Forcing

This module contains the functions used for the evaluation of stellar forcing (insolation).

SWAMPE.forcing.Phieqfun(Phibar, DPhieq, lambdas, mus, I, J, g)

Evaluates the equilibrium geopotential from Perez-Becker and Showman (2013).

Parameters

param Phibar

Mean geopotential

type Phibar

float

param DPhieq

The difference between mean geopotential and the maximum geopotential

type DPhieq

float

param lambdas

Uniformly spaced longitudes of length I.

type lambdas

array of float

param mus

Array of Gaussian latitudes of length J.

type mus

array of float

param I

number of longitudes

type I

int

param J

number of latitudes.

type J

int

param g

Surface gravity, m/s^2.

type g

float

Returns

return PhieqMat

the equilibrium geopotential, array (J,I)

rtype

array of float

SWAMPE.forcing.Qfun(Phieq, Phi, Phibar, taurad)

Evaluates the radiative forcing on the geopotential. Corresponds to the Q from Perez-Becker and Showman (2013), but has an extra factor of g as we are evaluating the geopotential, and they are evaluating the geopotential height.

Parameters

param Phieq

Equilibrium geopotential, (J,I)

type Phieq

array of float64

param Phi

Geopotential with the mean subtracted, (J,I)

type Phi

array of float64

param Phibar

Mean geopotential

type Phibar

float64

param taurad

radiative time scale, s

type taurad

float64

Returns

return Q

Geopotential forcing, (J,I)

rtype

array of float64

SWAMPE.forcing.Qfun_with_rampup(Phieq, Phi, Phibar, taurad, t, dt)

Evaluates the radiative forcing on the geopotential, but slowly ramps up the forcing to improve stability for short radiative timescales.

Parameters

param Phieq

Equilibrium geopotential, (J,I)

type Phieq

array of float64

param Phi

Geopotential with the mean subtracted, (J,I)

type Phi

array of float64

param Phibar

Mean geopotential

type Phibar

float64

param taurad

radiative time scale, s

type taurad

float64

param t

number of current timestep

type t

int

param dt

timestep length

type dt

float64

Returns

return Q

Geopotential forcing, (J,I)

rtype

array of float64

SWAMPE.forcing.Rfun(U, V, Q, Phi, Phibar, taudrag)

Evaluates the first and second component of the vector that expresses the velocity forcing in Perez-Becker and Showman. The divergence and vorticity (F,G) correspond to the forcing on the state variables delta and zeta, respectively.

Parameters

param U

zonal velocity component, (J,I)

type U

array of float

param V

meridional velocity component, (J,I)

type V

array of float

param Q

radiative forcing of geopotential, (J,I)

type Q

array of float

param Phi

geopotential with the mean subtracted, (J,I)

type Phi

array of float

param Phibar

mean geopotential

type Phibar

float

param taudrag

drag timescale,in seconds

type taudrag

float

Returns

return
  • F

    Zonal component of the velocity forcing vector field

  • G

    Meridional component of the velocity forcing vector field

rtype

arrays of float (J,I)