Dynamics

中文

Pointwise only: Coriolis parameter and hydrostatic ω ↔ w. No grid advection, spherical harmonics, or finite differences.

coriolis_parameter

f = 2 Ω sin φ with Ω = 7.292×10⁻⁵ rad s⁻¹. Result in s⁻¹. Equator is 0; 45° is about 1.031×10⁻⁴.

import pymeteo as pm
pm.coriolis_parameter(35.0)
pm.coriolis_parameter(45.0)

NCL name: pymeteo.ncl.coriolis_param(lat) — degrees in, s⁻¹ out.

omega_to_w

Pressure-coordinate vertical velocity to geometric w:

w = −ω / (ρ g), ρ = p / (Rd T)

Rd = 287.058 J K⁻¹ kg⁻¹, g = 9.80665 m s⁻². Positive ω (subsidence) gives negative w.

Modern argument order is (omega, temperature, pressure). The NCL shim is (omega, p, t) — see NCL.

omega_unit default Pa/s; hPa/s is accepted. Temperature default C, pressure default hPa.

pm.omega_to_w(0.1, 0.0, 850.0)

w_to_omega

The inverse: ω = −ρ g w. Same modern order (w, temperature, pressure).