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subroutine da_w_adjustment_lin(xb,W_a,WZ_a) 1,3
!---------------------------------------------------------------------------
! Purpose: Adjust vertical velocity increments
!
! Assumptions: 1) Model level stored top down.
!---------------------------------------------------------------------------
implicit none
type (xb_type), intent(in) :: xb ! first guess structure.
real, intent(out) :: w_a(ims:ime,jms:jme,kms:kme)
real, intent(inout) :: wz_a(ims:ime,jms:jme,kms:kme)
integer :: i,j,k
real :: wz_b(ims:ime,jms:jme,kms:kme)
real :: ebxl1,ebxl2
real :: ebxl19,ebxl29
if (trace_use) call da_trace_entry
("da_w_adjustment_lin")
call da_wz_base(xb,WZ_b)
do j=jts,jte
do i=its,ite
ebxl1=0.0
ebxl19=0.0
ebxl2=0.0
ebxl29=0.0
do k=kte,kts,-1
ebxl1=ebxl1+wz_a(i,j,k)*(xb%hf(i,j,k)-xb%hf(i,j,k+1))
ebxl19=ebxl19+wz_b(i,j,k)*(xb%hf(i,j,k)-xb%hf(i,j,k+1))
ebxl2=ebxl2+wz_a(i,j,k)*(xb%hf(i,j,k)-xb%hf(i,j,k+1)) &
*sign(1.0,wz_b(i,j,k))
ebxl29=ebxl29+abs(wz_b(i,j,k))*(xb%hf(i,j,k)-xb%hf(i,j,k+1))
end do
do k=kts,kte
wz_a(i,j,k)=wz_a(i,j,k)*(1.-ebxl19/ebxl29*sign(1.0,wz_b(i,j,k)))- &
ebxl1*abs(wz_b(i,j,k))/ebxl29+ &
ebxl2*abs(wz_b(i,j,k))*ebxl19/ebxl29**2
end do
end do
end do
if (trace_use) call da_trace_exit("da_w_adjustment_lin")
end subroutine da_w_adjustment_lin