric general circulation model or single column model.
The version of RRTMG_LW provided here has been modified from the standard
RRTM_LW to enhance performance with little effect on the accuracy. The total
number of g-points used has been reduced from 256 to 140. Fluxes are accurate
to within 0.5 W/m2 and cooling rate within 0.1 K/day relative to the standard
RRTM_LW, which is itself accurate to within 1 W/m2 of the data-validated
line-by-line radiative transfer model, LBLRTM. Required absorption coefficient
input data can be read in either from data stored within the code or from an
external netCDF file as selected in the makefile.
This model can also utilize McICA, the Monte-Carlo Independent Column
Approximation, to represent sub-grid scale cloud variability such as cloud
fraction and cloud overlap. If the McICA option is selected to model a cloudy
profile in column mode, then the model will run stochastically, and the output
fluxes and heating rates will be an average over 200 samples. In GCM mode,
the code will calcualte a single column per profile, and the statistical basis
is provided by the spatial and temporal dimensions of the 3-D calculations.
Several cloud overlap methods are available for partial cloudiness including
maximum-random, exponential, and exponential-random.
The model includes an optional feature to provide simultaneously with a
normal forward calculation the change in upward flux with respect to surface
temperature for each model level. This option is controlled by the input
flag, idrv. Setting this flag to 1 will output dF/dT for total sky and
clear sky in GCM mode in new output arrays duflx_dt and duflxc_dt. These
can be utilized to approximate the change in upward flux for a change in
surface temperature only at time intervals between full radiation calls.
In single column mode, setting idrv to 1 requires the extra input of a dT
change in surface temperature relative to the input surface temperature, and
the provided dT will be applied to the flux derivative to output a modified
upward flux profile for that dT change in surface temperature. The default
idrv setting of 0 provides the original forward radiative transfer calculation.
*************************
RRTMG_LW : Column Version
*************************
DOCUMENTATION:
The following text files (some in the /doc directory) provide information
on release updates and on using and running RRTMG_LW:
README : Basic code package information (this file)
release_notes.txt : Code archive update information
rrtmg_lw_instructions.txt : Input instructions for files INPUT_RRTM, IN_CLD_RRTM
and IN_AER_RRTM
SOURCE CODE:
The following source files (in the /src directory) must be used to run
RRTMG_LW in stand-alone mode as a column model (the utility files are stored
separately in the /aer_rt_utils directory):
rrtmg_lw.1col.f90 : RRTMG_LW main module
rrtmg_lw_cldprop.f90 : Calculation of cloud optical properties
rrtmg_lw_cldprmc.f90 : Calculation of cloud optical properties (McICA)
rrtmg_lw_init.f90 : RRTMG_LW initialization routine; reduces g-intervals
from 256 to 140
rrtmg_lw_k_g.f90 : Absorption coefficient data file
rrtmg_lw_read_nc.f90 : Optional absorption coefficient data netCDF input
rrtmg_lw_rtrn.f90 : Calculation of clear and cloudy radiative transfer
using random cloud overlap
rrtmg_lw_rtrnmr.f90 : Calculation of clear and cloudy radiative transfer
using maximum-random cloud overlap
rrtmg_lw_rtrnmc.f90 : Calculation of clear and cloudy radiative transfer
using McICA (with user-selectable overlap method)
rrtmg_lw_setcoef.f90 : Set up routine
rrtmg_lw_taumol.f90 : Calculation of optical depths and Planck fractions
for each spectral band
mcica_random_numbers.f90 : Random number generator for McICA
mcica_subcol_gen_lw.1col.f90 : Sub-column generator for McICA
rrtatm.f : Process user-defined input data files
extra.f : Process input data files
util_**.f : Utilities (available for multiple platforms)
The following module files (in the /modules directory) must be used to run
RRTMG_LW in stand-alone mode as a column model (these must be compiled before the
source code files):
parkind.f90 : real and integer kind type parameters
parrrtm.f90 : main configuration parameters
rrlw_cld.f90 : cloud property coefficients
rrlw_con.f90 : constants
rrlw_kg**.f90 : absorption coefficient arrays for 16 spectral bands
rrlw_ncpar.f90 : parameters for netCDF input data option
rrlw_ref.f90 : reference atmosphere data arrays
rrlw_tbl.f90 : exponential look up table arrays
rrlw_vsn.f90 : version number information
rrlw_wvn.f90 : spectral band and g-interval array information
INPUT DATA:
The following file (in the /data directory) is the optional netCDF input file
containing absorption coefficient and other input data for the model.
The file is used if keyword KGSRC is set for netCDF input in the makefile.
rrtmg_lw.nc : Optional netCDF input data file
MAKEFILES:
The following files (in the /build/makefiles directory) can be used to compile
RRTMG_LW in stand-alone mode as a column model on various platforms. Link
one of these into the /build directory to compile.
make_rrtmg_lw_sgi : Sample makefile for SGI
make_rrtmg_lw_sun : Sample makefile for SUN
make_rrtmg_lw_linux_pgi : Sample makefile for LINUX (PGI compiler)
make_rrtmg_lw_aix_xlf90 : Sample makefile for AIX (XLF90 compiler)
make_rrtmg_lw_OS_X_g95 : Sample makefile for OS_X (G95 compiler)
make_rrtmg_lw_OS_X_ibm_xl : Sample makefile for OS_X (IBM XL compiler)
SAMPLE INPUT/OUTPUT:
Several sample input and output files are included in the /runs_std_atm directory.
Note that user-defined profiles may be used for as many as 200 layers.
INPUT_RRTM : Required input file for (clear sky) atmospheric
specification
IN_CLD_RRTM : Required input file for cloud specification if clouds
are present
IN_AER_RRTM : Required input file for aerosol specification if aerosols
are present
OUTPUT_RRTM : Main output file for atmospheric fluxes and heating rates
input_rrtm_ICRCCM_sonde : Sample radiosonde-style input profile for clear sky
input_rrtm.MLS-clr : Sample 51 layer mid-latitude summer standard atmosphere
for clear sky
input_rrtm.MLS-cld-imca0-icld2
: Sample 51 layer mid-latitude summer standard atmosphere
with cloud flag turned on and maximum-random cloud
overlap selected (without McICA)
input_rrtm.MLS-cld-imca1-icld2
: Sample 51 layer mid-latitude summer standard atmosphere
with cloud flag turned on and maximum-random cloud
overlap selected (with McICA)
input_rrtm.MLS-cld-imca1-icld4-idcor0
: Sample 51 layer mid-latitude summer standard atmosphere
with cloud flag turned on and exponential cloud overlap
and constant decorrelation length selected (with McICA)
input_rrtm.MLS-cld-imca1-icld5-idcor0
: Sample 51 layer mid-latitude summer standard atmosphere
with cloud flag turned on and exponential-random cloud overlap
and constant decorrelation length selected (with McICA)
input_rrtm.MLS-cld-imca1-icld5-idcor1
: Sample 51 layer mid-latitude summer standard atmosphere
with cloud flag turned on and exponential-random cloud overlap
and varying decorrelation length selected (with McICA)
input_rrtm.MLS-clr-aer12 : Sample 51 layer mid-latitude summer standard atmosphere
with aersol flag set
input_rrtm.MLS-clr-xsec : Sample 51 layer mid-latitude summer standard atmosphere
with cross-section input (CFCs, etc.)
input_rrtm.MLS-clr-idrv1 : Sample 51 layer mid-latitude summer standard atmosphere
with derivative option set to provide modified upward
fluxes for the provided change in surface temperature
input_rrtm.MLW-clr : Sample 51 layer mid-latitude winter standard atmosphere
input_rrtm.SAW-clr : Sample 51 layer sub-arctic winter standard atmosphere
input_rrtm.TROP-clr : Sample 51 layer tropical standard atmosphere
in_cld_rrtm-cld5 : Sample cloud input file
in_cld_rrtm-cld7 : Sample cloud input file
in_aer_rrtm-aer12 : Sample aerosol input file
script.run_std_atm : UNIX script for running the full suite of example cases,
which will put the output into similarly named files
prefixed with output_rrtm*
INSTRUCTIONS FOR COMPILING AND RUNNING THE COLUMN MODEL:
1) In the /build directory, link one of the makefiles from the /makefile sub-directory
into /build/make.build. To use the optional netCDF input file, switch the keyword
"KGSRC" in the makefile from "dat" to "nc". Compile the model with "make -f make.build"
2) Link the executable to, for example, "rrtmg_lw" in the /runs_std_atm directory
3) If the optional netCDF input file was selected when compiling, link the file
/data/rrtmg_lw.nc into the /runs_std_atm directory.
4) In the /runs_std_atm directory, run the UNIX script "./script.run_std_atm" to run
the full suite of example cases. To run a single case, modify INPUT_RRTM following the
instructions in /doc/rrtmg_lw_instructions.txt", or copy one of the example input_rrtm*
files into INPUT_RRTM. If clouds are selected (ICLD > 0), then modify IN_CLD_RRTM or
copy one of the in_cld_rrtm* files into IN_CLD_RRTM. If aerosols are selected
(IAER > 0), then modify IN_AER_RRTM or set it to the sample file in_aer_rrtm-aer12.
5) In column mode, if McICA is selected (IMCA=1) with partial cloudiness defined, then
RRTMG_LW will run the case 200 times to derive adequate statistics, and the average
of the 200 samples will be written to the output file, OUTPUT_RRTM.
**********************
RRTMG_LW : GCM version
**********************
DOCUMENTATION:
README : Basic code package information (this file)
SOURCE CODE:
The following source files (in the /src directory) must be used to run RRTMG_LW
as a callable subroutine:
NOTE: Only one of rrtmg_lw_k_g.f90 or rrtmg_lw_read_nc.f90 is required.
rrtmg_lw_rad.f90 : RRTMG_LW main module (with McICA)
rrtmg_lw_rad.nomcica.f90 : Optional RRTMG_LW main module (without McICA only)
rrtmg_lw_cldprop.f90 : Calculation of cloud optical properties
rrtmg_lw_cldprmc.f90 : Calculation of cloud optical properties (McICA)
rrtmg_lw_init.f90 : RRTMG_LW initialization routine; reduces g-intervals
from 256 to 140; (This has to run only once and should
be installed in the GCM initialization section)
rrtmg_lw_k_g.f90 : Absorption coefficient data file
rrtmg_lw_read_nc.f90 : Optional absorption coefficient data netCDF input
rrtmg_lw_rtrn.f90 : Calculation of clear and cloudy radiative transfer
using random cloud overlap
rrtmg_lw_rtrnmr.f90 : Calculation of clear and cloudy radiative transfer
using maximum-random cloud overlap
rrtmg_lw_rtrnmc.f90 : Calculation of clear and cloudy radiative transfer
using McICA (with selectable overlap method)
rrtmg_lw_setcoef.f90 : Set up routine
rrtmg_lw_taumol.f90 : Calculation of optical depths and Planck fractions for
each spectral band
mcica_random_numbers.f90 : Random number generator for McICA
mcica_subcol_gen_lw.f90 : Sub-column generator for McICA (must be called in GCM
just before call to RRTMG)
The following module files (in the /modules directory) must be used to run
RRTMG_LW as a callable subroutine (these must be compiled before the source code)
parkind.f90 : real and integer kind type parameters
parrrtm.f90 : main configuration parameters
rrlw_cld.f90 : cloud property coefficients
rrlw_con.f90 : constants
rrlw_kg**.f90 : absorption coefficient arrays for 16 spectral bands
rrlw_ncpar.f90 : parameters for netCDF input data option
rrlw_ref.f90 : reference atmosphere data arrays
rrlw_tbl.f90 : look up table arrays
rrlw_vsn.f90 : version number information
rrlw_wvn.f90 : spectral band and g-interval array information
INPUT DATA:
The following file (in the /data directory) is the optional netCDF file
containing absorption coefficient and other input data for the model.
The file is used if source file rrtmg_lw_read_nc.f90 is used in place
of rrtmg_lw_k_g.f90 (only one or the other is required).
rrtmg_lw.nc : Optional netCDF input data file
NOTES ON RUNNING THE GCM (SUBROUTINE) VERSION OF THE CODE:
1) The module rrtmg_lw_init.f90 is the initialization routine that has to be
called only once. The call to this subroutine should be moved to the
initialization section of the host model if RRTMG_LW is called by a GCM or SCM.
2) The number of model layers and the number of columns to be looped over should
be passed into RRTMG_LW through the subroutine call along with the other model
profile arrays.
3) To utilize McICA, the sub-column generator (mcica_subcol_gen_lw.f90) must be
implemented in the GCM so that it is called just before RRTMG_LW. The cloud
overlap method is selected using the input flag, icld. If either exponential
(ICLD=4) or exponential-random (ICLD=5) cloud overlap is selected, then the
subroutine "get_alpha" must be called prior to calling "mcica_subcol_lw" to
define the vertical correlation parameter, alpha, needed for those overlap
methods. Also for those methods, use the input flag "idcor" to select the use
of either a constant or latitude-varying decorrelation length.
If McICA is utilized, this will run only a single statistical sample per
model grid box. There are two options for the random number generator used
with McICA, which is selected with the variable irnd in mcica_subcol_gen_lw.f90.
When using McICA, then the main module is rrtmg_lw_rad.f90. If McICA is not used,
then the main module is rrtmg_lw_rad.nomcica.f90 and the cloud overlap method is
selected by setting flag icld.