anchor.diff:  !!  linear_perturb->[ setup_linwinds -> add_buffer_topo,
   !!                    calc_domain_stability,
   !!                    linear_winds -> various fft routines]
  -!! 
  +!!
   !! High level routine descriptions / purpose
   !!   calc_domain_stability    - calculates a mean Brunt Vaisala frequency over the domain
   !!   linear_winds             - primary routine that calculates the linear wind perturbation
  
positive.code:                 do i=1,nx
                      xs=max(1, i-window)
                      xe=min(nx,i+window)
                      
                      ys=max(1, buffer-j+1-window)
                      ye=min(ny,buffer-j+1+window)
                  
                      buffer_topo(i,buffer-j+1)=sum(buffer_topo(xs:xe,ys:ye))/((xe-xs+1) * (ye-ys+1))
  
                      ys=max(1, ny-(buffer-j)-window)
                      ye=min(ny,ny-(buffer-j)+window)
                  
                      buffer_topo(i,ny-(buffer-j))=sum(buffer_topo(xs:xe,ys:ye))/((xe-xs+1) * (ye-ys+1))
                  end do
                  ! smooth the left and right borders
  
negative.code:             U_layers(i)=sum(preU_layers(bottom:top))/(top-bottom+1)
              V_layers(i)=sum(preV_layers(bottom:top))/(top-bottom+1)
          enddo
  
          if (.not.data_allocated) then
              if (debug) then
                  write(*,"(A,A)") char(13),"Allocating Linear Wind Data and FFTW plans"
  