enkftv_module.f90

CLM集合卡曼滤波数据同化算法

  MODULE enkftv_module

!  -------------------------------------------------------------------
! |   clmtv_ensemble_module is modified from clmtv_module written by  |
! |   Dai Yongjiu. This module is used for defining the ensemble of   |   
! |   time-varying variables in CLM which will be utilized to perform |
! |   the data assimilation of remote sensing data with the ensemble  |
! |   kalman filtering techniques. the original variables defined in  |
! |   clmtv_module are increased to 3 dimensions, the third one of    |
! |   which represents the ensemble size. In clmtv_ensemble_module,   |
! |   all time-varying variables have the allocatable attribute. The  |
! |   concrete space will be assigned to them in clm_ini.f90 by using |
! |   subroutine clmtv_ensemble_allocate. As for detailed physical    |
! |   meanings,please read CLM code.                                  |
! |                                                                   |
! |   Source file: enkftv_module.f90                                  |
! |   first version: QinJun Dai, Yongjiu May 26, 2004                 |
!  ------------------------------------------------------------------

        IMPLICIT NONE

!  Note that the prefix "en" of orignal CLM variables represent "ensemble"

! -----------------------------------------------------------------
! [1] main land surface variables needed for restart
! -----------------------------------------------------------------

  integer, dimension(:,:), allocatable :: &
        en_snl          ! number of snow layers

! In the subroutine clmtv_ensemble_allocate, the directive allocate
! (en_snl(1:kpt,1:Ne)) will be used to assign space for variable snl.
! As for other varialbes, the similar directives will be exploited.

  real, dimension(:,:,:), allocatable :: &
        en_dz,         &! layer thickiness [m]
        en_z,          &! node depth [m]
        en_zi,         &! interface depth [m]
        en_tss,        &! soil temperature [K]
        en_wliq,       &! liquid water in layers [kg/m2]
        en_wice,       &! ice lens in layers [kg/m2]
        en_rootr        ! root resistance of a layer, all layers add to 1.0

  real, dimension(:,:), allocatable :: &
        en_green,      &!
        en_fveg,       &! fraction of vegetation cover
        en_fsno,       &! fraction of snow cover on ground
        en_sigf,       &! fraction of veg cover, excluding snow-covered veg [-]
        en_tlsun,      &! sunlit leaf temperature [K]
        en_tlsha,      &! shaded leaf temperature [K]
        en_ldew,       &! depth of water on foliage [mm]
        en_sag,        &! non dimensional snow age [-]
        en_scv,        &! snow cover, water equivalent [mm]
        en_snowdp,     &! snow depth [meter]
        en_etrc,       &! maximum possible transpiration rate [mm/s]
        en_tg           ! ground surface temperature [K]

  real, dimension(:,:), allocatable :: &
        en_xerr,       &! accumulation of the error of water banace
        en_zerr         ! accumulation of the error of energy balance

! -----------------------------------------------------------------
! [2] vegetation dynamic parameters 
! -----------------------------------------------------------------

  real, dimension(:,:), allocatable :: &
        en_lai,        &! leaf area index
        en_sai          ! stem area index

! -----------------------------------------------------------------
! [3] albedo calculation for next time step
! -----------------------------------------------------------------

  real, dimension(:,:,:,:), allocatable :: &
        en_albg,       &! albedo, ground [-]
        en_albv,       &! albedo, vegetation [-]
        en_alb,        &! averaged albedo [-]
        en_ssun,       &!
        en_ssha,       &!
        en_tranc        ! canopy transmittances for solar radiation

  real, dimension(:,:), allocatable :: &
        en_thermk,     &! canopy gap fraction for tir radiation
        en_extkb,      &! (k, g(mu)/mu) direct solar extinction coefficient
        en_extkd        ! diffuse and scattered diffuse PAR extinction coefficient

! -----------------------------------------------------------------
! [4] currrnt julian day (including fraction), year for next time step
! -----------------------------------------------------------------
  integer ,dimension(:),allocatable :: &
        en_iyear,      &! current year of model run
        en_jday,       &! current julian day of model run
        en_mcsec        ! current seconds of model run (0 - 86400)

! Here note that current year,current julian day and current seconds
! also need increasing dimension for the calculation structure of 
! clm_drv.f90. They will run to the next time step for computing parameters
! needed in the next clm_main() calculation.

  real, dimension(:,:), allocatable :: &
        en_cosz         ! cosine of solar zenith angle

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

  END MODULE enkftv_module