Get the Venus plasma boundary positions

Here we will get the plasma boundaries the bow shock and induced magnetosphere boundaries (sometimes call also as magnetic pileup boundary or ion composition boundaries).

Author: Yoshifumi Futaana

Model from Venus Express, solar minimum

The model is based on Martinecz et al., 2008. (doi: 10.1016/j.pss.2007.07.007)

irfpy implementation to get the bow shock position

irfpy provides a function to get the boundary surface position.

https://irfpy.irf.se/projects/planets/api/api_irfpy.venus.bowshock.html

from irfpy.venus import bowshock

x_bs, r_bs = bowshock.xr_martinecz08()

x_bs and r_bs are numpy arrays that give the position of the bow shock in Rv.

import matplotlib.pyplot as plt

plt.plot(x_bs, r_bs, 'b')   # Plot the data in the cylindrical coordinate

# Figure decoration.
plt.xlim(2, -10)
plt.ylim(0, 7)
plt.xlabel('X [Rv]')
plt.ylabel('R [Rv]')
plt.gca().set_aspect(1)

irfpy implementation to get the IMB (ICB) position

https://irfpy.irf.se/projects/planets/api/api_irfpy.venus.icb.html

It is the same interface to get the bow shock position.

from irfpy.venus import icb

x_icb, r_icb = icb.xr_martinecz08()

plt.plot(x_icb, r_icb, 'r')   # Plot the data in the cylindrical coordinate

# Figure decoration.
plt.xlim(2, -10)
plt.ylim(0, 7)
plt.xlabel('X [Rv]')
plt.ylabel('R [Rv]')
plt.gca().set_aspect(1)

Final plot

Here is the final plot

from matplotlib.patches import Circle   # Circle to represent Venus

plt.plot(x_bs, r_bs, 'b')   # Plot the BS data in the cylindrical coordinate
plt.plot(x_icb, r_icb, 'r')   # Plot the ICB data in the cylindrical coordinate

# Figure decoration.
plt.gca().add_patch(Circle([0, 0], 1, color='y'))   # Add venus disk

plt.xlim(2, -10)
plt.ylim(0, 7)
plt.xlabel('X [Rv]')
plt.ylabel('R [Rv]')
plt.gca().set_aspect(1)