1 | MODULE sbcblk_algo_ice_lu12 |
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2 | !!====================================================================== |
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3 | !! *** MODULE sbcblk_algo_ice_lu12 *** |
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4 | !! Computes turbulent components of surface fluxes over sea-ice |
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5 | !! |
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6 | !! Lüpkes, C., Gryanik, V. M., Hartmann, J., and Andreas, E. L. ( 2012), A parametrization, based on sea ice morphology, |
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7 | !! of the neutral atmospheric drag coefficients for weather prediction and climate models, J. Geophys. Res., 117, D13112, |
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8 | !! doi:10.1029/2012JD017630. |
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9 | !! |
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10 | !! => Despite the fact that the sea-ice concentration (frice) must be provided, |
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11 | !! only transfer coefficients, and air temp. + hum. height adjustement |
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12 | !! over ice are returned/performed. |
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13 | !! ==> 'frice' is only here to estimate the form drag caused by sea-ice... |
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14 | !! |
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15 | !! Routine turb_ice_lu12 maintained and developed in AeroBulk |
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16 | !! (https://github.com/brodeau/aerobulk/) |
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17 | !! |
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18 | !! Author: Laurent Brodeau, Summer 2020 |
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19 | !! |
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20 | !!---------------------------------------------------------------------- |
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21 | USE par_kind, ONLY: wp |
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22 | USE par_oce, ONLY: jpi, jpj |
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23 | USE phycst ! physical constants |
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24 | USE sbc_phy ! Catalog of functions for physical/meteorological parameters in the marine boundary layer |
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25 | USE sbcblk_algo_ice_cdn |
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26 | |
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27 | IMPLICIT NONE |
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28 | PRIVATE |
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29 | |
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30 | PUBLIC :: turb_ice_lu12 |
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31 | |
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32 | REAL(wp), PARAMETER :: rz0_i_s_0 = 0.69e-3_wp ! Eq.(43) of Lupkes & Gryanik (2015) [m] => to estimate CdN10 for skin drag! |
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33 | REAL(wp), PARAMETER :: rz0_i_f_0 = 4.54e-4_wp ! bottom p.562 MIZ [m] (LG15) |
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34 | |
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35 | !!---------------------------------------------------------------------- |
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36 | CONTAINS |
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37 | |
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38 | SUBROUTINE turb_ice_lu12( zt, zu, Ts_i, t_zt, qs_i, q_zt, U_zu, frice, & |
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39 | & Cd_i, Ch_i, Ce_i, t_zu_i, q_zu_i, & |
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40 | & CdN, ChN, CeN, xz0, xu_star, xL, xUN10 ) |
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41 | !!---------------------------------------------------------------------- |
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42 | !! *** ROUTINE turb_ice_lu12 *** |
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43 | !! |
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44 | !! ** Purpose : Computes turbulent transfert coefficients of surface |
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45 | !! fluxes according to: |
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46 | !! Lüpkes, C., Gryanik, V. M., Hartmann, J., and Andreas, E. L. ( 2012), |
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47 | !! A parametrization, based on sea ice morphology, of the neutral |
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48 | !! atmospheric drag coefficients for weather prediction and climate models, |
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49 | !! J. Geophys. Res., 117, D13112, doi:10.1029/2012JD017630. |
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50 | !! |
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51 | !! INPUT : |
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52 | !! ------- |
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53 | !! * zt : height for temperature and spec. hum. of air [m] |
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54 | !! * zu : height for wind speed (usually 10m) [m] |
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55 | !! * Ts_i : surface temperature of sea-ice [K] |
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56 | !! * t_zt : potential air temperature at zt [K] |
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57 | !! * qs_i : saturation specific humidity at temp. Ts_i over ice [kg/kg] |
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58 | !! * q_zt : specific humidity of air at zt [kg/kg] |
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59 | !! * U_zu : scalar wind speed at zu [m/s] |
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60 | !! * frice : sea-ice concentration (fraction) |
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61 | !! |
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62 | !! OUTPUT : |
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63 | !! -------- |
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64 | !! * Cd_i : drag coefficient over sea-ice |
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65 | !! * Ch_i : sensible heat coefficient over sea-ice |
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66 | !! * Ce_i : sublimation coefficient over sea-ice |
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67 | !! * t_zu_i : pot. air temp. adjusted at zu over sea-ice [K] |
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68 | !! * q_zu_i : spec. hum. of air adjusted at zu over sea-ice [kg/kg] |
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69 | !! |
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70 | !! OPTIONAL OUTPUT: |
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71 | !! ---------------- |
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72 | !! * CdN : neutral-stability drag coefficient |
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73 | !! * ChN : neutral-stability sensible heat coefficient |
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74 | !! * CeN : neutral-stability evaporation coefficient |
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75 | !! * xz0 : return the aerodynamic roughness length (integration constant for wind stress) [m] |
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76 | !! * xu_star : return u* the friction velocity [m/s] |
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77 | !! * xL : return the Obukhov length [m] |
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78 | !! * xUN10 : neutral wind speed at 10m [m/s] |
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79 | !! |
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80 | !! ** Author: L. Brodeau, January 2020 / AeroBulk (https://github.com/brodeau/aerobulk/) |
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81 | !!---------------------------------------------------------------------------------- |
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82 | REAL(wp), INTENT(in ) :: zt ! height for t_zt and q_zt [m] |
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83 | REAL(wp), INTENT(in ) :: zu ! height for U_zu [m] |
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84 | REAL(wp), INTENT(in ), DIMENSION(jpi,jpj) :: Ts_i ! ice surface temperature [Kelvin] |
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85 | REAL(wp), INTENT(in ), DIMENSION(jpi,jpj) :: t_zt ! potential air temperature [Kelvin] |
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86 | REAL(wp), INTENT(in ), DIMENSION(jpi,jpj) :: qs_i ! sat. spec. hum. at ice/air interface [kg/kg] |
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87 | REAL(wp), INTENT(in ), DIMENSION(jpi,jpj) :: q_zt ! spec. air humidity at zt [kg/kg] |
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88 | REAL(wp), INTENT(in ), DIMENSION(jpi,jpj) :: U_zu ! relative wind module at zu [m/s] |
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89 | REAL(wp), INTENT(in ), DIMENSION(jpi,jpj) :: frice ! sea-ice concentration (fraction) |
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90 | REAL(wp), INTENT(out), DIMENSION(jpi,jpj) :: Cd_i ! drag coefficient over sea-ice |
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91 | REAL(wp), INTENT(out), DIMENSION(jpi,jpj) :: Ch_i ! transfert coefficient for heat over ice |
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92 | REAL(wp), INTENT(out), DIMENSION(jpi,jpj) :: Ce_i ! transfert coefficient for sublimation over ice |
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93 | REAL(wp), INTENT(out), DIMENSION(jpi,jpj) :: t_zu_i ! pot. air temp. adjusted at zu [K] |
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94 | REAL(wp), INTENT(out), DIMENSION(jpi,jpj) :: q_zu_i ! spec. humidity adjusted at zu [kg/kg] |
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95 | !!---------------------------------------------------------------------------------- |
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96 | REAL(wp), INTENT(out), DIMENSION(jpi,jpj), OPTIONAL :: CdN |
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97 | REAL(wp), INTENT(out), DIMENSION(jpi,jpj), OPTIONAL :: ChN |
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98 | REAL(wp), INTENT(out), DIMENSION(jpi,jpj), OPTIONAL :: CeN |
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99 | REAL(wp), INTENT(out), DIMENSION(jpi,jpj), OPTIONAL :: xz0 ! Aerodynamic roughness length [m] |
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100 | REAL(wp), INTENT(out), DIMENSION(jpi,jpj), OPTIONAL :: xu_star ! u*, friction velocity |
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101 | REAL(wp), INTENT(out), DIMENSION(jpi,jpj), OPTIONAL :: xL ! zeta (zu/L) |
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102 | REAL(wp), INTENT(out), DIMENSION(jpi,jpj), OPTIONAL :: xUN10 ! Neutral wind at zu |
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103 | !!---------------------------------------------------------------------------------- |
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104 | REAL(wp), DIMENSION(:,:), ALLOCATABLE :: dt_zu, dq_zu, z0 |
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105 | REAL(wp), DIMENSION(:,:), ALLOCATABLE :: Ubzu |
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106 | !! |
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107 | LOGICAL :: lreturn_cdn=.FALSE., lreturn_chn=.FALSE., lreturn_cen=.FALSE. |
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108 | LOGICAL :: lreturn_z0=.FALSE., lreturn_ustar=.FALSE., lreturn_L=.FALSE., lreturn_UN10=.FALSE. |
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109 | !! |
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110 | CHARACTER(len=40), PARAMETER :: crtnm = 'turb_ice_lu12@sbcblk_algo_ice_lu12.f90' |
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111 | !!---------------------------------------------------------------------------------- |
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112 | ALLOCATE ( Ubzu(jpi,jpj) ) |
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113 | ALLOCATE ( dt_zu(jpi,jpj), dq_zu(jpi,jpj), z0(jpi,jpj) ) |
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114 | |
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115 | lreturn_cdn = PRESENT(CdN) |
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116 | lreturn_chn = PRESENT(ChN) |
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117 | lreturn_cen = PRESENT(CeN) |
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118 | lreturn_z0 = PRESENT(xz0) |
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119 | lreturn_ustar = PRESENT(xu_star) |
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120 | lreturn_L = PRESENT(xL) |
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121 | lreturn_UN10 = PRESENT(xUN10) |
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122 | |
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123 | !! Scalar wind speed cannot be below 0.2 m/s |
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124 | Ubzu = MAX( U_zu, wspd_thrshld_ice ) |
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125 | |
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126 | !! First guess of temperature and humidity at height zu: |
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127 | t_zu_i = MAX( t_zt , 100._wp ) ! who knows what's given on masked-continental regions... |
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128 | q_zu_i = MAX( q_zt , 0.1e-6_wp ) ! " |
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129 | |
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130 | !! Air-Ice & Air-Sea differences (and we don't want them to be 0!) |
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131 | dt_zu = t_zu_i - Ts_i ; dt_zu = SIGN( MAX(ABS(dt_zu),1.E-6_wp), dt_zu ) |
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132 | dq_zu = q_zu_i - qs_i ; dq_zu = SIGN( MAX(ABS(dq_zu),1.E-9_wp), dq_zu ) |
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133 | |
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134 | !! To estimate CDN10_skin: |
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135 | !! we use the method that comes in LG15, i.e. by starting from a default roughness length z0 for skin drag: |
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136 | |
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137 | Ce_i(:,:) = rz0_i_s_0 !! temporary array to contain roughness length for skin drag ! |
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138 | |
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139 | |
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140 | !! Method #1: |
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141 | !Cd_i(:,:) = Cd_from_z0( zu, Ce_i(:,:) ) + CdN10_f_LU13( frice(:,:) ) |
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142 | !IF( lreturn_cdfrm ) CdN_frm = CdN10_f_LU13( frice(:,:) ) |
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143 | !PRINT *, 'LOLO: estimate of Cd_f_i method #1 =>', CdN10_f_LU13( frice(:,:) ); PRINT *, '' |
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144 | |
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145 | !! Method #2: |
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146 | !! We need an estimate of z0 over water: |
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147 | !z0_w(:,:) = z0_from_Cd( zu, CD_N10_NCAR(Ubzu) ) |
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148 | !!PRINT *, 'LOLO: estimate of z0_w =>', z0_w |
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149 | !Cd_i(:,:) = Cd_from_z0( zu, Ce_i(:,:) ) + CdN10_f_LU12( frice(:,:), z0_w(:,:) ) |
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150 | !IF( lreturn_cdfrm ) CdN_frm = CdN10_f_LU12( frice(:,:), z0_w(:,:) ) |
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151 | !! N10 skin drag N10 form drag |
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152 | |
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153 | !! Method #3: |
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154 | !Cd_i(:,:) = Cd_from_z0( zu, Ce_i(:,:) ) + CdN10_f_LU12_eq36( frice(:,:) ) |
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155 | !IF( lreturn_cdfrm ) CdN_frm = CdN10_f_LU12_eq36( frice(:,:) ) |
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156 | !PRINT *, 'LOLO: estimate of Cd_f_i method #2 =>', CdN10_f_LU12( frice(:,:), z0_w(:,:) ) |
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157 | |
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158 | !! Method #4: |
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159 | !! using eq.21 of LG15 instead: |
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160 | z0(:,:) = rz0_i_f_0 |
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161 | !Cd_i(:,:) = Cd_from_z0( zu, Ce_i(:,:) ) + CdN_f_LG15( zu, frice(:,:), z0(:,:) ) / frice(:,:) |
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162 | Cd_i(:,:) = Cd_from_z0( zu, Ce_i(:,:) ) + CdN_f_LG15( zu, frice(:,:), z0(:,:) ) !/ frice(:,:) |
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163 | !IF( lreturn_cdfrm ) CdN_frm = CdN_f_LG15( zu, frice(:,:), z0(:,:) ) |
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164 | |
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165 | |
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166 | Ch_i(:,:) = Cd_i(:,:) |
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167 | Ce_i(:,:) = Cd_i(:,:) |
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168 | |
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169 | IF( lreturn_cdn ) CdN = Cd_i(:,:) |
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170 | IF( lreturn_chn ) ChN = Ch_i(:,:) |
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171 | IF( lreturn_cen ) CeN = Ce_i(:,:) |
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172 | |
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173 | IF( lreturn_z0 ) xz0 = z0_from_Cd( zu, Cd_i ) |
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174 | IF( lreturn_ustar ) xu_star = SQRT(Cd_i)*Ubzu |
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175 | IF( lreturn_L ) xL = 1./One_on_L(t_zu_i, q_zu_i, SQRT(Cd_i)*Ubzu, & |
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176 | & Cd_i/SQRT(Cd_i)*dt_zu, Cd_i/SQRT(Cd_i)*dq_zu) |
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177 | IF( lreturn_UN10 ) xUN10 = SQRT(Cd_i)*Ubzu/vkarmn * LOG( 10._wp / z0_from_Cd( zu, Cd_i ) ) |
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178 | |
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179 | DEALLOCATE ( dt_zu, dq_zu, z0 ) |
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180 | DEALLOCATE ( Ubzu ) |
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181 | |
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182 | END SUBROUTINE turb_ice_lu12 |
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183 | |
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184 | !!====================================================================== |
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185 | END MODULE sbcblk_algo_ice_lu12 |
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