single_dispersionAddGasMicrowavesEarth

Workspace.single_dispersionAddGasMicrowavesEarth(self, single_dispersion: pyarts3.arts.Numeric | None = None, atm_point: pyarts3.arts.AtmPoint | None = None, k1: pyarts3.arts.Numeric | None = None, k2: pyarts3.arts.Numeric | None = None, k3: pyarts3.arts.Numeric | None = None) → None

Add microwave gas refractivity for an Earth-like atmosphere.

This is the non-dispersive Bevis et al. (1994) model used by ARTS 2. It depends on pressure, temperature, and the H2O volume-mixing ratio in atm_point. H2O is optional and a missing H2O entry gives the dry-air value.

The added value is \(n-1\), matching the convention consumed by ray_point_back_propagation_agenda with its RefractiveStepwise option. The expression is

\[n - 1 = \frac{k_1 (P-e) + (k_2 + k_3/T)e}{T},\]

where \(e\) is the water-vapour partial pressure. The default coefficients are adjusted for pressure in Pa.

This method contributes refractivity only. It does not add absorption to single_propmat or derivatives to single_dispersion_jac.

Authors: Patrick Eriksson, Richard Larsson

Parameters:

  • single_dispersion (Numeric, optional) – A dispersion at a single freq point. See single_dispersion, defaults to self.single_dispersion [INOUT]

  • atm_point (AtmPoint, optional) – An atmospheric point in ARTS. See atm_point, defaults to self.atm_point [IN]

  • k1 (Numeric, optional) – Dry-air coefficient [K/Pa]. Defaults to 7.76e-07 [IN]

  • k2 (Numeric, optional) – Water-vapour coefficient [K/Pa]. Defaults to 7.04e-07 [IN]

  • k3 (Numeric, optional) – Water-vapour coefficient [K^2/Pa]. Defaults to 0.003739 [IN]