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)