Home


About us
PALM
PALM-4U
Installation
Release notes
Documentation
Getting Help
Gallery
Developers area

Changes between Version 31 and Version 32 of doc/app/radiation_parameters


Ignore:
Timestamp:
Oct 25, 2018 10:38:33 AM (6 years ago)
Author:
resler
Comment:

--

Legend:

Unmodified
Added
Removed
Modified

  • doc/app/radiation_parameters

    v31 v32  
    3737|----------------
    3838{{{#!td style="vertical-align:top"
     39[=#albedo_lw_dif '''albedo_lw_dif''']
     40}}}
     41{{{#!td style="vertical-align:top"
     42R
     43}}}
     44{{{#!td style="vertical-align:top"
     45depending on [#albedo_type albedo_type]
     46}}}
     47{{{#!td
     48Surface albedo for longwave diffuse radiation for a solar angle of 60°.
     49}}}
     50|----------------
     51{{{#!td style="vertical-align:top"
     52[=#albedo_lw_dir '''albedo_lw_dir''']
     53}}}
     54{{{#!td style="vertical-align:top"
     55R
     56}}}
     57{{{#!td style="vertical-align:top"
     58depending on [#albedo_type albedo_type]
     59}}}
     60{{{#!td
     61Surface albedo for longwave direct radiation for a solar angle of 60°.
     62}}}
     63|----------------
     64{{{#!td style="vertical-align:top"
    3965[=#albedo_type '''albedo_type''']
    4066}}}
    … …  
    4672}}}
    4773{{{#!td
    48 This parameter controls the choice of the surface albedos for direct/diffuse/broadband albedo for a solar angle of 80° according to the following list of predefined land surfaces. 
    49 
    50 For radiation_scheme = 'rrtmg' the shortwave and longwave albedo values are used and the actual albedos are then calculated based on the current solar angle after Briegleb (1992). Setting on or more of the parameters [#albedo_lw_dif albedo_lw_dif], [#albedo_lw_dir albedo_lw_dir], [#albedo_sw_dif albedo_sw_dif], [#albedo_sw_dir albedo_sw_dir] will overwrite the respective values set by albedo_type. By default, [#albedo_lw_dif albedo_lw_dif] = [#albedo_lw_dir albedo_lw_dir] and [#albedo_sw_dif albedo_sw_dif] = [#albedo_sw_dir albedo_sw_dir]. Moreover, [#constant_albedo constant_albedo] = .T. will keep the albedos constant during the simulation. 
     74This parameter controls the choice of the surface albedos for direct/diffuse/broadband albedo for a solar angle of 80° according to the following list of predefined land surfaces.
     75
     76For radiation_scheme = 'rrtmg' the shortwave and longwave albedo values are used and the actual albedos are then calculated based on the current solar angle after Briegleb (1992). Setting on or more of the parameters [#albedo_lw_dif albedo_lw_dif], [#albedo_lw_dir albedo_lw_dir], [#albedo_sw_dif albedo_sw_dif], [#albedo_sw_dir albedo_sw_dir] will overwrite the respective values set by albedo_type. By default, [#albedo_lw_dif albedo_lw_dif] = [#albedo_lw_dir albedo_lw_dir] and [#albedo_sw_dif albedo_sw_dif] = [#albedo_sw_dir albedo_sw_dir]. Moreover, [#constant_albedo constant_albedo] = .T. will keep the albedos constant during the simulation.
    5177
    5278For radiation_scheme = 'clear-sky' the broadband albedo is used and does not vary in the course of the simulation.
    … …  
    95121|----------------
    96122{{{#!td style="vertical-align:top"
    97 [=#albedo_lw_dif '''albedo_lw_dif''']
     123[=#albedo_sw_dif '''albedo_sw_dif''']
    98124}}}
    99125{{{#!td style="vertical-align:top"
    … …  
    104130}}}
    105131{{{#!td
    106 Surface albedo for longwave diffuse radiation for a solar angle of 60°.
    107 }}}
    108 |----------------
    109 {{{#!td style="vertical-align:top"
    110 [=#albedo_lw_dir '''albedo_lw_dir''']
     132Surface albedo for shortwave diffuse radiation for a solar angle of 60°.
     133}}}
     134|----------------
     135{{{#!td style="vertical-align:top"
     136[=#albedo_sw_dir '''albedo_sw_dir''']
    111137}}}
    112138{{{#!td style="vertical-align:top"
    … …  
    117143}}}
    118144{{{#!td
    119 Surface albedo for longwave direct radiation for a solar angle of 60°.
    120 }}}
    121 |----------------
    122 {{{#!td style="vertical-align:top"
    123 [=#albedo_sw_dif '''albedo_sw_dif''']
    124 }}}
    125 {{{#!td style="vertical-align:top"
    126 R
    127 }}}
    128 {{{#!td style="vertical-align:top"
    129 depending on [#albedo_type albedo_type]
    130 }}}
    131 {{{#!td
    132 Surface albedo for shortwave diffuse radiation for a solar angle of 60°.
    133 }}}
    134 |----------------
    135 {{{#!td style="vertical-align:top"
    136 [=#albedo_sw_dir '''albedo_sw_dir''']
    137 }}}
    138 {{{#!td style="vertical-align:top"
    139 R
    140 }}}
    141 {{{#!td style="vertical-align:top"
    142 depending on [#albedo_type albedo_type]
    143 }}}
    144 {{{#!td
    145145Surface albedo for shortwave direct radiation for a solar angle of 60°.
    146146}}}
    … …  
    202202}}}
    203203{{{#!td
    204 Parameter to switch off longwave radiation.
     204Parameter to switch off the calculation of longwave radiation.
    205205
    206206When using RRTMG, longwave radiation calls can be switched off by setting {{{lw_radiation = .F.}}}.
    … …  
    208208|----------------
    209209{{{#!td style="vertical-align:top"
     210[=#max_raytracing_dist '''max_raytracing_dist''']
     211}}}
     212{{{#!td style="vertical-align:top"
     213R
     214}}}
     215{{{#!td style="vertical-align:top"
     216-999.0
     217}}}
     218{{{#!td
     219Maximum distance for raytracing (in meters).
     220
     221It is used to set the maximum distance allowed to consider the radiative exchange between two surfaces. This limits the number of surfaces view factors (VF) and hence save much memory by neglecting the very small VF resulting from the mutually visible far surfaces. At the end of VF calculations, the values will be scaled so that energy is conserved.
     222
     223If not set, the model will assume a value equal to double the urban surface layer height.
     224
     225Please note that the calculated FV needs to be higher than the threshold value set in [#min_irrf_value] in order to be considered.
     226}}}
     227|----------------
     228{{{#!td style="vertical-align:top"
     229[=#min_irrf_value '''min_irrf_value''']
     230}}}
     231{{{#!td style="vertical-align:top"
     232R
     233}}}
     234{{{#!td style="vertical-align:top"
     2351e-6
     236}}}
     237{{{#!td
     238Minimum potential irradiance factor value for raytracing.
     239
     240It is used to set the threshold to consider any view factor (VF) calculated between two surfaces. This limits the number of VF and hence save much memory by neglecting the very small VF resulting from the low mutual visiblity. At the end of VF calculations, the values will be scaled so that energy is conserved.
     241
     242Please note that this parameter will neglect any VF smaller than [#min_irrf_value] even though the coressponing surfaces are within the [#max_raytracing_dist].
     243}}}
     244|----------------
     245{{{#!td style="vertical-align:top"
     246[=#mrt_include_sw '''mrt_include_sw''']
     247}}}
     248{{{#!td style="vertical-align:top"
     249L
     250}}}
     251{{{#!td style="vertical-align:top"
     252.T.
     253}}}
     254{{{#!td
     255Parameter to include SW radiation into the mean radiant temperature (MRT) calculation. If you want to include [#rad_mrt_sw] in the output, then mrt_include_sw should set to TRUE.
     256}}}
     257|----------------
     258{{{#!td style="vertical-align:top"
    210259[=#mrt_nlevels '''mrt_nlevels''']
    211260}}}
    … …  
    218267{{{#!td
    219268Number of vertical boxes above surface for which to calculate mean radiant temperature (MRT).
     269
     270Note that this value is used also for calculation of MRT and PET values in the biometeorology module (bio_mrt and bio_pet output variables).
    220271}}}
    221272|----------------
    … …  
    234285|----------------
    235286{{{#!td style="vertical-align:top"
    236 [=#mrt_include_sw '''mrt_include_sw''']
    237 }}}
    238 {{{#!td style="vertical-align:top"
    239 L
    240 }}}
    241 {{{#!td style="vertical-align:top"
    242 .T.
    243 }}}
    244 {{{#!td
    245 Parameter to include SW radiation into the mean radiant temperature (MRT) calculation. If you want to include [#rad_mrt_sw] in the output, then mrt_include_sw should set to TRUE.
    246 }}}
    247 |----------------
    248 {{{#!td style="vertical-align:top"
    249287[=#net_radiation '''net_radiation''']
    250288}}}
    … …  
    260298|----------------
    261299{{{#!td style="vertical-align:top"
     300[=#nrefsteps '''nrefsteps''']
     301}}}
     302{{{#!td style="vertical-align:top"
     303I
     304}}}
     305{{{#!td style="vertical-align:top"
     3063
     307}}}
     308{{{#!td
     309Number of reflection steps to be performed inside RTM for the reflected short- and long-wave radiation between mutually visible surfaces.
     310
     311The default value {{{nrefsteps = 3}}} should be sufficient for typical urban area settings. The residual radiation after the nrefsteps reflections can checked in output variables usm_rad_ressw and usm_rad_reslw and the number of reflections should be adjusted accordingly.
     312}}}
     313|----------------
     314{{{#!td style="vertical-align:top"
     315[=#plant_lw_interact '''plant_lw_interact''']
     316}}}
     317{{{#!td style="vertical-align:top"
     318L
     319}}}
     320{{{#!td style="vertical-align:top"
     321.T.
     322}}}
     323{{{#!td
     324The parameter steers if plant canopy interacts with LW radiation. The value .T. enables absorbtion and emission of LW radiation by resolved plant canopy, if value is set .F. the plant canopy is transparent for LW radiation.
     325}}}
     326|----------------
     327{{{#!td style="vertical-align:top"
     328[=#rad_angular_discretization '''rad_angular_discretization''']
     329}}}
     330{{{#!td style="vertical-align:top"
     331L
     332}}}
     333{{{#!td style="vertical-align:top"
     334.T.
     335}}}
     336{{{#!td
     337Parameter to switch on using the angular discretization also for calculation of view factors between surfaces (reflected radiation). Diffuse radiation from sky is always calulated by this radiation regardless of setting of this parameter.
     338The recommended setting is to use angular discretization for regular simulations as it typically gives smaller discretization errors for near surfaces and it scales better for large domains. Setting {{{rad_angular_discretization = .TRUE.}}} requires {{{raytrace_mpi_rma = .TRUE.}}}.
     339}}}
     340|----------------
     341{{{#!td style="vertical-align:top"
     342[=#radiation_interactions_on '''radiation_interactions_on''']
     343}}}
     344{{{#!td style="vertical-align:top"
     345L
     346}}}
     347{{{#!td style="vertical-align:top"
     348.T.
     349}}}
     350{{{#!td
     351The setting of this parameter to .FALSE. forces not to activate RTM even if vertical urban/land surfaces or trees exist in the domain. In this case, all surfaces will receive radiation fluxes directly from the choosen radiation model (e.g. rrtmg or clear sky).
     352}}}
     353|----------------
     354{{{#!td style="vertical-align:top"
    262355[=#radiation_scheme '''radiation_scheme''']
    263356}}}
    … …  
    291384|----------------
    292385{{{#!td style="vertical-align:top"
     386[=#raytrace_discrete_azims '''raytrace_discrete_azims''']
     387}}}
     388{{{#!td style="vertical-align:top"
     389I
     390}}}
     391{{{#!td style="vertical-align:top"
     39280
     393}}}
     394{{{#!td
     395Number of horizontal discrete directions (azimuths) for angular discretization used to calculate the sky view factors, surface-surface view factor, and direct solar visibility for all surfaces.
     396}}}
     397|----------------
     398{{{#!td style="vertical-align:top"
     399[=#raytrace_discrete_elevs '''raytrace_discrete_elevs''']
     400}}}
     401{{{#!td style="vertical-align:top"
     402I
     403}}}
     404{{{#!td style="vertical-align:top"
     40540
     406}}}
     407{{{#!td
     408Number of vertical descrete elevations for angular discretization used to calculate the sky view factors, surface-surface view factor, and direct solar visibility for all surfaces.
     409}}}
     410|----------------
     411{{{#!td style="vertical-align:top"
     412[=#raytrace_mpi_rma '''raytrace_mpi_rma''']
     413}}}
     414{{{#!td style="vertical-align:top"
     415L
     416}}}
     417{{{#!td style="vertical-align:top"
     418.T.
     419}}}
     420{{{#!td
     421Parameter to enable the one-sided MPI communication to access LAD array and grid surfaces for raytracing. This parameter is only for debugging purposes and it should not be switched off in real simuations.
     422The setting .F. is not compatible with {{{rad_angular_discretization = .TRUE.}}}.
     423}}}
     424|----------------
     425{{{#!td style="vertical-align:top"
    293426[=#skip_time_do_radiation '''skip_time_do_radiation''']
    294427}}}
    … …  
    304437|----------------
    305438{{{#!td style="vertical-align:top"
     439[=#surface_reflections '''surface_reflections''']
     440}}}
     441{{{#!td style="vertical-align:top"
     442L
     443}}}
     444{{{#!td style="vertical-align:top"
     445.T.
     446}}}
     447{{{#!td
     448Parameter to switch off the surface-surface reflections in RTM. This parameter is intended only for special purposes (e.g. debugging, testing of sensitivities) and it should not be switched off for real simulations.
     449}}}
     450|----------------
     451{{{#!td style="vertical-align:top"
     452[=#svfnorm_report_thresh '''svfnorm_report_thresh''']
     453}}}
     454{{{#!td style="vertical-align:top"
     455R
     456}}}
     457{{{#!td style="vertical-align:top"
     4581e21
     459}}}
     460{{{#!td
     461Thresholds for reporting of normalization factors in calculation of surface view factors to report. It is not used for angular discretization ({{{rad_angular_discretization = .TRUE.}}}).
     462}}}
     463|----------------
     464{{{#!td style="vertical-align:top"
    306465[=#sw_radiation '''sw_radiation''']
    307466}}}
    … …  
    313472}}}
    314473{{{#!td
    315 Parameter to switch of shortwave radiation.
     474Parameter to switch off the calculation of shortwave radiation.
    316475
    317476When using RRTMG, shortwave radiation calls can be switched off by setting {{{sw_radiation = .F.}}}. Note that shortwave radiation is automatically switched off during nighttime.
    … …  
    332491Usually the radiation is called each [#dt_radiation], however in case of fast changes in the skin temperature, it is recommended to update the radiative fluxes independently from the prescribed radiation call frequency to prevent oscillations. The value of the temperature threshold used is 0.2 °K.
    333492}}}
    334 |----------------
    335 {{{#!td style="vertical-align:top"
    336 [=#max_raytracing_dist '''max_raytracing_dist''']
    337 }}}
    338 {{{#!td style="vertical-align:top"
    339 R
    340 }}}
    341 {{{#!td style="vertical-align:top"
    342 -999.0
    343 }}}
    344 {{{#!td
    345 Maximum distance for raytracing (in meters).
    346 
    347 It is used to set the maximum distance allowed to consider the radiative exchange between two surfaces. This limits the number of surfaces view factors (VF) and hence save much memory by neglecting the very small VF resulting from the mutually visible far surfaces. At the end of VF calculations, the values will be scaled so that energy is conserved.
    348 
    349 If not set, the model will assume a value equal to double the urban surface layer height.
    350 
    351 Please note that the calculated FV needs to be higher than the threshold value set in [#min_irrf_value] in order to be considered.
    352 }}}
    353 |----------------
    354 {{{#!td style="vertical-align:top"
    355 [=#min_irrf_value '''min_irrf_value''']
    356 }}}
    357 {{{#!td style="vertical-align:top"
    358 R
    359 }}}
    360 {{{#!td style="vertical-align:top"
    361 1e-6
    362 }}}
    363 {{{#!td
    364 Minimum potential irradiance factor value for raytracing.
    365 
    366 It is used to set the threshold to consider any view factor (VF) calculated between two surfaces. This limits the number of VF and hence save much memory by neglecting the very small VF resulting from the low mutual visiblity. At the end of VF calculations, the values will be scaled so that energy is conserved.
    367 
    368 Please note that this parameter will neglect any VF smaller than [#min_irrf_value] even though the coressponing surfaces are within the [#max_raytracing_dist].
    369 }}}
    370 |----------------
    371 {{{#!td style="vertical-align:top"
    372 [=#nrefsteps '''nrefsteps''']
    373 }}}
    374 {{{#!td style="vertical-align:top"
    375 I
    376 }}}
    377 {{{#!td style="vertical-align:top"
    378 0
    379 }}}
    380 {{{#!td
    381 Number of reflection steps to be performed to accound for the refelcted short- and longwave between musually visible surfaces.
    382 
    383 Although the effect of reflection depends on the surface characteristics (albedo, emissivity, etc.), however for typical urban areas it is recommended to set {{{nrefsteps = 3}}} because the effect of reflection after 3 reflections is negligible.
    384 }}}
    385 |----------------
    386 {{{#!td style="vertical-align:top"
    387 [=#raytrace_mpi_rma '''raytrace_mpi_rma''']
    388 }}}
    389 {{{#!td style="vertical-align:top"
    390 L
    391 }}}
    392 {{{#!td style="vertical-align:top"
    393 .F.
    394 }}}
    395 {{{#!td
    396 Parameter to use One-sided communication (MPI-RMA) to access LAD array and grid surfaces for raytracing.
    397 
    398 For large domain it is recommended to use MPI-RMA to access LAD array and a window of surfaces for raytracing instead of allocating the global arraies for each processor. This saves memory and allows for simulations of large domains.
    399 
    400 Please note:
    401 - When using fixed resolution discretization of view factors (i.e. {{{rad_angular_discretization = .TRUE.}}}), raytrace_mpi_rma MUST be set to .TRUE. when parallelization is applied. See [#rad_angular_discretization].
    402 - For Intel compiler, if you observe performance degradation with an MPI application that utilizes the RMA functionality (i.e. {{{rma_lad_raytrace = .TRUE.}}}), you are recommended to set {{{I_MPI_SCALABLE_OPTIMIZATION = 0}}} to get a performance gain.
    403 }}}
    404 |----------------
    405 {{{#!td style="vertical-align:top"
    406 [=#surface_reflections '''surface_reflections''']
    407 }}}
    408 {{{#!td style="vertical-align:top"
    409 L
    410 }}}
    411 {{{#!td style="vertical-align:top"
    412 .T.
    413 }}}
    414 {{{#!td
    415 Parameter to consider surface-surface reflections.
    416 
    417 It is not recommended to set {{{surface_reflections = .F.}}} because When it switched to off, only the effect of building and tree shadows will be considered and all reflection processes will be disabled. However fewer no surface-surface VFs are caclulated and less memory requirement is expected.
    418 }}}
    419 |----------------
    420 {{{#!td style="vertical-align:top"
    421 [=#svfnorm_report_thresh '''svfnorm_report_thresh''']
    422 }}}
    423 {{{#!td style="vertical-align:top"
    424 R
    425 }}}
    426 {{{#!td style="vertical-align:top"
    427 1e21
    428 }}}
    429 {{{#!td
    430 thresholds of surface view factors normalization values to report.
    431 
    432 This array contains 30 values of the histogram steps of logged VF normalization values to show the VF distribution.
    433 }}}
    434 |----------------
    435 {{{#!td style="vertical-align:top"
    436 [=#radiation_interactions_on '''radiation_interactions_on''']
    437 }}}
    438 {{{#!td style="vertical-align:top"
    439 L
    440 }}}
    441 {{{#!td style="vertical-align:top"
    442 .T.
    443 }}}
    444 {{{#!td
    445 Parameter to force RTM activiation regardless to vertical urban/land surface and trees.
    446 
    447 RTM is usually set according to the existance of vertical urban/land surface or trees. If set to FALSE, no RTM is used even when there are vertical urban/land surface or trees in the domain. This simply means that all surfaces will receive radiation fluxes directly from the radiation model without considering other radiation processes such as reflections.
    448 }}}
    449 |----------------
    450 {{{#!td style="vertical-align:top"
    451 [=#rad_angular_discretization '''rad_angular_discretization''']
    452 }}}
    453 {{{#!td style="vertical-align:top"
    454 L
    455 }}}
    456 {{{#!td style="vertical-align:top"
    457 .T.
    458 }}}
    459 {{{#!td
    460 Parameter to use fixed resolution discretization of view factors for reflected radiation (as opposed to all mutually visible pairs).
    461 
    462 Please note:
    463 - When using fixed resolution discretization of view factors (i.e. {{{rad_angular_discretization = .TRUE.}}}), raytrace_mpi_rma MUST be set to .TRUE. when parallelization is applied. See [#raytrace_mpi_rma].
    464 }}}
    465 |----------------
    466 {{{#!td style="vertical-align:top"
    467 [=#raytrace_discrete_azims '''raytrace_discrete_azims''']
    468 }}}
    469 {{{#!td style="vertical-align:top"
    470 I
    471 }}}
    472 {{{#!td style="vertical-align:top"
    473 80
    474 }}}
    475 {{{#!td
    476 Number of discretization steps for azimuth (out of 360 degrees) used to discretize surfaces to calculate the sky view factors, surface-surface view factor, and direct solar visibility for all surfaces.
    477 }}}
    478 |----------------
    479 {{{#!td style="vertical-align:top"
    480 [=#raytrace_discrete_elevs '''raytrace_discrete_elevs''']
    481 }}}
    482 {{{#!td style="vertical-align:top"
    483 I
    484 }}}
    485 {{{#!td style="vertical-align:top"
    486 40
    487 }}}
    488 {{{#!td
    489 Number of discretization steps for elevation  used to discretize surfaces to calculate the sky view factors, surface-surface view factor, and direct solar visibility for all surfaces.
    490 }}}
                                                                                                                                                                                                                                                                                                                                                                               
  | Impressum | ©Leibniz Universität Hannover |