refactor: streamlined dz_dt computation in Parcel class and updated planetary pressure units

Author: mzsuetam

PySDM/environments/parcel.py

@@ -106,7 +106,7 @@ def advance_parcel_vars(self):
         T = self["T"][0]
         p = self["p"][0]
 
-        dz_dt = self.w((self.particulator.n_steps + 1 / 2) * dt)  # "mid-point"
+        dz_dt = self._compute_dz_dt(dt)
         water_vapour_mixing_ratio = (
             self["water_vapour_mixing_ratio"][0]
             - self.delta_liquid_water_mixing_ratio / 2
@@ -133,6 +133,9 @@ def advance_parcel_vars(self):
             (self._tmp["rhod"][0] + self["rhod"][0]) / 2, self.mass_of_dry_air
         )
 
+    def _compute_dz_dt(self, dt):
+        self.w((self.particulator.n_steps + 1 / 2) * dt)  # "mid-point"
+
     def get_thd(self):
         return self["thd"]
 

examples/PySDM_examples/Loftus_and_Wordsworth_2021/parcel.py

@@ -25,38 +25,5 @@ def __init__(
             variables=None,
         )
 
-    def advance_parcel_vars(self):
-        """
-        Compute new values of displacement, dry-air density and volume,
-        and write them to self._tmp and self.mesh.dv
-        """
-        dt = self.particulator.dt
-        formulae = self.particulator.formulae
-        T = self["T"][0]
-        p = self["p"][0]
-
-        dz_dt = -self.particulator.attributes["terminal velocity"].to_ndarray()[0]
-        water_vapour_mixing_ratio = (
-            self["water_vapour_mixing_ratio"][0]
-            - self.delta_liquid_water_mixing_ratio / 2
-        )
-
-        drho_dz = formulae.hydrostatics.drho_dz(
-            p=p,
-            T=T,
-            water_vapour_mixing_ratio=water_vapour_mixing_ratio,
-            lv=formulae.latent_heat_vapourisation.lv(T),
-            d_liquid_water_mixing_ratio__dz=(
-                self.delta_liquid_water_mixing_ratio / dz_dt / dt
-            ),
-        )
-        drhod_dz = drho_dz
-
-        self.particulator.backend.explicit_euler(self._tmp["z"], dt, dz_dt)
-        self.particulator.backend.explicit_euler(
-            self._tmp["rhod"], dt, dz_dt * drhod_dz
-        )
-
-        self.mesh.dv = formulae.trivia.volume_of_density_mass(
-            (self._tmp["rhod"][0] + self["rhod"][0]) / 2, self.mass_of_dry_air
-        )
+    def _compute_dz_dt(self, dt):
+        return -self.particulator.attributes["terminal velocity"].to_ndarray()[0]

examples/PySDM_examples/Loftus_and_Wordsworth_2021/planet.py

@@ -1,3 +1,10 @@
+"""
+Planetary properties used in calculations.
+
+Values are primarily taken from Table 1 of Loftus & Wordsworth (2021), unless otherwise noted.
+Each variable represents a physical property or atmospheric composition relevant for cloud microphysics modeling.
+"""
+
 from PySDM.physics.constants import si
 from dataclasses import dataclass
 from typing import Optional, Dict, Any
@@ -24,7 +31,7 @@ def to_dict(self) -> Dict[str, Any]:
 class EarthLike(Planet):
     g_std: float = 9.82 * si.metre / si.second**2
     T_STP: float = 300 * si.kelvin
-    p_STP: float = 1.01325 * 1e6 * si.pascal
+    p_STP: float = 1.01325 * 1e5 * si.Pa
     RH_zref: float = 0.75
     dry_molar_conc_H2: float = 0
     dry_molar_conc_He: float = 0
@@ -38,7 +45,7 @@ class EarthLike(Planet):
 class Earth(Planet):
     g_std: float = 9.82 * si.metre / si.second**2
     T_STP: float = 290 * si.kelvin
-    p_STP: float = 1.01325 * 1e6 * si.pascal
+    p_STP: float = 1.01325 * 1e5 * si.Pa
     RH_zref: float = 0.75
     dry_molar_conc_H2: float = 0
     dry_molar_conc_He: float = 0
@@ -52,7 +59,7 @@ class Earth(Planet):
 class EarlyMars(Planet):
     g_std: float = 3.71 * si.metre / si.second**2
     T_STP: float = 290 * si.kelvin
-    p_STP: float = 2 * 1e6 * si.pascal
+    p_STP: float = 2 * 1e5 * si.Pa
     RH_zref: float = 0.75
     dry_molar_conc_H2: float = 0
     dry_molar_conc_He: float = 0
@@ -66,7 +73,7 @@ class EarlyMars(Planet):
 class Jupiter(Planet):
     g_std: float = 24.84 * si.metre / si.second**2
     T_STP: float = 274 * si.kelvin
-    p_STP: float = 4.85 * 1e6 * si.pascal
+    p_STP: float = 4.85 * 1e5 * si.Pa
     RH_zref: float = 1
     dry_molar_conc_H2: float = 0.864
     dry_molar_conc_He: float = 0.136
@@ -80,7 +87,7 @@ class Jupiter(Planet):
 class Saturn(Planet):
     g_std: float = 10.47 * si.metre / si.second**2
     T_STP: float = 284 * si.kelvin
-    p_STP: float = 10.4 * 1e6 * si.pascal
+    p_STP: float = 10.4 * 1e5 * si.Pa
     RH_zref: float = 1
     dry_molar_conc_H2: float = 0.88
     dry_molar_conc_He: float = 0.12
@@ -94,7 +101,7 @@ class Saturn(Planet):
 class K2_18B(Planet):
     g_std: float = 12.44 * si.metre / si.second**2
     T_STP: float = 275 * si.kelvin
-    p_STP: float = 0.1 * 1e6 * si.pascal
+    p_STP: float = 0.1 * 1e5 * si.Pa
     RH_zref: float = 1
     dry_molar_conc_H2: float = 0.9
     dry_molar_conc_He: float = 0.1
@@ -108,7 +115,7 @@ class K2_18B(Planet):
 class CompositeTest(Planet):
     g_std: float = 9.82 * si.metre / si.second**2
     T_STP: float = 275 * si.kelvin
-    p_STP: float = 0.75 * 1e6 * si.pascal
+    p_STP: float = 0.75 * 1e5 * si.Pa
     RH_zref: float = 1
     dry_molar_conc_H2: float = 0.1
     dry_molar_conc_He: float = 0.1