PyGCPM 0.1.0

Python wrapper for the Global Core Plasma Model

PyGCPM

PyGCPM is a Python 3 wrapper for the Global Core Plasma Model (Gallagher et al., 2000). This module uses version 2.4 from https://plasmasphere.nasa.gov/models/

The original code has been modified slightly such that it produces less output to the terminal and the path of the data files used is passed through a C wrapper so that the Fortran code is able to find them.

It's also worth noting that the IGRF component of the model needs updating - strange things may happen with years beyond ~2010. I will fix this.

Installation

Using pip:

python3 -m pip install PyGCPM --user

or,

pip3 install PyGCPM --user

From this repo:

git clone https://github.com/mattkjames7/PyGCPM.git
cd PyGCPM/
python3 setup.py install --user

Usage

So far, there are only two working functions - GCPM and PlotEqSlice, the PlotMLTSlice function is doing odd things. It's worth noting that this model will take some time to run with large numbers of points.

GCPM

This function takes in position in the Solar Magnetospheric (SM) coordinate system, along with a date and a time then produces a model output for each position.

import PyGCPM
ne,nH,nHe,nO = PyGCPM.GCPM(x,y,z,Date,ut,Kp=Kp,Verbose=Verbose)

Where the inputs are:

Variable	Data Type	Description
x	float or numpy.ndarray	Scalar or array x position(s) in RE
y	float or numpy.ndarray	Scalar or array y position(s) in RE
z	float or numpy.ndarray	Scalar or array z position(s) in RE
Date	int or numpy.ndarray	Integer date in format yyyymmdd - if provided with a scalar then all positions will use the same date, otherwise an array can be provided for a time series
ut	float or numpy.ndarray	Floating point hours where ut = hh + mm/60 + ss/3600. As with Date - if provided with a scalar then all positions will use the same time, otherwise an array can be provided for a time series
Kp	float or numpy.ndarray	(optional) Kp index, as with Date and ut - this can be a scalar or an array
Verbose	bool	(optional) If True then the function will display its progress in the terminal

Function outputs:

Variable	Data Type	Description
ne	float32	Electron density at each position (cm-3)
nH	float32	Proton density at each position (cm-3)
nHe	float32	Helium ion density at each position (cm-3)
nO	float32	Oxygen ion density at each position (cm-3)

PlotEqSlice

This function will plot a slice through the SM equator (z_SM = 0).

import PyGCPM
PyGCPM.PlotEqSlice(Date,ut,Parameter='ne',Rmax=10.0,dR=0.5,Kp=1.0,fig=None,
		maps=[1,1,0,0],zlog=True,cmap='gnuplot',scale=None,Verbose=False)

Variable	Data Type	Description
Date	int	Integer date in format yyyymmdd
ut	float	Floating point hours where ut = hh + mm/60 + ss/3600
Parameter	str	String containing the name of the parameter to plot: `'ne'
Rmax	float	This defines the maximum postion along x and y axes to calculate the model at - the x and y limits of the plot are (-Rmax,Rmax) and (Rmax,-Rmax), respectively
dR	float	The plot is a grid - this is the size of a grid box in RE
Kp	float	Kp index
fig	object or None	If None - a new plot is created; if set to an instance of matplotlib.pyplot, then the current figure is used and a new subplot is created within; if a matplotlib.pyplot.Axes instance is used then plotting is done on the current axes
maps	list or tuple	This defines the number of subplots and the position of the current plot: maps = [xmaps,ymaps,xmap,ymap]
zlog	bool	If True, the color scale is logarithmic
cmap	str	String containing the name of the colormap to use (alternatively provide the colormap object itself)
scale	list, tuple or None	If None then the limits of the color scale are detemined automatically. If list or tuple then these should contain two elements defining the minimum and maximum scale limits.
Verbose	bool	If True then the function will display its progress in the terminal

References

Gallagher, D. L., Craven, P. D., & Comfort, R. H. (2000, aug). Global core plasma model. J. Geophys. Res. Sp. Phys., 105(A8), 18819–18833. doi: 10.1029/1999JA000241