Ignore:
Timestamp:
Jul 19, 2018 9:08:49 PM (3 years ago)
Author:
maronga
Message:

added local free convection velocity scale in calculation of horizontal wind at first grid level

File:
1 edited

Legend:

Unmodified
Added
Removed
  • palm/trunk/SOURCE/surface_layer_fluxes_mod.f90

    r3152 r3157  
    2626! -----------------
    2727! $Id$
     28! Added local free convection velocity scale w_lfc in calculation of uvw_abs.
     29! This can be switche on/off by the user via the flag namelist parameter
     30! use_free_convection_scaling
     31!
     32! 3152 2018-07-19 13:26:52Z suehring
    2833! q_surface is now part of surface structure
    2934!
     
    246251               most_method, neutral, passive_scalar, pt_surface, q_surface,    &
    247252               run_coupled, surface_pressure, simulated_time, terminate_run,   &
    248                time_since_reference_point, urban_surface, zeta_max, zeta_min
     253               time_since_reference_point, urban_surface,                      &
     254               use_free_convection_scaling, zeta_max, zeta_min
    249255
    250256    USE grid_variables,                                                        &
     
    952958!------------------------------------------------------------------------------!
    953959    SUBROUTINE calc_uvw_abs
    954 
     960   
    955961       IMPLICIT NONE
    956962
     
    961967       INTEGER(iwp) ::  m             !< running index surface elements
    962968
     969       REAL(wp)     :: w_lfc          !< local free convection velocity scale
    963970!
    964971!--    ibit is 1 for upward-facing surfaces, zero for downward-facing surfaces.
     
    970977          j   = surf%j(m)
    971978          k   = surf%k(m)
     979       
     980!
     981!--       Calculate free convection velocity scale w_lfc is
     982!--       use_free_convection_scaling = .T.. This will maintain a horizontal
     983!--       velocity even for very weak wind convective conditions. SIGN is used
     984!--       to set w_lfc to zero under stable conditions.
     985          IF ( use_free_convection_scaling )  THEN
     986             w_lfc = ABS(g / surf%pt1(m) * surf%z_mo(m) * surf%shf(m))
     987             w_lfc = ( 0.5_wp * ( w_lfc + SIGN(w_lfc,surf%shf(m)) ) )**(0.33333_wp)
     988          ELSE
     989             w_lfc = 0.0_wp
     990          ENDIF
     991
    972992!
    973993!--       Compute the absolute value of the horizontal velocity.
     
    9911011                                           ) * ibit                            &
    9921012                                         )                                     &
    993                               )**2                                             &
     1013                              )**2  + w_lfc**2                                 &
    9941014                                )
    9951015
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