anchor.diff:                      elseif (Kq_m(i,k,j)<1) then
                           Kq_m(i,k,j)=1
                       endif
  +                    if (land_mask(i,j) == kLC_WATER) Kq_m(i,k,j) = Kq_m(i,k,j) / 1000.0
                   enddo
  +
  +                ! rescale diffusion to cut down on excessive mixing
  +                Kq_m(its:ite,k,j) = Kq_m(its:ite, k,j) / diffusion_reduction
               enddo
   
               call pbl_diffusion(qv, th, cloud, ice, qrain, qsnow, rho, dz, its, ite, kts, kte, j)
  
positive.code: !!----------------------------------------------------------
  module pbl_simple
      use data_structures
      use domain_interface,   only : domain_t
      use options_interface,  only : options_t
  
  
negative.code:                 ! diffusion for scalars
                  Kq_m(its:ite,k,j) = K_m(its:ite,k,j) / prandtl_m(its:ite,k,j)
  
                  Kq_m(its:ite,k,j) = Kq_m(its:ite, k,j) * dt / ((dz(its:ite,k,j) + dz(its:ite,k+1,j))/2)
  
                  ! enforce limits specified in HP96
  