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subroutine da_thickness(pre_ma,tv_ma,ks,ke,tv1,tv2,layer1,layer2,pre1,pre2,thk) 1,2
!-----------------------------------------------------------------------
! Purpose: calculates the thickness between two layers
! using vertical integration of virtual temperatures.
! pre1 and pre2 are two pressures for the two layers
!-----------------------------------------------------------------------
implicit none
integer,intent(in) :: layer1,layer2 ! two layers
real, intent(in) :: tv1,tv2 ! virtual temp.
real, intent(in) :: pre1,pre2 ! pressure
integer,intent(in) :: ks,ke
real, intent(in) :: pre_ma(ks-1:ke+1)
real, intent(in) :: tv_ma(ks-1:ke+1)
real, intent(out) :: thk ! thickness
integer :: k
real :: p_tmp(ks-1:ke+1)
if (trace_use_dull) call da_trace_entry
("da_thickness")
! Thickness at the top and bottom parts of the layer.
thk = 0.5 * gas_constant/gravity * (tv1*log(pre_ma(layer1-1)/pre1) + &
tv2*log(pre2/pre_ma(layer2)) )
! Temporary pressure
p_tmp(layer1) = pre1
p_tmp(layer2-1) = pre2
do k = layer2, layer1-1
p_tmp(k) = pre_ma(k)
end do
! Vertical integration of the virtual temperature
do k=layer2,layer1-1
thk = thk + 0.5 * gas_constant/gravity * tv_ma(k) * log(p_tmp(k-1)/p_tmp(k+1))
end do
if (trace_use_dull) call da_trace_exit("da_thickness")
end subroutine da_thickness