enkf_add_noise.f90

CLM集合卡曼滤波数据同化算法

   subroutine enkf_add_noise(istep)
! ---------------------------------------------------------------------
!| this subroutine is used for adding model noise into the model       |
!| state variables                                                     |  
!|                                                                     |
!|                                                                     |
!|                                                                     |
!| first version date: 7/23/2004, author: QinJun                       | 
!| modifying date    : 8/19/2004, by QinJun                            |
! ---------------------------------------------------------------------
         use clmtv_module
	 use clmtc_module
	 use clmpar_module
	 use enkftv_module
	 use enkfpar_module

	 implicit none

	 real::gasdev     ! declaration for function gasdev() used to generate
	                  ! random number with distribution N(0,1)

	 real,dimension(1:10)::RAND ! realization of independent 32-dimensional
	                            ! multivariate random vector

	 real,dimension(1:10)::MN   ! realization of model noise

	 real,dimension(1:10,1:10)::SQRTW ! square root of model error

	 integer:: i, j, k, m, n    ! iteration cycle number

         real, dimension(1:10)    :: SV ! denote  state variables for temporary
                                        ! use 
         integer :: istep

	 do i = 1, kpt

!    ------------------------------------------- 
!    ** produce model noise with a new method **
!    -------------------------------------------

           do m = 1, 10

              SV(m) = tss(m,i) 

           end do

           do m = 1, 10 

              do n = 1,10 
                 
                 W(m,n) = Rhoc(m,n)*ABS(Sigman(m)*Sigman(n)*SV(m)*SV(n))
!print*, Rhoc

              end do

           end do 
!print*, 'sigman',Sigman(21) 
!print*, 'SV',SV
!print*, 'Rhoc',Rhoc(21,21)
!print*, 'W',W(21,21)
!write(7777,*)((W(m,n),n=1,21),m=1,21)
!print*,'MATMULT',MN
print*, 'new methods', istep

!    --------------------------------------------------------------- 
! write(*,*) ((W(m,n),n=1,10),m=1,10) 


          call PDSQRT(W,SQRTW,10) 
!print*,'PDSQRT'
!print*,'MATMULT',MN
	   do j = 1, Ne
!print*,j
	         do m =1, 10 

		   RAND(m) = gasdev(idum)!*sqrt(dtime)

		 end do 
!print*,' RAND'

!print*,'PDSQRT'
                 call MATMULT(SQRTW,RAND,MN,10,10,1)
!print*,'MATMULT',MN
		 do m = 1, 10

		      en_tss(m,i,j) = en_tss(m,i,j) + MN(m)

		 end do
print*,'en_tss',en_tss(:,i,j)
!print*,'en_tlsun'
		 en_tg(i,j) = en_tss(1,i,j)    ! in CLM, tg(?) = tss(1,?)
!print*,'en_tg'
!print*, j
	   end do
!print*,'end do'

       end do






   end subroutine enkf_add_noise