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SURFEX v7.3
General documentation of Surfex
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SURFEX v7.3
General documentation of Surfex
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00001 ! ######### 00002 SUBROUTINE CANOPY_EVOL_WIND(KI,KLVL,PTSTEP,KIMPL,PWIND,PK,PDKDDVDZ, & 00003 PSFLUX_U,PFORC_U,PDFORC_UDU,PDZ,PDZF,PU,PUW, & 00004 PALFA,PBETA ) 00005 ! ######################################### 00006 ! 00007 !!**** *CANOPY_EVOL_WIND* - evolution of wind in canopy 00008 !! 00009 !! 00010 !! PURPOSE 00011 !! ------- 00012 !! 00013 !!** METHOD 00014 !! ------ 00015 !! 00016 !! EXTERNAL 00017 !! -------- 00018 !! 00019 !! 00020 !! IMPLICIT ARGUMENTS 00021 !! ------------------ 00022 !! 00023 !! REFERENCE 00024 !! --------- 00025 !! 00026 !! 00027 !! AUTHOR 00028 !! ------ 00029 !! V. Masson *Meteo France* 00030 !! 00031 !! MODIFICATIONS 00032 !! ------------- 00033 !! Original 07/2006 00034 !------------------------------------------------------------------------------- 00035 ! 00036 !* 0. DECLARATIONS 00037 ! ------------ 00038 ! 00039 USE MODI_CANOPY_EVOL_FIELD 00040 ! 00041 USE YOMHOOK ,ONLY : LHOOK, DR_HOOK 00042 USE PARKIND1 ,ONLY : JPRB 00043 ! 00044 IMPLICIT NONE 00045 ! 00046 !* 0.1 Declarations of arguments 00047 ! ------------------------- 00048 ! 00049 INTEGER, INTENT(IN) :: KI ! number of horizontal points 00050 INTEGER, INTENT(IN) :: KLVL ! number of levels in canopy 00051 REAL, INTENT(IN) :: PTSTEP ! time-step (s) 00052 INTEGER, INTENT(IN) :: KIMPL ! implicitation code: 00053 ! ! 1 : computes only alfa and beta coupling 00054 ! ! coefficients for all variables 00055 ! ! 2 : computes temporal evolution of the 00056 ! ! variables 00057 REAL, DIMENSION(KI), INTENT(IN) :: PWIND ! wind at forcing level (m/s) 00058 REAL, DIMENSION(KI,KLVL), INTENT(IN) :: PK ! mixing exchange coefficient (m2/s) 00059 REAL, DIMENSION(KI,KLVL), INTENT(IN) :: PDKDDVDZ ! derivative of mixing coefficient as a 00060 ! ! function of vertical gradient of wind 00061 ! ! (at mid levels) (m2) 00062 REAL, DIMENSION(KI), INTENT(IN) :: PSFLUX_U ! Surface flux u'w' (m2/s2) 00063 REAL, DIMENSION(KI,KLVL), INTENT(IN) :: PFORC_U ! tendency of wind due to canopy drag (m/s2) 00064 REAL, DIMENSION(KI,KLVL), INTENT(IN) :: PDFORC_UDU! formal derivative of the tendency of 00065 ! ! wind due to canopy drag (1/s) 00066 REAL, DIMENSION(KI,KLVL), INTENT(IN) :: PDZ ! deltaZ between canopy half levels, 00067 ! ! located at full levels (m) 00068 REAL, DIMENSION(KI,KLVL), INTENT(IN) :: PDZF ! deltaZ between canopy (full) levels, 00069 ! ! located at half levels (m) 00070 REAL, DIMENSION(KI,KLVL), INTENT(INOUT) :: PU ! wind speed at canopy levels (m/s) 00071 REAL, DIMENSION(KI,KLVL), INTENT(OUT) :: PUW ! turbulent flux (at half levels) (m2/s2) 00072 REAL, DIMENSION(KI), INTENT(OUT) :: PALFA ! V+(1) = alfa u'w' + beta 00073 REAL, DIMENSION(KI), INTENT(OUT) :: PBETA ! V+(1) = alfa u'w' + beta 00074 ! 00075 ! 00076 !* 0.2 Declarations of local variables 00077 ! ------------------------------- 00078 ! 00079 INTEGER :: JLAYER ! loop counter on layers 00080 ! 00081 REAL, DIMENSION(KI,KLVL) :: ZDUDZ ! dU/dz at mid levels 00082 REAL, DIMENSION(KI,KLVL) :: ZF ! turbulent flux at mid levels 00083 REAL, DIMENSION(KI,KLVL) :: ZDFDDVDZ ! derivative of turbulent flux as a 00084 ! ! function of vertical gradient of wind variable 00085 ! ! (at mid levels) 00086 REAL, DIMENSION(KI,KLVL) :: ZEXT ! external forcing at full levels 00087 REAL, DIMENSION(KI,KLVL) :: ZDEXTDV ! derivative of external forcing as a 00088 ! ! function of vertical variable 00089 ! ! (at full levels) 00090 REAL, DIMENSION(KI,KLVL) :: ZU ! work variable : wind at futur instant 00091 ! ! (or past at the end of the routine) 00092 REAL, DIMENSION(KI) :: ZDUADT ! dUa/dt at forcing level 00093 LOGICAL :: LIMPL 00094 REAL(KIND=JPRB) :: ZHOOK_HANDLE 00095 ! 00096 !------------------------------------------------------------------------------- 00097 ! 00098 ! 00099 !* 1. initializations 00100 ! --------------- 00101 ! 00102 !* external forces 00103 ! 00104 IF (LHOOK) CALL DR_HOOK('CANOPY_EVOL_WIND',0,ZHOOK_HANDLE) 00105 ZEXT = 0. 00106 ZDEXTDV = 0. 00107 ! 00108 !* coupling coefficient with the surface 00109 ! 00110 PALFA(:)=0. 00111 PBETA(:)=PU(:,1) 00112 ! 00113 !------------------------------------------------------------------------------- 00114 ! 00115 !* 5. Forcing due to drag (at full levels) 00116 ! ------------------- 00117 ! 00118 !* drag force by canopy 00119 ! 00120 ZEXT = ZEXT + PFORC_U(:,:) 00121 ! 00122 ZDEXTDV = ZDEXTDV + PDFORC_UDU(:,:) 00123 ! 00124 !------------------------------------------------------------------------------- 00125 ! 00126 !* 6. External forcing due to large-scale forces (at full levels) 00127 ! ------------------------------------------ 00128 ! 00129 ! 00130 !* forces due to large-scale forcing 00131 ! 00132 ! These are computed from wind evolution equation at forcing level : 00133 ! 00134 ! dUa/dt = Large_Scale_Forcing - d(u'w')/dz|z=forcing_level 00135 ! 00136 ! because vertical derivative of turbulent flux is not available at forcing 00137 ! level, one must make the assumption that the turbulent flux is uniform 00138 ! between the forcing level and the level just below. 00139 ! This means that one assume that the forcing layer is in the inertail sublayer 00140 ! (where turbulent fluxes are constant). 00141 ! 00142 ZDUADT(:) = ( PWIND(:) - PU(:,KLVL) ) /PTSTEP 00143 ! 00144 !* for smoother evolution at large time steps, does not include explicitely 00145 ! forcing term in lower layers 00146 DO JLAYER=1,KLVL-1 00147 ZEXT(:,JLAYER) = ZEXT(:,JLAYER) 00148 END DO 00149 00150 !* evolution of forcing layer forced by forcing... 00151 ZEXT(:,KLVL) = ZDUADT(:) 00152 ! 00153 CALL CANOPY_EVOL_FIELD(KI, KLVL, PTSTEP, KIMPL, PK, PDKDDVDZ, & 00154 PSFLUX_U, PFORC_U, PDFORC_UDU, PDZ, PDZF, & 00155 ZEXT, ZDEXTDV, PU, PUW, PALFA, PBETA ) 00156 ! 00157 !------------------------------------------------------------------------------- 00158 ! 00159 !* 10. Security at all levels : positivity of wind speed 00160 ! ---------------------- 00161 ! 00162 PU(:,:) = MAX(PU,0.) 00163 IF (LHOOK) CALL DR_HOOK('CANOPY_EVOL_WIND',1,ZHOOK_HANDLE) 00164 ! 00165 !---------------------------------------------------------------- 00166 ! 00167 END SUBROUTINE CANOPY_EVOL_WIND
1.8.0
