this fixes the qsat calculation for large T (#1870)

erf-model · Oct 9, 2024 · 61da848 · 61da848
1 parent b48be61
commit 61da848
Showing 1 changed file with 20 additions and 5 deletions.
diff --git a/Source/Utils/ERF_Microphysics_Utils.H b/Source/Utils/ERF_Microphysics_Utils.H
@@ -34,6 +34,7 @@ amrex::Real erf_esati (amrex::Real t) {
 
  amrex::Real dtt = t-273.16;
  AMREX_ALWAYS_ASSERT(dtt>-85);
+
  amrex::Real esati;
  if (dtt > 0.0) {
  esati = 0.0;
@@ -59,9 +60,12 @@ amrex::Real erf_esatw (amrex::Real t) {
  amrex::Real const a7 = -0.952447341e-13;
  amrex::Real const a8 = -0.976195544e-15;
 
- amrex::Real dtt = t-273.16;
- AMREX_ALWAYS_ASSERT(dtt>-85);
- AMREX_ALWAYS_ASSERT(dtt<70);
+ amrex::Real dtt_in = t-273.16;
+ AMREX_ALWAYS_ASSERT(dtt_in>-85);
+ //
+ // Rather than assert dt < 70, we impose that the saturation pressure does not change above 70
+ //
+ amrex::Real dtt = std::min(dtt_in,70.);
  amrex::Real esatw = a0 + dtt*(a1+dtt*(a2+dtt*(a3+dtt*(a4+dtt*(a5+dtt*(a6+dtt*(a7+a8*dtt)))))));
  return esatw;
 }
@@ -111,8 +115,19 @@ amrex::Real erf_dtesatw (amrex::Real t) {
 
  amrex::Real dtt = t-273.16;
  AMREX_ALWAYS_ASSERT(dtt>-85);
- AMREX_ALWAYS_ASSERT(dtt<70);
- amrex::Real dtesatw = a0 + dtt*(a1+dtt*(a2+dtt*(a3+dtt*(a4+dtt*(a5+dtt*(a6+dtt*(a7+a8*dtt)))))));
+
+ amrex::Real dtesatw;
+
+ //
+ // Rather than assert dt < 70, we impose that the saturation pressure does not change above 70,
+ // hence the derivative is 0.
+ //
+ if (dtt >= 70.) {
+ dtesatw = amrex::Real(0.0);
+ } else {
+ dtesatw = a0 + dtt*(a1+dtt*(a2+dtt*(a3+dtt*(a4+dtt*(a5+dtt*(a6+dtt*(a7+a8*dtt)))))));
+ }
+
  return dtesatw;
 }