diff --git a/Source/BoundaryConditions/BoundaryConditions_cons.cpp b/Source/BoundaryConditions/BoundaryConditions_cons.cpp
index befa578a..634938c0 100644
--- a/Source/BoundaryConditions/BoundaryConditions_cons.cpp
+++ b/Source/BoundaryConditions/BoundaryConditions_cons.cpp
@@ -45,9 +45,11 @@ void REMORAPhysBCFunct::impose_cons_bcs (const Array4<Real>& dest_arr, const Box
 
     GpuArray<GpuArray<Real, AMREX_SPACEDIM*2>,AMREX_SPACEDIM+NCONS> l_bc_extdir_vals_d;
 
-    for (int i = 0; i < ncomp; i++)
-        for (int ori = 0; ori < 2*AMREX_SPACEDIM; ori++)
+    for (int i = 0; i < ncomp; i++) {
+        for (int ori = 0; ori < 2*AMREX_SPACEDIM; ori++) {
             l_bc_extdir_vals_d[i][ori] = m_bc_extdir_vals[bccomp+i][ori];
+        }
+    }
 
     GeometryData const& geomdata = m_geom.data();
     bool is_periodic_in_x = geomdata.isPeriodic(0);
diff --git a/Source/Particles/TracerPC.H b/Source/Particles/TracerPC.H
index c0d87d42..b1eab157 100644
--- a/Source/Particles/TracerPC.H
+++ b/Source/Particles/TracerPC.H
@@ -66,4 +66,32 @@ public:
                          amrex::MultiFab& a_z_height);
 };
 
+    template <typename P>
+    AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
+    void update_location_idata (P& p,
+                                amrex::GpuArray<amrex::Real,AMREX_SPACEDIM> const& plo,
+                                amrex::GpuArray<amrex::Real,AMREX_SPACEDIM> const& dxi,
+                                const amrex::Array4<amrex::Real const>&  height_arr)
+    {
+        amrex::IntVect iv( int(amrex::Math::floor((p.pos(0)-plo[0])*dxi[0])),
+                           int(amrex::Math::floor((p.pos(1)-plo[1])*dxi[1])),
+                           p.idata(0) );
+
+        amrex::Real lx = (p.pos(0)-plo[0])*dxi[0] - static_cast<amrex::Real>(iv[0]);
+        amrex::Real ly = (p.pos(1)-plo[1])*dxi[1] - static_cast<amrex::Real>(iv[1]);
+        auto zlo = height_arr(iv[0]  ,iv[1]  ,iv[2]  ) * (1.0-lx) * (1.0-ly) +
+                   height_arr(iv[0]+1,iv[1]  ,iv[2]  ) *      lx  * (1.0-ly) +
+                   height_arr(iv[0]  ,iv[1]+1,iv[2]  ) * (1.0-lx) * ly +
+                   height_arr(iv[0]+1,iv[1]+1,iv[2]  ) *      lx  * ly;
+        auto zhi = height_arr(iv[0]  ,iv[1]  ,iv[2]+1) * (1.0-lx) * (1.0-ly) +
+                   height_arr(iv[0]+1,iv[1]  ,iv[2]+1) *      lx  * (1.0-ly) +
+                   height_arr(iv[0]  ,iv[1]+1,iv[2]+1) * (1.0-lx) * ly +
+                   height_arr(iv[0]+1,iv[1]+1,iv[2]+1) *      lx  * ly;
+
+        if (p.pos(2) > zhi) {
+            p.idata(0) += 1;
+        } else if (p.pos(2) <= zlo) {
+            p.idata(0) -= 1;
+        }
+    }
 #endif
diff --git a/Source/Particles/TracerPC.cpp b/Source/Particles/TracerPC.cpp
index 70848846..48ba211c 100644
--- a/Source/Particles/TracerPC.cpp
+++ b/Source/Particles/TracerPC.cpp
@@ -135,7 +135,7 @@ TracerPC::AdvectWithUmac (Array<MultiFab const*, AMREX_SPACEDIM> umac,
                 ParticleType& p = p_pbox[i];
                 if (p.id() <= 0) { return; }
                 ParticleReal v[AMREX_SPACEDIM];
-                mac_interpolate(p, plo, dxi, umacarr, v);
+                mac_interpolate_mapped_z(p, plo, dxi, umacarr, zheight, v);
                 if (ipass == 0)
                 {
                     for (int dim=0; dim < AMREX_SPACEDIM; dim++)
@@ -161,24 +161,15 @@ TracerPC::AdvectWithUmac (Array<MultiFab const*, AMREX_SPACEDIM> umac,
                     iv[1] += domain.smallEnd()[1];
                     ParticleReal zlo, zhi;
                     if (use_terrain) {
-                        Real lx = (p.pos(0)-plo[0])*dxi[0] - static_cast<Real>(iv[0]-domain.smallEnd()[0]);
-                        Real ly = (p.pos(1)-plo[1])*dxi[1] - static_cast<Real>(iv[1]-domain.smallEnd()[1]);
-                        zlo =  zheight(iv[0]  ,iv[1]  ,iv[2]  ) * (1.0_rt-lx) * (1.0_rt-ly) +
-                               zheight(iv[0]+1,iv[1]  ,iv[2]  ) *      lx  * (1.0_rt-ly) +
-                               zheight(iv[0]  ,iv[1]+1,iv[2]  ) * (1.0_rt-lx) * ly +
-                               zheight(iv[0]+1,iv[1]+1,iv[2]  ) *      lx  * ly;
-                        zhi =  zheight(iv[0]  ,iv[1]  ,iv[2]+1) * (1.0_rt-lx) * (1.0_rt-ly) +
-                               zheight(iv[0]+1,iv[1]  ,iv[2]+1) *      lx  * (1.0_rt-ly) +
-                               zheight(iv[0]  ,iv[1]+1,iv[2]+1) * (1.0_rt-lx) * ly +
-                               zheight(iv[0]+1,iv[1]+1,iv[2]+1) *      lx  * ly;
+                        update_location_idata(p,plo,dxi,zheight);
                     } else {
                         zlo =  iv[2]    * dx[2];
                         zhi = (iv[2]+1) * dx[2];
-                    }
-                    if (p.pos(2) > zhi) { // need to be careful here
-                        p.idata(0) += 1;
-                    } else if (p.pos(2) <= zlo) {
-                        p.idata(0) -= 1;
+                        if (p.pos(2) > zhi) { // need to be careful here
+                            p.idata(0) += 1;
+                        } else if (p.pos(2) <= zlo) {
+                            p.idata(0) -= 1;
+                        }
                     }
                 }
             });
diff --git a/Submodules/AMReX b/Submodules/AMReX
index e0b77e1f..d121723c 160000
--- a/Submodules/AMReX
+++ b/Submodules/AMReX
@@ -1 +1 @@
-Subproject commit e0b77e1fce491021696d22f1496138e8d9942d65
+Subproject commit d121723c7491acedf8e2e010cfb1bf3773224b95