!= 地下における熱の鉛直拡散
!
!= Vertical diffusion of heat under the ground
!
! Authors::   Yoshiyuki O. Takahashi
! Version::   $Id: subsurface_diffusion_heat.f90,v 1.10 2015/01/29 12:07:59 yot Exp $
! Tag Name::  $Name:  $
! Copyright:: Copyright (C) GFD Dennou Club, 2008-2009. All rights reserved.
! License::   See COPYRIGHT[link:../../../COPYRIGHT]
!

module subsurface_diffusion_heat
  !
  != 地下の鉛直拡散
  !
  != Vertical diffusion under the ground
  !
  ! <b>Note that Japanese and English are described in parallel.</b>
  !
  !== Procedures List
  !
  ! SubsurfaceDiffusion     :: 熱伝導フラックスの計算
  ! SubsurfaceDiffusionInit :: 初期化サブルーチン
  ! ----------------------- :: ------------
  ! SubsurfaceDiffusion     :: Calculate thermal conduction flux
  ! SubsurfaceDiffusionInit :: Initialization
  !
  !--
  !== NAMELIST
  !
  ! NAMELIST#subsurface_diffusion_heat_nml
  !++

  ! モジュール引用 ; USE statements
  !

  ! 格子点設定
  ! Grid points settings
  !
  use gridset, only:   imax, & ! 経度格子点数. 
                               ! Number of grid points in longitude
    &                  jmax, & ! 緯度格子点数. 
                               ! Number of grid points in latitude
    &                  kmax, & ! 鉛直層数. 
                               ! Number of vertical level
    &                  kslmax  ! 地下の鉛直層数. 
                               ! Number of subsurface vertical level

  ! 種別型パラメタ
  ! Kind type parameter
  !
  use dc_types, only: DP, &      ! 倍精度実数型. Double precision. 
    &                 STRING     ! 文字列.       Strings. 

  ! メッセージ出力
  ! Message output
  !
  use dc_message, only: MessageNotify

  ! 宣言文 ; Declaration statements
  !
  implicit none
  private

  ! 公開手続き
  ! Public procedure
  !
!!$  public:: SubsurfaceDiffusionFlagLand
  public:: SubsurfaceDiffusion
  public:: SubsurfaceDiffusionInit

  ! 公開変数
  ! Public variables
  !

  ! 非公開変数
  ! Private variables
  !
  logical, save :: subsurface_diffusion_inited = .false.
                              ! 初期設定フラグ. 
                              ! Initialization flag

  character(*), parameter:: module_name = 'subsurface_diffusion_heat'
                              ! モジュールの名称. 
                              ! Module name
  character(*), parameter:: version = &
    & '$Name:  $' // &
    & '$Id: subsurface_diffusion_heat.f90,v 1.10 2015/01/29 12:07:59 yot Exp $'
                              ! モジュールのバージョン
                              ! Module version

contains

  !--------------------------------------------------------------------------------------

!!$  subroutine SubsurfaceDiffusionFlagLand(  &
!!$    & xy_SurfType,                         & ! (in)
!!$    & xy_FlagMatthewsLand                  & ! (out)
!!$    & )
!!$    !
!!$    !
!!$    !
!!$    ! Set index for calculation method from Matthews' index
!!$    !
!!$
!!$    ! モジュール引用 ; USE statements
!!$    !
!!$
!!$    ! 雪と海氷の定数の設定
!!$    ! Setting constants of snow and sea ice
!!$    !
!!$    use constants_snowseaice, only: &
!!$      & SeaIceThreshold
!!$
!!$
!!$    ! 宣言文 ; Declaration statements
!!$    !
!!$
!!$    integer , intent(in ) :: xy_SurfType        (0:imax-1, 1:jmax)
!!$                              ! 土地利用.
!!$                              ! Surface index
!!$    logical , intent(out) :: xy_FlagMatthewsLand(0:imax-1, 1:jmax)
!!$                              ! 
!!$                              ! Flag for land grid box
!!$
!!$
!!$    ! 作業変数
!!$    ! Work variables
!!$    !
!!$
!!$    integer:: i               ! 経度方向に回る DO ループ用作業変数
!!$                              ! Work variables for DO loop in longitude
!!$    integer:: j               ! 緯度方向に回る DO ループ用作業変数
!!$                              ! Work variables for DO loop in latitude
!!$
!!$
!!$    ! 実行文 ; Executable statement
!!$    !
!!$
!!$    ! 初期化確認
!!$    ! Initialization check
!!$    !
!!$    if ( .not. subsurface_diffusion_inited ) then
!!$      call MessageNotify( 'E', module_name, 'This module has not been initialized.' )
!!$    end if
!!$
!!$    !
!!$    ! Set flag for land
!!$    !
!!$    do j = 1, jmax
!!$      do i = 0, imax-1
!!$        if ( xy_SurfType(i,j) >= 1 ) then
!!$          ! land
!!$          xy_FlagMatthewsLand(i,j) = .true.
!!$        else
!!$          ! others
!!$          xy_FlagMatthewsLand(i,j) = .false.
!!$        end if
!!$      end do
!!$    end do
!!$
!!$
!!$  end subroutine SubsurfaceDiffusionFlagLand

  !--------------------------------------------------------------------------------------

  subroutine SubsurfaceDiffusion(              &
    & xy_DeepSubSurfHeatFlux,                  &          ! (in )
    & xy_SoilHeatCap, xy_SoilHeatDiffCoef,     &          ! (in )
    & xy_SurfTemp, xyz_SoilTemp, xy_SurfSnowB, &          ! (in )
    & xyr_SoilTempTransCoef, xyr_SoilHeatFlux  &          ! (out)
    & )
    !
    ! 時間変化率の計算を行います. 
    !
    ! Calculate tendencies. 
    !

    ! モジュール引用 ; USE statements
    !

    ! 時刻管理
    ! Time control
    !
    use timeset, only: &
      & TimesetClockStart, TimesetClockStop

    ! 座標データ設定
    ! Axes data settings
    !
    use axesset, only: &
      z_SSDepth    ! subsurface grid at midpoint of layer

    ! 雪と海氷の定数の設定
    ! Setting constants of snow and sea ice
    !
    use constants_snowseaice, only: &
      & SnowDens,            &
      & SnowMaxThermDepth,   &
      & SnowThermCondCoef

    ! 宣言文 ; Declaration statements
    !
    implicit none

    real(DP), intent(in ):: xy_DeepSubSurfHeatFlux (0:imax-1, 1:jmax)
                              ! 地中熱フラックス. 
                              ! "Deep subsurface heat flux"
                              ! Heat flux at the bottom of surface/soil layer.
    real(DP), intent(in ):: xy_SoilHeatCap (0:imax-1, 1:jmax)
                              ! 土壌熱容量 (J K-1 kg-1)
                              ! Specific heat of soil (J K-1 kg-1)
    real(DP), intent(in ):: xy_SoilHeatDiffCoef (0:imax-1, 1:jmax)
                              ! 土壌熱伝導係数 (J m-3 K-1)
                              ! Heat conduction coefficient of soil (J m-3 K-1)
    real(DP), intent(in ):: xy_SurfTemp (0:imax-1, 1:jmax)
                              ! 地表面温度. 
                              ! Surface temperature
    real(DP), intent(in ):: xyz_SoilTemp (0:imax-1, 1:jmax, 1:kslmax)
                              ! 土壌温度 (K)
                              ! Soil temperature (K)
    real(DP), intent(in ):: xy_SurfSnowB (0:imax-1, 1:jmax)
                              ! 積雪量.
                              ! Surface snow amount.
    real(DP), intent(out):: xyr_SoilTempTransCoef (0:imax-1, 1:jmax, 0:kslmax)
                              ! 輸送係数：土壌温度.
                              ! Transfer coefficient: soil temperature
    real(DP), intent(out):: xyr_SoilHeatFlux (0:imax-1, 1:jmax, 0:kslmax)
                              ! 土壌中の熱フラックス. 
                              ! Heat flux in sub-surface soil



    ! 作業変数
    ! Work variables
    !
    real(DP) :: xy_SnowDepth             (0:imax-1, 1:jmax)
    real(DP) :: xy_SurfTransCoefCorFactor(0:imax-1, 1:jmax)

    integer:: k               ! 鉛直方向に回る DO ループ用作業変数
                              ! Work variables for DO loop in vertical direction

    ! 実行文 ; Executable statement
    !

    ! 初期化確認
    ! Initialization check
    !
    if ( .not. subsurface_diffusion_inited ) then
      call MessageNotify( 'E', module_name, 'This module has not been initialized.' )
    end if


    ! 計算時間計測開始
    ! Start measurement of computation time
    !
    call TimesetClockStart( module_name )



    ! 土壌温度計算用の輸送係数の計算
    ! Calculate transfer coefficient for heat diffusion in the soil
    !
    k = 0
    if ( kslmax == 0 ) then
      ! This line is used when kslmax == 0, because z_SSDepth(k+1) does not exist. 
      xyr_SoilTempTransCoef(:,:,k) = 0.0_DP
    else
!!$      xyr_SoilTempTransCoef(:,:,k) = &
!!$        & xy_SoilHeatDiffCoef(:,:) / ( z_SSDepth(k+1) - 0.0_DP )
!!$      xyr_SoilTempTransCoef(:,:,k) =                                          &
!!$        & (   ( z_SSDepth(k+1) - 0.0_DP ) / xy_SoilHeatDiffCoef               &
!!$        &   - min( max( xy_SurfSnowB / SnowDens, 0.0_DP ), SnowMaxThermDepth )&
!!$        &     / SnowThermCondCoef )**(-1)
      xyr_SoilTempTransCoef(:,:,k) = &
        & xy_SoilHeatDiffCoef(:,:) / ( z_SSDepth(k+1) - 0.0_DP )
      xy_SnowDepth = min( max( xy_SurfSnowB / SnowDens, 0.0_DP ), &
        &                 SnowMaxThermDepth                       )
      xy_SurfTransCoefCorFactor = &
        &   SnowThermCondCoef * ( z_SSDepth(k+1) - 0.0_DP )             &
        &     / (   SnowThermCondCoef   * ( z_SSDepth(k+1) - 0.0_DP )   &
        &         + xy_SoilHeatDiffCoef * ( 0.0_DP - xy_SnowDepth   ) )
      xyr_SoilTempTransCoef(:,:,k) = xyr_SoilTempTransCoef(:,:,k)   &
        & * xy_SurfTransCoefCorFactor

    end if
    do k = 1, kslmax-1
      xyr_SoilTempTransCoef(:,:,k) = &
        & xy_SoilHeatDiffCoef(:,:) / ( z_SSDepth(k+1) - z_SSDepth(k) )
    end do
    k = kslmax
    xyr_SoilTempTransCoef(:,:,k) = 0.0_DP


    ! 土壌中の熱フラックスの計算
    ! Calculate heat flux in sub-surface soil
    !
    k = 0
    if ( kslmax == 0 ) then
      ! This line is used when kslmax == 0, because xyz_SoilTemp(:,:,k+1) does not exist. 
      xyr_SoilHeatFlux(:,:,k) = 0.0_DP
    else
      xyr_SoilHeatFlux(:,:,k) = &
        & - xyr_SoilTempTransCoef(:,:,k) * ( xyz_SoilTemp(:,:,1) - xy_SurfTemp(:,:) )
    end if
    do k = 1, kslmax-1
      xyr_SoilHeatFlux(:,:,k) =                               &
        & - xyr_SoilTempTransCoef(:,:,k)                      &
        &   * ( xyz_SoilTemp(:,:,k+1) - xyz_SoilTemp(:,:,k) )
    end do
    k = kslmax
    xyr_SoilHeatFlux(:,:,k) = xy_DeepSubSurfHeatFlux


    ! 計算時間計測一時停止
    ! Pause measurement of computation time
    !
    call TimesetClockStop( module_name )

  end subroutine SubsurfaceDiffusion

  !-------------------------------------------------------------------

  subroutine SubsurfaceDiffusionInit
    !
    ! subsurface_diffusion_heat モジュールの初期化を行います. 
    ! NAMELIST#subsurface_diffusion_heat_nml の読み込みはこの手続きで行われます. 
    !
    ! "subsurface_diffusion_heat" module is initialized. 
    ! "NAMELIST#subsurface_diffusion_heat_nml" is loaded in this procedure. 
    !

    ! モジュール引用 ; USE statements
    !

    ! NAMELIST ファイル入力に関するユーティリティ
    ! Utilities for NAMELIST file input
    !
!!$    use namelist_util, only: namelist_filename, NmlutilMsg, NmlutilAryValid

    ! ファイル入出力補助
    ! File I/O support
    !
    use dc_iounit, only: FileOpen

    ! 種別型パラメタ
    ! Kind type parameter
    !
    use dc_types, only: STDOUT ! 標準出力の装置番号. Unit number of standard output

    ! 文字列操作
    ! Character handling
    !
    use dc_string, only: StoA

    ! ヒストリデータ出力
    ! History data output
    !
    use gtool_historyauto, only: HistoryAutoAddVariable

    ! メッセージ出力
    ! Message output
    !
    use dc_message, only: MessageNotify

    ! 宣言文 ; Declaration statements
    !
    implicit none

    ! 作業変数
    ! Work variables
    !
!!$    integer:: unit_nml        ! NAMELIST ファイルオープン用装置番号. 
!!$                              ! Unit number for NAMELIST file open
!!$    integer:: iostat_nml      ! NAMELIST 読み込み時の IOSTAT. 
!!$                              ! IOSTAT of NAMELIST read

!!$    real(DP) :: SoilHeatCap
!!$    real(DP) :: SoilHeatDiffCoef

    ! NAMELIST 変数群
    ! NAMELIST group name
    !
!!$    namelist /subsurface_diffusion_heat_nml/ &
!!$      & SoilHeatCap, SoilHeatDiffCoef
!!$          !
!!$          ! デフォルト値については初期化手続 "subsurface_diffusion_heat#SubSurfaceDiffusionInit" 
!!$          ! のソースコードを参照のこと. 
!!$          !
!!$          ! Refer to source codes in the initialization procedure
!!$          ! "subsurface_diffusion_heat#SubsurfaceDiffusionInit" for the default values. 
!!$          !

    ! 実行文 ; Executable statement
    !

    if ( subsurface_diffusion_inited ) return

    ! デフォルト値の設定
    ! Default values settings
    !


    ! NAMELIST の読み込み
    ! NAMELIST is input
    !
!!$    if ( trim(namelist_filename) /= '' ) then
!!$      call FileOpen( unit_nml, &          ! (out)
!!$        & namelist_filename, mode = 'r' ) ! (in)
!!$
!!$      rewind( unit_nml )
!!$      read( unit_nml, &           ! (in)
!!$        & nml = subsurface_diffusion_heat_nml, &  ! (out)
!!$        & iostat = iostat_nml )   ! (out)
!!$      close( unit_nml )
!!$
!!$      call NmlutilMsg( iostat_nml, module_name ) ! (in)
!!$    end if


    ! 印字 ; Print
    !
    call MessageNotify( 'M', module_name, '----- Initialization Messages -----' )
    call MessageNotify( 'M', module_name, '-- version = %c', c1 = trim(version) )

    subsurface_diffusion_inited = .true.

  end subroutine SubsurfaceDiffusionInit

  !-------------------------------------------------------------------

end module subsurface_diffusion_heat
