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subroutine da_find_layer(layer,tv,pre,pre_ma,tv_ma,ks,ke) 4,2
!-----------------------------------------------------------------------
! Purpose: find the vertical location in the Tv profile given
! a specific pressure and vertically interpolate Tv to that height.
! pre_ma,tv_ma give vertical profile of virtual temperature
! pre is a given pressure, alpha is the percentage of pre in the layer.
! layer,tv are calculated vertical layer and interpolated virtual temp.
!-----------------------------------------------------------------------
implicit none
integer, intent(in) :: ks, ke
integer, intent(inout) :: layer
real, intent(inout) :: pre_ma(ks-1:ke+1)
real, intent(in) :: tv_ma(ks-1:ke+1)
real, intent(in) :: pre
real, intent(inout) :: tv
integer :: k
real :: alpha
if (trace_use_frequent) call da_trace_entry
("da_find_layer")
if (pre >= pre_ma(ks)) then
! Below model bottom
layer = ks
alpha = log(pre_ma(ks)/pre)/log(pre_ma(ks)/pre_ma(ks+1))
tv = tv_ma(ks) * (1.0-alpha) + tv_ma(ks+1) * alpha
pre_ma(ks-1)=pre
else if (pre <= pre_ma(ke)) then
! Above model top
layer = ke+1
alpha = log(pre_ma(ke-1)/pre)/log(pre_ma(ke-1)/pre_ma(ke))
tv = tv_ma(ke-1) * (1.0-alpha) + tv_ma(ke) * alpha
pre_ma(ke+1) = pre
else
! Between model layers
do k=ks,ke-1
if (pre>=pre_ma(k+1) .and. pre<pre_ma(k)) then
layer = k+1
alpha = log(pre_ma(k)/pre)/log(pre_ma(k)/pre_ma(k+1))
tv = tv_ma(k) * (1.0-alpha) + tv_ma(k+1) * alpha
exit
end if
end do
end if
if (trace_use_frequent) call da_trace_exit("da_find_layer")
end subroutine da_find_layer