htrdr

commit ba48d2de98321966d59961a2bcbc51a6ad103fa7
parent 32d231f97abea09e0aac1feb0e2361f3e45411cd
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Thu, 20 Feb 2025 14:45:22 +0100

planets: fixing the longwave volume radiation balance

In longwave, the gas temperature at the sampled position must be treated
as a source. But this position position may be outside the gas. This
commit handles this case by returning a zero source.

Diffstat:
M
src/planets/htrdr_planets_solve_volrad_budget.c
 | 
16
++++++++++++----

1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/src/planets/htrdr_planets_solve_volrad_budget.c b/src/planets/htrdr_planets_solve_volrad_budget.c
@@ -131,19 +131,27 @@ get_source
   switch(cmd->spectral_domain.type) {
     case HTRDR_SPECTRAL_SW:
       /* In shortwave, the source is external to the system */
-      source = 0;
+      source = 0; /* [W/m^2/sr/m] */
       break;
 
     case HTRDR_SPECTRAL_LW:
       RNATM(fetch_cell(cmd->atmosphere, pos, RNATM_GAS, &cell_pos));
-      RNATM(cell_get_gas_temperature(cmd->atmosphere, &cell_pos, &temperature));
-      source = htrdr_planck_monochromatic(wlen_m, temperature); /* [W/m^2/sr/m] */
+
+      if(SUVM_PRIMITIVE_NONE(&cell_pos.prim)) {
+        /* The position is not in the gas */
+        source = 0; /* [W/m^2/sr/m] */
+
+      } else {
+        /* Fetch the source temperature */
+        RNATM(cell_get_gas_temperature(cmd->atmosphere, &cell_pos, &temperature));
+        source = htrdr_planck_monochromatic(wlen_m, temperature); /* [W/m^2/sr/m] */
+      }
       break;
 
     default: FATAL("Unreachable code\n"); break;
   }
 
-  return source;
+  return source; /* [W/m^2/sr/m] */
 }
 
 /* Return the total absorption coefficient,