1 | MODULE icedyn_rdgrft |
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2 | !!====================================================================== |
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3 | !! *** MODULE icedyn_rdgrft *** |
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4 | !! sea-ice : Mechanical impact on ice thickness distribution |
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5 | !!====================================================================== |
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6 | !! History : LIM ! 2006-02 (M. Vancoppenolle) Original code |
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7 | !! 3.2 ! 2009-07 (M. Vancoppenolle, Y. Aksenov, G. Madec) bug correction in smsw & sfx_dyn |
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8 | !! 4.0 ! 2011-02 (G. Madec) dynamical allocation |
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9 | !!---------------------------------------------------------------------- |
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10 | #if defined key_lim3 |
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11 | !!---------------------------------------------------------------------- |
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12 | !! 'key_lim3' ESIM sea-ice model |
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13 | !!---------------------------------------------------------------------- |
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14 | !! ice_dyn_rdgrft : ridging/rafting of sea ice |
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15 | !! ice_dyn_rdgrft_init : initialization of ridging/rafting of sea ice |
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16 | !! ice_strength : ice strength calculation |
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17 | !!---------------------------------------------------------------------- |
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18 | USE dom_oce ! ocean domain |
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19 | USE phycst ! physical constants (ocean directory) |
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20 | USE sbc_oce , ONLY : sss_m, sst_m ! surface boundary condition: ocean fields |
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21 | USE ice1D ! sea-ice: thermodynamics |
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22 | USE ice ! sea-ice: variables |
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23 | USE icevar ! sea-ice: operations |
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24 | USE icectl ! sea-ice: control prints |
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25 | ! |
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26 | USE in_out_manager ! I/O manager |
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27 | USE iom ! I/O manager library |
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28 | USE lib_mpp ! MPP library |
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29 | USE lib_fortran ! fortran utilities (glob_sum + no signed zero) |
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30 | USE lbclnk ! lateral boundary conditions (or mpp links) |
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31 | USE timing ! Timing |
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32 | |
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33 | IMPLICIT NONE |
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34 | PRIVATE |
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35 | |
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36 | PUBLIC ice_dyn_rdgrft ! called by icestp |
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37 | PUBLIC ice_dyn_rdgrft_init ! called by icedyn |
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38 | PUBLIC ice_strength ! called by icedyn_rhg_evp |
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39 | |
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40 | ! Variables shared among ridging subroutines |
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41 | REAL(wp), ALLOCATABLE, SAVE, DIMENSION(:,:) :: asum ! sum of total ice and open water area |
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42 | REAL(wp), ALLOCATABLE, SAVE, DIMENSION(:,:) :: aksum ! ratio of area removed to area ridged |
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43 | REAL(wp), ALLOCATABLE, SAVE, DIMENSION(:,:,:) :: apartf ! participation function; fraction of ridging/closing associated w/ category n |
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44 | REAL(wp), ALLOCATABLE, SAVE, DIMENSION(:,:,:) :: hrmin ! minimum ridge thickness |
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45 | REAL(wp), ALLOCATABLE, SAVE, DIMENSION(:,:,:) :: hrmax ! maximum ridge thickness |
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46 | REAL(wp), ALLOCATABLE, SAVE, DIMENSION(:,:,:) :: hraft ! thickness of rafted ice |
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47 | REAL(wp), ALLOCATABLE, SAVE, DIMENSION(:,:,:) :: hi_hrdg ! thickness of ridging ice / mean ridge thickness |
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48 | REAL(wp), ALLOCATABLE, SAVE, DIMENSION(:,:,:) :: aridge ! participating ice ridging |
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49 | REAL(wp), ALLOCATABLE, SAVE, DIMENSION(:,:,:) :: araft ! participating ice rafting |
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50 | ! |
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51 | REAL(wp), PARAMETER :: hrdg_hi_min = 1.1_wp ! min ridge thickness multiplier: min(hrdg/hi) |
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52 | REAL(wp), PARAMETER :: hi_hrft = 0.5_wp ! rafting multipliyer: (hi/hraft) |
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53 | REAL(wp) :: zdrho ! |
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54 | ! |
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55 | ! ** namelist (namdyn_rdgrft) ** |
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56 | LOGICAL :: ln_str_H79 ! ice strength parameterization (Hibler79) |
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57 | REAL(wp) :: rn_pstar ! determines ice strength, Hibler JPO79 |
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58 | REAL(wp) :: rn_crhg ! determines changes in ice strength |
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59 | LOGICAL :: ln_str_R75 ! ice strength parameterization (Rothrock75) |
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60 | REAL(wp) :: rn_perdg ! ridging work divided by pot. energy change in ridging |
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61 | REAL(wp) :: rn_csrdg ! fraction of shearing energy contributing to ridging |
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62 | LOGICAL :: ln_partf_lin ! participation function linear (Thorndike et al. (1975)) |
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63 | REAL(wp) :: rn_gstar ! fractional area of young ice contributing to ridging |
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64 | LOGICAL :: ln_partf_exp ! participation function exponential (Lipscomb et al. (2007)) |
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65 | REAL(wp) :: rn_astar ! equivalent of G* for an exponential participation function |
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66 | LOGICAL :: ln_ridging ! ridging of ice or not |
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67 | REAL(wp) :: rn_hstar ! thickness that determines the maximal thickness of ridged ice |
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68 | REAL(wp) :: rn_porordg ! initial porosity of ridges (0.3 regular value) |
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69 | REAL(wp) :: rn_fsnwrdg ! fractional snow loss to the ocean during ridging |
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70 | REAL(wp) :: rn_fpndrdg ! fractional pond loss to the ocean during ridging |
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71 | LOGICAL :: ln_rafting ! rafting of ice or not |
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72 | REAL(wp) :: rn_hraft ! threshold thickness (m) for rafting / ridging |
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73 | REAL(wp) :: rn_craft ! coefficient for smoothness of the hyperbolic tangent in rafting |
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74 | REAL(wp) :: rn_fsnwrft ! fractional snow loss to the ocean during rafting |
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75 | REAL(wp) :: rn_fpndrft ! fractional pond loss to the ocean during rafting |
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76 | ! |
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77 | !!---------------------------------------------------------------------- |
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78 | !! NEMO/ICE 4.0 , NEMO Consortium (2017) |
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79 | !! $Id: icedyn_rdgrft.F90 8378 2017-07-26 13:55:59Z clem $ |
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80 | !! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt) |
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81 | !!---------------------------------------------------------------------- |
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82 | CONTAINS |
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83 | |
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84 | INTEGER FUNCTION ice_dyn_rdgrft_alloc() |
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85 | !!---------------------------------------------------------------------! |
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86 | !! *** ROUTINE ice_dyn_rdgrft_alloc *** |
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87 | !!---------------------------------------------------------------------! |
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88 | ALLOCATE( asum (jpi,jpj) , apartf (jpi,jpj,0:jpl) , aksum (jpi,jpj) , & |
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89 | & hrmin(jpi,jpj,jpl) , hraft (jpi,jpj,jpl) , aridge(jpi,jpj,jpl) , & |
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90 | & hrmax(jpi,jpj,jpl) , hi_hrdg(jpi,jpj,jpl) , araft (jpi,jpj,jpl) , STAT=ice_dyn_rdgrft_alloc ) |
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91 | |
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92 | IF( lk_mpp ) CALL mpp_sum ( ice_dyn_rdgrft_alloc ) |
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93 | IF( ice_dyn_rdgrft_alloc /= 0 ) CALL ctl_warn( 'ice_dyn_rdgrft_alloc: failed to allocate arrays' ) |
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94 | ! |
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95 | END FUNCTION ice_dyn_rdgrft_alloc |
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96 | |
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97 | |
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98 | SUBROUTINE ice_dyn_rdgrft( kt ) |
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99 | !!---------------------------------------------------------------------! |
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100 | !! *** ROUTINE ice_dyn_rdgrft *** |
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101 | !! |
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102 | !! ** Purpose : computes the mechanical redistribution of ice thickness |
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103 | !! |
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104 | !! ** Method : Steps : |
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105 | !! 1) Thickness categories boundaries, ice / o.w. concentrations |
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106 | !! Ridge preparation |
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107 | !! 2) Dynamical inputs (closing rate, divu_adv, opning) |
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108 | !! 3) Ridging iteration |
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109 | !! 4) Ridging diagnostics |
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110 | !! 5) Heat, salt and freshwater fluxes |
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111 | !! 6) Compute increments of tate variables and come back to old values |
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112 | !! |
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113 | !! References : Flato, G. M., and W. D. Hibler III, 1995, JGR, 100, 18,611-18,626. |
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114 | !! Hibler, W. D. III, 1980, MWR, 108, 1943-1973, 1980. |
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115 | !! Rothrock, D. A., 1975: JGR, 80, 4514-4519. |
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116 | !! Thorndike et al., 1975, JGR, 80, 4501-4513. |
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117 | !! Bitz et al., JGR, 2001 |
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118 | !! Amundrud and Melling, JGR 2005 |
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119 | !! Babko et al., JGR 2002 |
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120 | !! |
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121 | !! This routine is based on CICE code and authors William H. Lipscomb, |
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122 | !! and Elizabeth C. Hunke, LANL are gratefully acknowledged |
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123 | !!--------------------------------------------------------------------! |
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124 | INTEGER, INTENT(in) :: kt ! number of iteration |
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125 | !! |
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126 | INTEGER :: ji, jj, jk, jl ! dummy loop index |
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127 | INTEGER :: niter ! local integer |
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128 | INTEGER :: iterate_ridging ! if =1, repeat the ridging |
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129 | REAL(wp) :: zfac ! local scalar |
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130 | REAL(wp), DIMENSION(jpi,jpj) :: closing_net ! net rate at which area is removed (1/s) |
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131 | ! ! (ridging ice area - area of new ridges) / dt |
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132 | REAL(wp), DIMENSION(jpi,jpj) :: divu_adv ! divu as implied by transport scheme (1/s) |
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133 | REAL(wp), DIMENSION(jpi,jpj) :: opning ! rate of opening due to divergence/shear |
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134 | REAL(wp), DIMENSION(jpi,jpj) :: closing_gross ! rate at which area removed, not counting area of new ridges |
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135 | ! |
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136 | INTEGER, PARAMETER :: nitermax = 20 |
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137 | !!----------------------------------------------------------------------------- |
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138 | ! controls |
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139 | IF( nn_timing == 1 ) CALL timing_start('icedyn_rdgrft') ! timing |
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140 | IF( ln_icediachk ) CALL ice_cons_hsm(0, 'icedyn_rdgrft', rdiag_v, rdiag_s, rdiag_t, rdiag_fv, rdiag_fs, rdiag_ft) ! conservation |
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141 | |
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142 | IF( kt == nit000 ) THEN |
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143 | IF(lwp) WRITE(numout,*) |
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144 | IF(lwp) WRITE(numout,*)'ice_dyn_rdgrft: ice ridging and rafting' |
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145 | IF(lwp) WRITE(numout,*)'~~~~~~~~~~~~~' |
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146 | ! |
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147 | zdrho = 0.5 * grav * (rau0-rhoic) * rhoic * r1_rau0 ! proport const for PE |
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148 | ! |
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149 | ENDIF |
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150 | |
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151 | !-----------------------------------------------------------------------------! |
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152 | ! 1) Thickness categories boundaries, ice / o.w. concentrations, init_ons |
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153 | !-----------------------------------------------------------------------------! |
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154 | ! |
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155 | CALL rdgrft_prep ! prepare ridging |
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156 | ! |
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157 | DO jj = 1, jpj ! Initialize arrays. |
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158 | DO ji = 1, jpi |
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159 | !-----------------------------------------------------------------------------! |
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160 | ! 2) Dynamical inputs (closing rate, divu_adv, opning) |
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161 | !-----------------------------------------------------------------------------! |
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162 | ! |
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163 | ! 2.1 closing_net |
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164 | !----------------- |
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165 | ! Compute the net rate of closing due to convergence |
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166 | ! and shear, based on Flato and Hibler (1995). |
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167 | ! |
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168 | ! The energy dissipation rate is equal to the net closing rate |
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169 | ! times the ice strength. |
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170 | ! |
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171 | ! NOTE: The NET closing rate is equal to the rate that open water |
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172 | ! area is removed, plus the rate at which ice area is removed by |
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173 | ! ridging, minus the rate at which area is added in new ridges. |
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174 | ! The GROSS closing rate is equal to the first two terms (open |
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175 | ! water closing and thin ice ridging) without the third term |
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176 | ! (thick, newly ridged ice). |
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177 | |
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178 | closing_net(ji,jj) = rn_csrdg * 0.5_wp * ( delta_i(ji,jj) - ABS( divu_i(ji,jj) ) ) - MIN( divu_i(ji,jj), 0._wp ) |
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179 | |
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180 | ! 2.2 divu_adv |
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181 | !-------------- |
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182 | ! Compute divu_adv, the divergence rate given by the transport/ |
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183 | ! advection scheme, which may not be equal to divu as computed |
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184 | ! from the velocity field. |
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185 | ! |
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186 | ! If divu_adv < 0, make sure the closing rate is large enough |
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187 | ! to give asum = 1.0 after ridging. |
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188 | |
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189 | divu_adv(ji,jj) = ( 1._wp - asum(ji,jj) ) * r1_rdtice ! asum found in ridgeprep |
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190 | |
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191 | IF( divu_adv(ji,jj) < 0._wp ) closing_net(ji,jj) = MAX( closing_net(ji,jj), -divu_adv(ji,jj) ) |
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192 | |
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193 | ! 2.3 opning |
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194 | !------------ |
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195 | ! Compute the (non-negative) opening rate that will give asum = 1.0 after ridging. |
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196 | opning(ji,jj) = closing_net(ji,jj) + divu_adv(ji,jj) |
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197 | END DO |
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198 | END DO |
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199 | |
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200 | !-----------------------------------------------------------------------------! |
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201 | ! 3) Ridging iteration |
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202 | !-----------------------------------------------------------------------------! |
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203 | niter = 1 ! iteration counter |
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204 | iterate_ridging = 1 |
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205 | |
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206 | DO WHILE ( iterate_ridging > 0 .AND. niter < nitermax ) |
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207 | |
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208 | ! 3.1 closing_gross |
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209 | !-----------------------------------------------------------------------------! |
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210 | ! Based on the ITD of ridging and ridged ice, convert the net |
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211 | ! closing rate to a gross closing rate. |
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212 | ! NOTE: 0 < aksum <= 1 |
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213 | closing_gross(:,:) = closing_net(:,:) / aksum(:,:) |
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214 | |
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215 | ! correction to closing rate and opening if closing rate is excessive |
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216 | !--------------------------------------------------------------------- |
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217 | ! Reduce the closing rate if more than 100% of the open water |
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218 | ! would be removed. Reduce the opening rate proportionately. |
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219 | DO jj = 1, jpj |
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220 | DO ji = 1, jpi |
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221 | zfac = ( opning(ji,jj) - apartf(ji,jj,0) * closing_gross(ji,jj) ) * rdt_ice |
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222 | IF ( zfac < 0._wp .AND. zfac > - ato_i(ji,jj) ) THEN ! would lead to negative ato_i |
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223 | opning(ji,jj) = apartf(ji,jj,0) * closing_gross(ji,jj) - ato_i(ji,jj) * r1_rdtice |
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224 | ELSEIF( zfac > 0._wp .AND. zfac > ( asum(ji,jj) - ato_i(ji,jj) ) ) THEN ! would lead to ato_i > asum |
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225 | opning(ji,jj) = apartf(ji,jj,0) * closing_gross(ji,jj) + ( asum(ji,jj) - ato_i(ji,jj) ) * r1_rdtice |
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226 | ENDIF |
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227 | END DO |
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228 | END DO |
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229 | |
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230 | ! correction to closing rate / opening if excessive ice removal |
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231 | !--------------------------------------------------------------- |
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232 | ! Reduce the closing rate if more than 100% of any ice category |
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233 | ! would be removed. Reduce the opening rate proportionately. |
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234 | DO jl = 1, jpl |
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235 | DO jj = 1, jpj |
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236 | DO ji = 1, jpi |
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237 | zfac = apartf(ji,jj,jl) * closing_gross(ji,jj) * rdt_ice |
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238 | IF( zfac > a_i(ji,jj,jl) ) THEN |
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239 | closing_gross(ji,jj) = closing_gross(ji,jj) * a_i(ji,jj,jl) / zfac |
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240 | ENDIF |
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241 | END DO |
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242 | END DO |
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243 | END DO |
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244 | |
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245 | ! 3.2 Redistribute area, volume, and energy. |
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246 | !-----------------------------------------------------------------------------! |
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247 | CALL rdgrft_shift( opning, closing_gross ) |
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248 | |
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249 | ! 3.3 Compute total area of ice plus open water after ridging. |
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250 | !-----------------------------------------------------------------------------! |
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251 | ! This is in general not equal to one because of divergence during transport |
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252 | asum(:,:) = ato_i(:,:) + SUM( a_i, dim=3 ) |
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253 | |
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254 | ! 3.4 Do we keep on iterating? |
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255 | !-----------------------------------------------------------------------------! |
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256 | ! Check whether asum = 1. If not (because the closing and opening |
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257 | ! rates were reduced above), ridge again with new rates. |
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258 | iterate_ridging = 0 |
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259 | DO jj = 1, jpj |
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260 | DO ji = 1, jpi |
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261 | IF( ABS( asum(ji,jj) - 1._wp ) < epsi10 ) THEN |
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262 | closing_net(ji,jj) = 0._wp |
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263 | opning (ji,jj) = 0._wp |
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264 | ato_i (ji,jj) = MAX( 0._wp, 1._wp - SUM( a_i(ji,jj,:) ) ) |
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265 | ELSE |
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266 | iterate_ridging = 1 |
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267 | divu_adv (ji,jj) = ( 1._wp - asum(ji,jj) ) * r1_rdtice |
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268 | closing_net(ji,jj) = MAX( 0._wp, -divu_adv(ji,jj) ) |
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269 | opning (ji,jj) = MAX( 0._wp, divu_adv(ji,jj) ) |
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270 | ENDIF |
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271 | END DO |
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272 | END DO |
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273 | IF( lk_mpp ) CALL mpp_max( iterate_ridging ) |
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274 | |
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275 | ! Repeat if necessary. |
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276 | ! NOTE: If strength smoothing is turned on, the ridging must be |
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277 | ! iterated globally because of the boundary update in the smoothing. |
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278 | niter = niter + 1 |
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279 | ! |
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280 | IF( iterate_ridging == 1 ) THEN |
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281 | CALL rdgrft_prep |
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282 | IF( niter > nitermax ) THEN |
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283 | WRITE(numout,*) ' ALERTE : non-converging ridging scheme ' |
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284 | WRITE(numout,*) ' niter, iterate_ridging ', niter, iterate_ridging |
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285 | ENDIF |
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286 | ENDIF |
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287 | ! |
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288 | END DO !! on the do while over iter |
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289 | |
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290 | CALL ice_var_agg( 1 ) |
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291 | |
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292 | ! controls |
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293 | IF( ln_icediachk ) CALL ice_cons_hsm(1, 'icedyn_rdgrft', rdiag_v, rdiag_s, rdiag_t, rdiag_fv, rdiag_fs, rdiag_ft) ! conservation |
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294 | IF( ln_ctl ) CALL ice_prt3D ('icedyn_rdgrft') ! prints |
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295 | IF( nn_timing == 1 ) CALL timing_stop ('icedyn_rdgrft') ! timing |
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296 | ! |
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297 | END SUBROUTINE ice_dyn_rdgrft |
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298 | |
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299 | |
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300 | SUBROUTINE rdgrft_prep |
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301 | !!---------------------------------------------------------------------! |
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302 | !! *** ROUTINE rdgrft_prep *** |
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303 | !! |
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304 | !! ** Purpose : preparation for ridging and strength calculations |
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305 | !! |
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306 | !! ** Method : Compute the thickness distribution of the ice and open water |
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307 | !! participating in ridging and of the resulting ridges. |
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308 | !!---------------------------------------------------------------------! |
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309 | INTEGER :: ji, jj, jl ! dummy loop indices |
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310 | REAL(wp) :: z1_gstar, z1_astar, zhmean, zdummy ! local scalar |
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311 | REAL(wp), DIMENSION(jpi,jpj,-1:jpl) :: zGsum ! zGsum(n) = sum of areas in categories 0 to n |
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312 | !------------------------------------------------------------------------------! |
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313 | |
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314 | z1_gstar = 1._wp / rn_gstar |
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315 | z1_astar = 1._wp / rn_astar |
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316 | |
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317 | CALL ice_var_zapsmall ! Zero out categories with very small areas |
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318 | |
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319 | ! ! Ice thickness needed for rafting |
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320 | WHERE( a_i(:,:,:) >= epsi20 ) ; ht_i(:,:,:) = v_i (:,:,:) / a_i(:,:,:) |
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321 | ELSEWHERE ; ht_i(:,:,:) = 0._wp |
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322 | END WHERE |
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323 | |
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324 | !----------------------------------------------------------------- |
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325 | ! 1) Participation function: a(h) = b(h).g(h) (apartf) |
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326 | !----------------------------------------------------------------- |
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327 | ! Compute the participation function apartf; this is analogous to |
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328 | ! a(h) = b(h)g(h) as defined in Thorndike et al. (1975). |
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329 | ! area lost from category n due to ridging/closing |
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330 | ! apartf(n) = total area lost due to ridging/closing |
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331 | ! assume b(h) = (2/Gstar) * (1 - G(h)/Gstar). |
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332 | ! |
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333 | ! The expressions for apartf are found by integrating b(h)g(h) between |
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334 | ! the category boundaries. |
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335 | ! apartf is always >= 0 and SUM(apartf(0:jpl))=1 |
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336 | !----------------------------------------------------------------- |
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337 | ! |
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338 | ! Compute total area of ice plus open water. |
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339 | ! This is in general not equal to one because of divergence during transport |
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340 | asum(:,:) = ato_i(:,:) + SUM( a_i, dim=3 ) |
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341 | ! |
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342 | ! Compute cumulative thickness distribution function |
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343 | ! Compute the cumulative thickness distribution function zGsum, |
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344 | ! where zGsum(n) is the fractional area in categories 0 to n. |
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345 | ! initial value (in h = 0) equals open water area |
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346 | zGsum(:,:,-1) = 0._wp |
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347 | zGsum(:,:,0 ) = ato_i(:,:) / asum(:,:) |
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348 | DO jl = 1, jpl |
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349 | zGsum(:,:,jl) = ( ato_i(:,:) + SUM( a_i(:,:,1:jl), dim=3 ) ) / asum(:,:) ! sum(1:jl) is ok (and not jpl) |
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350 | END DO |
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351 | |
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352 | ! |
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353 | IF( ln_partf_lin ) THEN !--- Linear formulation (Thorndike et al., 1975) |
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354 | DO jl = 0, jpl |
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355 | DO jj = 1, jpj |
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356 | DO ji = 1, jpi |
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357 | IF ( zGsum(ji,jj,jl) < rn_gstar ) THEN |
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358 | apartf(ji,jj,jl) = z1_gstar * ( zGsum(ji,jj,jl) - zGsum(ji,jj,jl-1) ) * & |
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359 | & ( 2._wp - ( zGsum(ji,jj,jl-1) + zGsum(ji,jj,jl) ) * z1_gstar ) |
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360 | ELSEIF( zGsum(ji,jj,jl-1) < rn_gstar ) THEN |
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361 | apartf(ji,jj,jl) = z1_gstar * ( rn_gstar - zGsum(ji,jj,jl-1) ) * & |
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362 | & ( 2._wp - ( zGsum(ji,jj,jl-1) + rn_gstar ) * z1_gstar ) |
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363 | ELSE |
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364 | apartf(ji,jj,jl) = 0._wp |
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365 | ENDIF |
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366 | END DO |
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367 | END DO |
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368 | END DO |
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369 | ! |
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370 | ELSEIF( ln_partf_exp ) THEN !--- Exponential, more stable formulation (Lipscomb et al, 2007) |
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371 | ! |
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372 | zdummy = 1._wp / ( 1._wp - EXP(-z1_astar) ) ! precompute exponential terms using zGsum as a work array |
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373 | DO jl = -1, jpl |
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374 | zGsum(:,:,jl) = EXP( -zGsum(:,:,jl) * z1_astar ) * zdummy |
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375 | END DO |
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376 | DO jl = 0, jpl |
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377 | apartf(:,:,jl) = zGsum(:,:,jl-1) - zGsum(:,:,jl) |
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378 | END DO |
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379 | ! |
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380 | ENDIF |
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381 | |
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382 | ! !--- Ridging and rafting participation concentrations |
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383 | IF( ln_rafting .AND. ln_ridging ) THEN !- ridging & rafting |
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384 | DO jl = 1, jpl |
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385 | DO jj = 1, jpj |
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386 | DO ji = 1, jpi |
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387 | aridge(ji,jj,jl) = ( 1._wp + TANH ( rn_craft * ( ht_i(ji,jj,jl) - rn_hraft ) ) ) * 0.5_wp * apartf(ji,jj,jl) |
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388 | araft (ji,jj,jl) = apartf(ji,jj,jl) - aridge(ji,jj,jl) |
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389 | END DO |
---|
390 | END DO |
---|
391 | END DO |
---|
392 | ELSEIF( ln_ridging .AND. .NOT. ln_rafting ) THEN !- ridging alone |
---|
393 | aridge(:,:,:) = apartf(:,:,1:jpl) |
---|
394 | araft (:,:,:) = 0._wp |
---|
395 | ELSEIF( ln_rafting .AND. .NOT. ln_ridging ) THEN !- rafting alone |
---|
396 | aridge(:,:,:) = 0._wp |
---|
397 | araft (:,:,:) = apartf(:,:,1:jpl) |
---|
398 | ELSE !- no ridging & no rafting |
---|
399 | aridge(:,:,:) = 0._wp |
---|
400 | araft (:,:,:) = 0._wp |
---|
401 | ENDIF |
---|
402 | |
---|
403 | !----------------------------------------------------------------- |
---|
404 | ! 2) Transfer function |
---|
405 | !----------------------------------------------------------------- |
---|
406 | ! Compute max and min ridged ice thickness for each ridging category. |
---|
407 | ! Assume ridged ice is uniformly distributed between hrmin and hrmax. |
---|
408 | ! |
---|
409 | ! This parameterization is a modified version of Hibler (1980). |
---|
410 | ! The mean ridging thickness, zhmean, is proportional to hi^(0.5) |
---|
411 | ! and for very thick ridging ice must be >= hrdg_hi_min*hi |
---|
412 | ! |
---|
413 | ! The minimum ridging thickness, hrmin, is equal to 2*hi |
---|
414 | ! (i.e., rafting) and for very thick ridging ice is |
---|
415 | ! constrained by hrmin <= (zhmean + hi)/2. |
---|
416 | ! |
---|
417 | ! The maximum ridging thickness, hrmax, is determined by |
---|
418 | ! zhmean and hrmin. |
---|
419 | ! |
---|
420 | ! These modifications have the effect of reducing the ice strength |
---|
421 | ! (relative to the Hibler formulation) when very thick ice is |
---|
422 | ! ridging. |
---|
423 | ! |
---|
424 | ! aksum = net area removed/ total area removed |
---|
425 | ! where total area removed = area of ice that ridges |
---|
426 | ! net area removed = total area removed - area of new ridges |
---|
427 | !----------------------------------------------------------------- |
---|
428 | |
---|
429 | aksum(:,:) = apartf(:,:,0) |
---|
430 | zdummy = 1._wp / hi_hrft |
---|
431 | ! Transfer function |
---|
432 | DO jl = 1, jpl !all categories have a specific transfer function |
---|
433 | DO jj = 1, jpj |
---|
434 | DO ji = 1, jpi |
---|
435 | IF ( apartf(ji,jj,jl) > 0._wp ) THEN |
---|
436 | zhmean = MAX( SQRT( rn_hstar * ht_i(ji,jj,jl) ), ht_i(ji,jj,jl) * hrdg_hi_min ) |
---|
437 | hrmin (ji,jj,jl) = MIN( 2._wp * ht_i(ji,jj,jl), 0.5_wp * ( zhmean + ht_i(ji,jj,jl) ) ) |
---|
438 | hrmax (ji,jj,jl) = 2._wp * zhmean - hrmin(ji,jj,jl) |
---|
439 | hraft (ji,jj,jl) = ht_i(ji,jj,jl) * zdummy |
---|
440 | hi_hrdg(ji,jj,jl) = ht_i(ji,jj,jl) / MAX( zhmean, epsi20 ) |
---|
441 | ! |
---|
442 | ! Normalization factor : aksum, ensures mass conservation |
---|
443 | aksum(ji,jj) = aksum(ji,jj) + aridge(ji,jj,jl) * ( 1._wp - hi_hrdg(ji,jj,jl) ) & |
---|
444 | & + araft (ji,jj,jl) * ( 1._wp - hi_hrft ) |
---|
445 | ELSE |
---|
446 | hrmin (ji,jj,jl) = 0._wp |
---|
447 | hrmax (ji,jj,jl) = 0._wp |
---|
448 | hraft (ji,jj,jl) = 0._wp |
---|
449 | hi_hrdg(ji,jj,jl) = 1._wp |
---|
450 | ENDIF |
---|
451 | END DO |
---|
452 | END DO |
---|
453 | END DO |
---|
454 | ! |
---|
455 | END SUBROUTINE rdgrft_prep |
---|
456 | |
---|
457 | |
---|
458 | SUBROUTINE rdgrft_shift( opning, closing_gross ) |
---|
459 | !!---------------------------------------------------------------------- |
---|
460 | !! *** ROUTINE rdgrft_shift *** |
---|
461 | !! |
---|
462 | !! ** Purpose : shift ridging ice among thickness categories of ice thickness |
---|
463 | !! |
---|
464 | !! ** Method : Remove area, volume, and energy from each ridging category |
---|
465 | !! and add to thicker ice categories. |
---|
466 | !!---------------------------------------------------------------------- |
---|
467 | REAL(wp), DIMENSION(jpi,jpj), INTENT(in) :: opning ! rate of opening due to divergence/shear |
---|
468 | REAL(wp), DIMENSION(jpi,jpj), INTENT(in) :: closing_gross ! rate at which area retreats, excluding area of new ridges |
---|
469 | ! |
---|
470 | INTEGER :: ji, jj, jl, jl1, jl2, jk ! dummy loop indices |
---|
471 | INTEGER :: ij ! horizontal index, combines i and j loops |
---|
472 | INTEGER :: icells ! number of cells with a_i > puny |
---|
473 | REAL(wp) :: hL, hR, farea ! left and right limits of integration and new area going to jl2 |
---|
474 | |
---|
475 | INTEGER , DIMENSION(jpij) :: indxi, indxj ! compressed indices |
---|
476 | REAL(wp), DIMENSION(jpij) :: zswitch, fvol ! new ridge volume going to jl2 |
---|
477 | |
---|
478 | REAL(wp), DIMENSION(jpij) :: afrac ! fraction of category area ridged |
---|
479 | REAL(wp), DIMENSION(jpij) :: ardg1 , ardg2 ! area of ice ridged & new ridges |
---|
480 | REAL(wp), DIMENSION(jpij) :: vsrdg , esrdg ! snow volume & energy of ridging ice |
---|
481 | ! MV MP 2016 |
---|
482 | REAL(wp), DIMENSION(jpij) :: vprdg ! pond volume of ridging ice |
---|
483 | REAL(wp), DIMENSION(jpij) :: aprdg1 ! pond area of ridging ice |
---|
484 | REAL(wp), DIMENSION(jpij) :: aprdg2 ! pond area of ridging ice |
---|
485 | ! END MV MP 2016 |
---|
486 | REAL(wp), DIMENSION(jpij) :: dhr, dhr2 ! hrmax - hrmin & hrmax^2 - hrmin^2 |
---|
487 | |
---|
488 | REAL(wp), DIMENSION(jpij) :: vrdg1 ! volume of ice ridged |
---|
489 | REAL(wp), DIMENSION(jpij) :: vrdg2 ! volume of new ridges |
---|
490 | REAL(wp), DIMENSION(jpij) :: vsw ! volume of seawater trapped into ridges |
---|
491 | REAL(wp), DIMENSION(jpij) :: srdg1 ! sal*volume of ice ridged |
---|
492 | REAL(wp), DIMENSION(jpij) :: srdg2 ! sal*volume of new ridges |
---|
493 | REAL(wp), DIMENSION(jpij) :: smsw ! sal*volume of water trapped into ridges |
---|
494 | REAL(wp), DIMENSION(jpij) :: oirdg1, oirdg2 ! ice age of ice ridged |
---|
495 | |
---|
496 | REAL(wp), DIMENSION(jpij) :: afrft ! fraction of category area rafted |
---|
497 | REAL(wp), DIMENSION(jpij) :: arft1 , arft2 ! area of ice rafted and new rafted zone |
---|
498 | REAL(wp), DIMENSION(jpij) :: virft , vsrft ! ice & snow volume of rafting ice |
---|
499 | ! MV MP 2016 |
---|
500 | REAL(wp), DIMENSION(jpij) :: vprft ! pond volume of rafting ice |
---|
501 | REAL(wp), DIMENSION(jpij) :: aprft1 ! pond area of rafted ice |
---|
502 | REAL(wp), DIMENSION(jpij) :: aprft2 ! pond area of new rafted ice |
---|
503 | ! END MV MP 2016 |
---|
504 | REAL(wp), DIMENSION(jpij) :: esrft , smrft ! snow energy & salinity of rafting ice |
---|
505 | REAL(wp), DIMENSION(jpij) :: oirft1, oirft2 ! ice age of ice rafted |
---|
506 | |
---|
507 | REAL(wp), DIMENSION(jpij,nlay_i) :: eirft ! ice energy of rafting ice |
---|
508 | REAL(wp), DIMENSION(jpij,nlay_i) :: erdg1 ! enth*volume of ice ridged |
---|
509 | REAL(wp), DIMENSION(jpij,nlay_i) :: erdg2 ! enth*volume of new ridges |
---|
510 | REAL(wp), DIMENSION(jpij,nlay_i) :: ersw ! enth of water trapped into ridges |
---|
511 | !!---------------------------------------------------------------------- |
---|
512 | |
---|
513 | !------------------------------------------------------------------------------- |
---|
514 | ! 1) Compute change in open water area due to closing and opening. |
---|
515 | !------------------------------------------------------------------------------- |
---|
516 | DO jj = 1, jpj |
---|
517 | DO ji = 1, jpi |
---|
518 | ato_i(ji,jj) = MAX( 0._wp, ato_i(ji,jj) + & |
---|
519 | & ( opning(ji,jj) - apartf(ji,jj,0) * closing_gross(ji,jj) ) * rdt_ice ) |
---|
520 | END DO |
---|
521 | END DO |
---|
522 | |
---|
523 | !----------------------------------------------------------------- |
---|
524 | ! 2) Pump everything from ice which is being ridged / rafted |
---|
525 | !----------------------------------------------------------------- |
---|
526 | ! Compute the area, volume, and energy of ice ridging in each |
---|
527 | ! category, along with the area of the resulting ridge. |
---|
528 | |
---|
529 | DO jl1 = 1, jpl !jl1 describes the ridging category |
---|
530 | |
---|
531 | !------------------------------------------------ |
---|
532 | ! 2.1) Identify grid cells with nonzero ridging |
---|
533 | !------------------------------------------------ |
---|
534 | icells = 0 |
---|
535 | DO jj = 1, jpj |
---|
536 | DO ji = 1, jpi |
---|
537 | IF( apartf(ji,jj,jl1) > 0._wp .AND. closing_gross(ji,jj) > 0._wp ) THEN |
---|
538 | icells = icells + 1 |
---|
539 | indxi(icells) = ji |
---|
540 | indxj(icells) = jj |
---|
541 | ENDIF |
---|
542 | END DO |
---|
543 | END DO |
---|
544 | |
---|
545 | DO ij = 1, icells |
---|
546 | ji = indxi(ij) ; jj = indxj(ij) |
---|
547 | |
---|
548 | !-------------------------------------------------------------------- |
---|
549 | ! 2.2) Compute area of ridging ice (ardg1) and of new ridge (ardg2) |
---|
550 | !-------------------------------------------------------------------- |
---|
551 | ardg1(ij) = aridge(ji,jj,jl1) * closing_gross(ji,jj) * rdt_ice |
---|
552 | arft1(ij) = araft (ji,jj,jl1) * closing_gross(ji,jj) * rdt_ice |
---|
553 | |
---|
554 | !--------------------------------------------------------------- |
---|
555 | ! 2.3) Compute ridging /rafting fractions, make sure afrac <=1 |
---|
556 | !--------------------------------------------------------------- |
---|
557 | afrac(ij) = ardg1(ij) / a_i(ji,jj,jl1) !ridging |
---|
558 | afrft(ij) = arft1(ij) / a_i(ji,jj,jl1) !rafting |
---|
559 | ardg2(ij) = ardg1(ij) * hi_hrdg(ji,jj,jl1) |
---|
560 | arft2(ij) = arft1(ij) * hi_hrft |
---|
561 | |
---|
562 | !-------------------------------------------------------------------------- |
---|
563 | ! 2.4) Substract area, volume, and energy from ridging |
---|
564 | ! / rafting category n1. |
---|
565 | !-------------------------------------------------------------------------- |
---|
566 | vrdg1(ij) = v_i(ji,jj,jl1) * afrac(ij) |
---|
567 | vrdg2(ij) = vrdg1(ij) * ( 1. + rn_porordg ) |
---|
568 | vsw (ij) = vrdg1(ij) * rn_porordg |
---|
569 | |
---|
570 | vsrdg (ij) = v_s (ji,jj, jl1) * afrac(ij) |
---|
571 | esrdg (ij) = e_s (ji,jj,1,jl1) * afrac(ij) |
---|
572 | !MV MP 2016 |
---|
573 | IF ( nn_pnd_scheme > 0 ) THEN |
---|
574 | aprdg1(ij) = a_ip(ji,jj, jl1) * afrac(ij) |
---|
575 | aprdg2(ij) = a_ip(ji,jj, jl1) * afrac(ij) * hi_hrdg(ji,jj,jl1) |
---|
576 | vprdg(ij) = v_ip(ji,jj, jl1) * afrac(ij) |
---|
577 | ENDIF |
---|
578 | ! END MV MP 2016 |
---|
579 | srdg1 (ij) = smv_i(ji,jj, jl1) * afrac(ij) |
---|
580 | oirdg1(ij) = oa_i (ji,jj, jl1) * afrac(ij) |
---|
581 | oirdg2(ij) = oa_i (ji,jj, jl1) * afrac(ij) * hi_hrdg(ji,jj,jl1) |
---|
582 | |
---|
583 | ! rafting volumes, heat contents ... |
---|
584 | virft (ij) = v_i (ji,jj, jl1) * afrft(ij) |
---|
585 | vsrft (ij) = v_s (ji,jj, jl1) * afrft(ij) |
---|
586 | !MV MP 2016 |
---|
587 | IF ( nn_pnd_scheme > 0 ) THEN |
---|
588 | aprft1(ij) = a_ip (ji,jj, jl1) * afrft(ij) |
---|
589 | aprft2(ij) = a_ip (ji,jj, jl1) * afrft(ij) * hi_hrft |
---|
590 | vprft(ij) = v_ip(ji,jj,jl1) * afrft(ij) |
---|
591 | ENDIF |
---|
592 | ! END MV MP 2016 |
---|
593 | srdg1 (ij) = smv_i(ji,jj, jl1) * afrac(ij) |
---|
594 | esrft (ij) = e_s (ji,jj,1,jl1) * afrft(ij) |
---|
595 | smrft (ij) = smv_i(ji,jj, jl1) * afrft(ij) |
---|
596 | oirft1(ij) = oa_i (ji,jj, jl1) * afrft(ij) |
---|
597 | oirft2(ij) = oa_i (ji,jj, jl1) * afrft(ij) * hi_hrft |
---|
598 | |
---|
599 | !----------------------------------------------------------------- |
---|
600 | ! 2.5) Compute properties of new ridges |
---|
601 | !----------------------------------------------------------------- |
---|
602 | smsw(ij) = vsw(ij) * sss_m(ji,jj) ! salt content of seawater frozen in voids |
---|
603 | srdg2(ij) = srdg1(ij) + smsw(ij) ! salt content of new ridge |
---|
604 | |
---|
605 | sfx_dyn(ji,jj) = sfx_dyn(ji,jj) - smsw(ij) * rhoic * r1_rdtice |
---|
606 | wfx_dyn(ji,jj) = wfx_dyn(ji,jj) - vsw (ij) * rhoic * r1_rdtice ! increase in ice volume due to seawater frozen in voids |
---|
607 | |
---|
608 | ! virtual salt flux to keep salinity constant |
---|
609 | IF( nn_icesal == 1 .OR. nn_icesal == 3 ) THEN |
---|
610 | srdg2(ij) = srdg2(ij) - vsw(ij) * ( sss_m(ji,jj) - sm_i(ji,jj,jl1) ) ! ridge salinity = sm_i |
---|
611 | sfx_bri(ji,jj) = sfx_bri(ji,jj) + sss_m(ji,jj) * vsw(ij) * rhoic * r1_rdtice & ! put back sss_m into the ocean |
---|
612 | & - sm_i(ji,jj,jl1) * vsw(ij) * rhoic * r1_rdtice ! and get sm_i from the ocean |
---|
613 | ENDIF |
---|
614 | |
---|
615 | !------------------------------------------ |
---|
616 | ! 2.6 Put the snow somewhere in the ocean |
---|
617 | !------------------------------------------ |
---|
618 | ! Place part of the snow lost by ridging into the ocean. |
---|
619 | ! Note that esrdg > 0; the ocean must cool to melt snow. |
---|
620 | ! If the ocean temp = Tf already, new ice must grow. |
---|
621 | ! During the next time step, thermo_rates will determine whether |
---|
622 | ! the ocean cools or new ice grows. |
---|
623 | wfx_snw_dyn(ji,jj) = wfx_snw_dyn(ji,jj) + ( rhosn * vsrdg(ij) * ( 1._wp - rn_fsnwrdg ) & |
---|
624 | & + rhosn * vsrft(ij) * ( 1._wp - rn_fsnwrft ) ) * r1_rdtice ! fresh water source for ocean |
---|
625 | |
---|
626 | hfx_dyn(ji,jj) = hfx_dyn(ji,jj) + ( - esrdg(ij) * ( 1._wp - rn_fsnwrdg ) & |
---|
627 | & - esrft(ij) * ( 1._wp - rn_fsnwrft ) ) * r1_rdtice ! heat sink for ocean (<0, W.m-2) |
---|
628 | |
---|
629 | ! MV MP 2016 |
---|
630 | !------------------------------------------ |
---|
631 | ! 2.7 Put the melt pond water in the ocean |
---|
632 | !------------------------------------------ |
---|
633 | ! Place part of the melt pond volume into the ocean. |
---|
634 | IF ( ( nn_pnd_scheme > 0 ) .AND. ln_pnd_fw ) THEN |
---|
635 | wfx_pnd(ji,jj) = wfx_pnd(ji,jj) + ( rhofw * vprdg(ij) * ( 1._wp - rn_fpndrdg ) & |
---|
636 | & + rhofw * vprft(ij) * ( 1._wp - rn_fpndrft ) ) * r1_rdtice ! fresh water source for ocean |
---|
637 | ENDIF |
---|
638 | ! END MV MP 2016 |
---|
639 | |
---|
640 | !----------------------------------------------------------------- |
---|
641 | ! 2.8 Compute quantities used to apportion ice among categories |
---|
642 | ! in the n2 loop below |
---|
643 | !----------------------------------------------------------------- |
---|
644 | dhr (ij) = 1._wp / ( hrmax(ji,jj,jl1) - hrmin(ji,jj,jl1) ) |
---|
645 | dhr2(ij) = 1._wp / ( hrmax(ji,jj,jl1) * hrmax(ji,jj,jl1) - hrmin(ji,jj,jl1) * hrmin(ji,jj,jl1) ) |
---|
646 | |
---|
647 | |
---|
648 | ! update jl1 (removing ridged/rafted area) |
---|
649 | a_i (ji,jj, jl1) = a_i (ji,jj, jl1) - ardg1 (ij) - arft1 (ij) |
---|
650 | v_i (ji,jj, jl1) = v_i (ji,jj, jl1) - vrdg1 (ij) - virft (ij) |
---|
651 | v_s (ji,jj, jl1) = v_s (ji,jj, jl1) - vsrdg (ij) - vsrft (ij) |
---|
652 | e_s (ji,jj,1,jl1) = e_s (ji,jj,1,jl1) - esrdg (ij) - esrft (ij) |
---|
653 | smv_i(ji,jj, jl1) = smv_i(ji,jj, jl1) - srdg1 (ij) - smrft (ij) |
---|
654 | oa_i (ji,jj, jl1) = oa_i (ji,jj, jl1) - oirdg1(ij) - oirft1(ij) |
---|
655 | |
---|
656 | ! MV MP 2016 |
---|
657 | IF ( nn_pnd_scheme > 0 ) THEN |
---|
658 | v_ip (ji,jj,jl1) = v_ip (ji,jj,jl1) - vprdg (ij) - vprft (ij) |
---|
659 | a_ip (ji,jj,jl1) = a_ip (ji,jj,jl1) - aprdg1(ij) - aprft1(ij) |
---|
660 | ENDIF |
---|
661 | ! END MV MP 2016 |
---|
662 | |
---|
663 | END DO |
---|
664 | |
---|
665 | !-------------------------------------------------------------------- |
---|
666 | ! 2.9 Compute ridging ice enthalpy, remove it from ridging ice and |
---|
667 | ! compute ridged ice enthalpy |
---|
668 | !-------------------------------------------------------------------- |
---|
669 | DO jk = 1, nlay_i |
---|
670 | DO ij = 1, icells |
---|
671 | ji = indxi(ij) ; jj = indxj(ij) |
---|
672 | ! heat content of ridged ice |
---|
673 | erdg1(ij,jk) = e_i(ji,jj,jk,jl1) * afrac(ij) |
---|
674 | eirft(ij,jk) = e_i(ji,jj,jk,jl1) * afrft(ij) |
---|
675 | |
---|
676 | ! enthalpy of the trapped seawater (J/m2, >0) |
---|
677 | ! clem: if sst>0, then ersw <0 (is that possible?) |
---|
678 | ersw(ij,jk) = - rhoic * vsw(ij) * rcp * sst_m(ji,jj) * r1_nlay_i |
---|
679 | |
---|
680 | ! heat flux to the ocean |
---|
681 | hfx_dyn(ji,jj) = hfx_dyn(ji,jj) + ersw(ij,jk) * r1_rdtice ! > 0 [W.m-2] ocean->ice flux |
---|
682 | |
---|
683 | ! it is added to sea ice because the sign convention is the opposite of the sign convention for the ocean |
---|
684 | erdg2(ij,jk) = erdg1(ij,jk) + ersw(ij,jk) |
---|
685 | |
---|
686 | ! update jl1 |
---|
687 | e_i(ji,jj,jk,jl1) = e_i(ji,jj,jk,jl1) - erdg1(ij,jk) - eirft(ij,jk) |
---|
688 | |
---|
689 | END DO |
---|
690 | END DO |
---|
691 | |
---|
692 | !------------------------------------------------------------------------------- |
---|
693 | ! 3) Add area, volume, and energy of new ridge to each category jl2 |
---|
694 | !------------------------------------------------------------------------------- |
---|
695 | DO jl2 = 1, jpl |
---|
696 | ! over categories to which ridged/rafted ice is transferred |
---|
697 | DO ij = 1, icells |
---|
698 | ji = indxi(ij) ; jj = indxj(ij) |
---|
699 | |
---|
700 | ! Compute the fraction of ridged ice area and volume going to thickness category jl2. |
---|
701 | IF( hrmin(ji,jj,jl1) <= hi_max(jl2) .AND. hrmax(ji,jj,jl1) > hi_max(jl2-1) ) THEN |
---|
702 | hL = MAX( hrmin(ji,jj,jl1), hi_max(jl2-1) ) |
---|
703 | hR = MIN( hrmax(ji,jj,jl1), hi_max(jl2) ) |
---|
704 | farea = ( hR - hL ) * dhr(ij) |
---|
705 | fvol(ij) = ( hR * hR - hL * hL ) * dhr2(ij) |
---|
706 | ELSE |
---|
707 | farea = 0._wp |
---|
708 | fvol(ij) = 0._wp |
---|
709 | ENDIF |
---|
710 | |
---|
711 | ! Compute the fraction of rafted ice area and volume going to thickness category jl2 |
---|
712 | !!gm see above IF( hraft(ji,jj,jl1) <= hi_max(jl2) .AND. hraft(ji,jj,jl1) > hi_max(jl2-1) ) THEN |
---|
713 | IF( hi_max(jl2-1) < hraft(ji,jj,jl1) .AND. hraft(ji,jj,jl1) <= hi_max(jl2) ) THEN ; zswitch(ij) = 1._wp |
---|
714 | ELSE ; zswitch(ij) = 0._wp |
---|
715 | ENDIF |
---|
716 | ! |
---|
717 | a_i (ji,jj ,jl2) = a_i (ji,jj ,jl2) + ( ardg2 (ij) * farea + arft2 (ij) * zswitch(ij) ) |
---|
718 | oa_i (ji,jj ,jl2) = oa_i (ji,jj ,jl2) + ( oirdg2(ij) * farea + oirft2(ij) * zswitch(ij) ) |
---|
719 | v_i (ji,jj ,jl2) = v_i (ji,jj ,jl2) + ( vrdg2 (ij) * fvol(ij) + virft (ij) * zswitch(ij) ) |
---|
720 | smv_i(ji,jj ,jl2) = smv_i(ji,jj ,jl2) + ( srdg2 (ij) * fvol(ij) + smrft (ij) * zswitch(ij) ) |
---|
721 | v_s (ji,jj ,jl2) = v_s (ji,jj ,jl2) + ( vsrdg (ij) * rn_fsnwrdg * fvol(ij) + & |
---|
722 | & vsrft (ij) * rn_fsnwrft * zswitch(ij) ) |
---|
723 | e_s (ji,jj,1,jl2) = e_s (ji,jj,1,jl2) + ( esrdg (ij) * rn_fsnwrdg * fvol(ij) + & |
---|
724 | & esrft (ij) * rn_fsnwrft * zswitch(ij) ) |
---|
725 | ! MV MP 2016 |
---|
726 | IF ( nn_pnd_scheme > 0 ) THEN |
---|
727 | v_ip (ji,jj,jl2) = v_ip(ji,jj,jl2) + ( vprdg (ij) * rn_fpndrdg * fvol (ij) & |
---|
728 | & + vprft (ij) * rn_fpndrft * zswitch(ij) ) |
---|
729 | a_ip (ji,jj,jl2) = a_ip(ji,jj,jl2) + ( aprdg2(ij) * rn_fpndrdg * farea & |
---|
730 | & + aprft2(ij) * rn_fpndrft * zswitch(ji) ) |
---|
731 | ENDIF |
---|
732 | ! END MV MP 2016 |
---|
733 | END DO |
---|
734 | |
---|
735 | ! Transfer ice energy to category jl2 by ridging |
---|
736 | DO jk = 1, nlay_i |
---|
737 | DO ij = 1, icells |
---|
738 | ji = indxi(ij) ; jj = indxj(ij) |
---|
739 | e_i(ji,jj,jk,jl2) = e_i(ji,jj,jk,jl2) + erdg2(ij,jk) * fvol(ij) + eirft(ij,jk) * zswitch(ij) |
---|
740 | END DO |
---|
741 | END DO |
---|
742 | ! |
---|
743 | END DO ! jl2 |
---|
744 | ! |
---|
745 | END DO ! jl1 (deforming categories) |
---|
746 | ! |
---|
747 | END SUBROUTINE rdgrft_shift |
---|
748 | |
---|
749 | |
---|
750 | SUBROUTINE ice_strength |
---|
751 | !!---------------------------------------------------------------------- |
---|
752 | !! *** ROUTINE ice_strength *** |
---|
753 | !! |
---|
754 | !! ** Purpose : computes ice strength used in dynamics routines of ice thickness |
---|
755 | !! |
---|
756 | !! ** Method : Compute the strength of the ice pack, defined as the energy (J m-2) |
---|
757 | !! dissipated per unit area removed from the ice pack under compression, |
---|
758 | !! and assumed proportional to the change in potential energy caused |
---|
759 | !! by ridging. Note that only Hibler's formulation is stable and that |
---|
760 | !! ice strength has to be smoothed |
---|
761 | !!---------------------------------------------------------------------- |
---|
762 | INTEGER :: ji,jj, jl ! dummy loop indices |
---|
763 | INTEGER :: ismooth ! smoothing the resistance to deformation |
---|
764 | INTEGER :: itframe ! number of time steps for the P smoothing |
---|
765 | REAL(wp) :: zp, z1_3 ! local scalars |
---|
766 | REAL(wp), DIMENSION(jpi,jpj) :: zworka ! temporary array used here |
---|
767 | REAL(wp), DIMENSION(jpi,jpj) :: zstrp1, zstrp2 ! strength at previous time steps |
---|
768 | !!---------------------------------------------------------------------- |
---|
769 | |
---|
770 | ! !--------------------------------------------------! |
---|
771 | CALL rdgrft_prep ! Thickness distribution of ridging and ridged ice ! |
---|
772 | ! !--------------------------------------------------! |
---|
773 | |
---|
774 | ! !--------------------------------------------------! |
---|
775 | IF( ln_str_R75 ) THEN ! Ice strength => Rothrock (1975) method ! |
---|
776 | ! !--------------------------------------------------! |
---|
777 | z1_3 = 1._wp / 3._wp |
---|
778 | DO jl = 1, jpl |
---|
779 | WHERE( apartf(:,:,jl) > 0._wp ) |
---|
780 | strength(:,:) = - apartf(:,:,jl) * ht_i (:,:,jl) * ht_i(:,:,jl) & ! PE loss from deforming ice |
---|
781 | & + 2._wp * araft (:,:,jl) * ht_i (:,:,jl) * ht_i(:,:,jl) & ! PE gain from rafting ice |
---|
782 | & + aridge(:,:,jl) * hi_hrdg(:,:,jl) * z1_3 * & ! PE gain from ridging ice |
---|
783 | & ( hrmax(:,:,jl) * hrmax (:,:,jl) + & |
---|
784 | & hrmin(:,:,jl) * hrmin (:,:,jl) + & |
---|
785 | & hrmax(:,:,jl) * hrmin (:,:,jl) ) |
---|
786 | ELSEWHERE |
---|
787 | strength(:,:) = 0._wp |
---|
788 | END WHERE |
---|
789 | END DO |
---|
790 | strength(:,:) = rn_perdg * zdrho * strength(:,:) / aksum(:,:) * tmask(:,:,1) |
---|
791 | ! where zdrho = (g/2)*(rhow-rhoi)*(rhoi/rhow) and rn_perdg accounts for frictional dissipation |
---|
792 | ismooth = 1 |
---|
793 | ! !--------------------------------------------------! |
---|
794 | ELSEIF( ln_str_H79 ) THEN ! Ice strength => Hibler (1979) method ! |
---|
795 | ! !--------------------------------------------------! |
---|
796 | strength(:,:) = rn_pstar * SUM( v_i(:,:,:), dim=3 ) * EXP( -rn_crhg * ( 1._wp - SUM( a_i(:,:,:), dim=3 ) ) ) |
---|
797 | ! |
---|
798 | ismooth = 1 |
---|
799 | ! |
---|
800 | ENDIF |
---|
801 | ! !--------------------------------------------------! |
---|
802 | SELECT CASE( ismooth ) ! Smoothing ice strength ! |
---|
803 | ! !--------------------------------------------------! |
---|
804 | CASE( 1 ) !--- Spatial smoothing |
---|
805 | DO jj = 2, jpjm1 |
---|
806 | DO ji = 2, jpim1 |
---|
807 | IF ( ( asum(ji,jj) - ato_i(ji,jj) ) > 0._wp ) THEN |
---|
808 | zworka(ji,jj) = ( 4.0 * strength(ji,jj) & |
---|
809 | & + strength(ji-1,jj) * tmask(ji-1,jj,1) + strength(ji+1,jj) * tmask(ji+1,jj,1) & |
---|
810 | & + strength(ji,jj-1) * tmask(ji,jj-1,1) + strength(ji,jj+1) * tmask(ji,jj+1,1) & |
---|
811 | & ) / ( 4.0 + tmask(ji-1,jj,1) + tmask(ji+1,jj,1) + tmask(ji,jj-1,1) + tmask(ji,jj+1,1) ) |
---|
812 | ELSE |
---|
813 | zworka(ji,jj) = 0._wp |
---|
814 | ENDIF |
---|
815 | END DO |
---|
816 | END DO |
---|
817 | |
---|
818 | DO jj = 2, jpjm1 |
---|
819 | DO ji = 2, jpim1 |
---|
820 | strength(ji,jj) = zworka(ji,jj) |
---|
821 | END DO |
---|
822 | END DO |
---|
823 | CALL lbc_lnk( strength, 'T', 1. ) |
---|
824 | ! |
---|
825 | CASE( 2 ) !--- Temporal smoothing |
---|
826 | IF ( kt_ice == nit000 ) THEN |
---|
827 | zstrp1(:,:) = 0._wp |
---|
828 | zstrp2(:,:) = 0._wp |
---|
829 | ENDIF |
---|
830 | ! |
---|
831 | DO jj = 2, jpjm1 |
---|
832 | DO ji = 2, jpim1 |
---|
833 | IF ( ( asum(ji,jj) - ato_i(ji,jj) ) > 0._wp ) THEN |
---|
834 | itframe = 1 ! number of time steps for the running mean |
---|
835 | IF ( zstrp1(ji,jj) > 0._wp ) itframe = itframe + 1 |
---|
836 | IF ( zstrp2(ji,jj) > 0._wp ) itframe = itframe + 1 |
---|
837 | zp = ( strength(ji,jj) + zstrp1(ji,jj) + zstrp2(ji,jj) ) / itframe |
---|
838 | zstrp2 (ji,jj) = zstrp1 (ji,jj) |
---|
839 | zstrp1 (ji,jj) = strength(ji,jj) |
---|
840 | strength(ji,jj) = zp |
---|
841 | ENDIF |
---|
842 | END DO |
---|
843 | END DO |
---|
844 | CALL lbc_lnk( strength, 'T', 1. ) |
---|
845 | ! |
---|
846 | END SELECT |
---|
847 | ! |
---|
848 | END SUBROUTINE ice_strength |
---|
849 | |
---|
850 | |
---|
851 | SUBROUTINE ice_dyn_rdgrft_init |
---|
852 | !!------------------------------------------------------------------- |
---|
853 | !! *** ROUTINE ice_dyn_rdgrft_init *** |
---|
854 | !! |
---|
855 | !! ** Purpose : Physical constants and parameters linked |
---|
856 | !! to the mechanical ice redistribution |
---|
857 | !! |
---|
858 | !! ** Method : Read the namdyn_rdgrft namelist |
---|
859 | !! and check the parameters values |
---|
860 | !! called at the first timestep (nit000) |
---|
861 | !! |
---|
862 | !! ** input : Namelist namdyn_rdgrft |
---|
863 | !!------------------------------------------------------------------- |
---|
864 | INTEGER :: ios ! Local integer output status for namelist read |
---|
865 | !! |
---|
866 | NAMELIST/namdyn_rdgrft/ ln_str_H79, rn_pstar, rn_crhg, & |
---|
867 | & ln_str_R75, rn_perdg, & |
---|
868 | & rn_csrdg , & |
---|
869 | & ln_partf_lin, rn_gstar, & |
---|
870 | & ln_partf_exp, rn_astar, & |
---|
871 | & ln_ridging, rn_hstar, rn_porordg, rn_fsnwrdg, rn_fpndrdg, & |
---|
872 | & ln_rafting, rn_hraft, rn_craft , rn_fsnwrft, rn_fpndrft |
---|
873 | !!------------------------------------------------------------------- |
---|
874 | ! |
---|
875 | REWIND( numnam_ice_ref ) ! Namelist namicetdme in reference namelist : Ice mechanical ice redistribution |
---|
876 | READ ( numnam_ice_ref, namdyn_rdgrft, IOSTAT = ios, ERR = 901) |
---|
877 | 901 IF( ios /= 0 ) CALL ctl_nam ( ios , 'namdyn_rdgrft in reference namelist', lwp ) |
---|
878 | ! |
---|
879 | REWIND( numnam_ice_cfg ) ! Namelist namdyn_rdgrft in configuration namelist : Ice mechanical ice redistribution |
---|
880 | READ ( numnam_ice_cfg, namdyn_rdgrft, IOSTAT = ios, ERR = 902 ) |
---|
881 | 902 IF( ios /= 0 ) CALL ctl_nam ( ios , 'namdyn_rdgrft in configuration namelist', lwp ) |
---|
882 | IF(lwm) WRITE ( numoni, namdyn_rdgrft ) |
---|
883 | ! |
---|
884 | IF (lwp) THEN ! control print |
---|
885 | WRITE(numout,*) |
---|
886 | WRITE(numout,*) 'ice_dyn_rdgrft_init: ice parameters for ridging/rafting ' |
---|
887 | WRITE(numout,*) '~~~~~~~~~~~~~~~~~~' |
---|
888 | WRITE(numout,*) ' Namelist namdyn_rdgrft:' |
---|
889 | WRITE(numout,*) ' ice strength parameterization Hibler (1979) ln_str_H79 = ', ln_str_H79 |
---|
890 | WRITE(numout,*) ' 1st bulk-rheology parameter rn_pstar = ', rn_pstar |
---|
891 | WRITE(numout,*) ' 2nd bulk-rhelogy parameter rn_crhg = ', rn_crhg |
---|
892 | WRITE(numout,*) ' ice strength parameterization Rothrock (1975) ln_str_R75 = ', ln_str_R75 |
---|
893 | WRITE(numout,*) ' Ratio of ridging work to PotEner change in ridging rn_perdg = ', rn_perdg |
---|
894 | WRITE(numout,*) ' Fraction of shear energy contributing to ridging rn_csrdg = ', rn_csrdg |
---|
895 | WRITE(numout,*) ' linear ridging participation function ln_partf_lin = ', ln_partf_lin |
---|
896 | WRITE(numout,*) ' Fraction of ice coverage contributing to ridging rn_gstar = ', rn_gstar |
---|
897 | WRITE(numout,*) ' Exponential ridging participation function ln_partf_exp = ', ln_partf_exp |
---|
898 | WRITE(numout,*) ' Equivalent to G* for an exponential function rn_astar = ', rn_astar |
---|
899 | WRITE(numout,*) ' Ridging of ice sheets or not ln_ridging = ', ln_ridging |
---|
900 | WRITE(numout,*) ' max ridged ice thickness rn_hstar = ', rn_hstar |
---|
901 | WRITE(numout,*) ' Initial porosity of ridges rn_porordg = ', rn_porordg |
---|
902 | WRITE(numout,*) ' Fraction of snow volume conserved during ridging rn_fsnwrdg = ', rn_fsnwrdg |
---|
903 | WRITE(numout,*) ' Fraction of pond volume conserved during ridging rn_fpndrdg = ', rn_fpndrdg |
---|
904 | WRITE(numout,*) ' Rafting of ice sheets or not ln_rafting = ', ln_rafting |
---|
905 | WRITE(numout,*) ' Parmeter thickness (threshold between ridge-raft) rn_hraft = ', rn_hraft |
---|
906 | WRITE(numout,*) ' Rafting hyperbolic tangent coefficient rn_craft = ', rn_craft |
---|
907 | WRITE(numout,*) ' Fraction of snow volume conserved during rafting rn_fsnwrft = ', rn_fsnwrft |
---|
908 | WRITE(numout,*) ' Fraction of pond volume conserved during rafting rn_fpndrft = ', rn_fpndrft |
---|
909 | ENDIF |
---|
910 | ! |
---|
911 | IF ( ( ln_str_H79 .AND. ln_str_R75 ) .OR. ( .NOT.ln_str_H79 .AND. .NOT.ln_str_R75 ) ) THEN |
---|
912 | CALL ctl_stop( 'ice_dyn_rdgrft_init: choose one and only one formulation for ice strength (ln_str_H79 or ln_str_R75)' ) |
---|
913 | ENDIF |
---|
914 | ! |
---|
915 | IF ( ( ln_partf_lin .AND. ln_partf_exp ) .OR. ( .NOT.ln_partf_lin .AND. .NOT.ln_partf_exp ) ) THEN |
---|
916 | CALL ctl_stop( 'ice_dyn_rdgrft_init: choose one and only one participation function (ln_partf_lin or ln_partf_exp)' ) |
---|
917 | ENDIF |
---|
918 | ! ! allocate tke arrays |
---|
919 | IF( ice_dyn_rdgrft_alloc() /= 0 ) CALL ctl_stop( 'STOP', 'ice_dyn_rdgrft_init: unable to allocate arrays' ) |
---|
920 | ! |
---|
921 | END SUBROUTINE ice_dyn_rdgrft_init |
---|
922 | |
---|
923 | #else |
---|
924 | !!---------------------------------------------------------------------- |
---|
925 | !! Default option Empty module NO ESIM sea-ice model |
---|
926 | !!---------------------------------------------------------------------- |
---|
927 | #endif |
---|
928 | |
---|
929 | !!====================================================================== |
---|
930 | END MODULE icedyn_rdgrft |
---|