This repository contains MATLAB code for the Connerney et al. (2020) Jupiter current sheet model. Please see https://github.com/marissav06/con2020_idl for the IDL version and https://github.com/gabbyprovan/con2020/ for Python (Python 3).
A PDF documentation file (con2020_final_code_documentation_sept13_2021.pdf) is available in this repository. It describes the Connerney current sheet model and general code development (equations used, numerical integration assumptions, accuracy testing, etc.). Details specific to the MATLAB code are provided in this readme file.
These codes were developed by Fran Bagenal, Marty Brennan, Matt James, Gabby Provan, Marissa Vogt, and Rob Wilson, with thanks to Jack Connerney and Masafumi Imai. They are intended for use by the Juno science team and other members of the planetary magnetospheres community. Our contact information is in the documentation PDF file.
- Obtain the default model parameters: params = con2020_model_rtp('default_values')
- Edit the structure to adjust the model parameters as you wish, e.g. params.r1__outer_rj = 50.0 (sets outer edge to 50 Rj; default is 51.4 Rj)
- Call the function with the adjusted parameter structure: B = con2020_model_rtp(eq_type, r_rj, colat_rads, elong_rads, params)
- eq_type - Whether to use the integral or analytic versions of the model equations. Options are 'integral', 'analytic' or 'hybrid', or set to 'default_values' to return a structure of all default values.
- Position - format depends on whether user is running con2020_model_rtp or con2020_model_xyz
- For spherical input:
- r_rj - radial distance, in Rj. Value(s) must be 0 < r_rj < 200.
- colat_rads - colatitude, in radians. Value(s) must be 0 <= colat_rads <= pi.
- elong_rads - East longitude, right handed, in radians. Value(s) must be 0 <= elong_rads <= 2pi.
- For cartesian input:
- x_rj - SYSIII x position, in Rj, Values must be -200 < x_rj < 200.
- y_rj - SYSIII y position, in Rj, Values must be -200 < x_rj < 200.
- z_rj - SYSIII z position, in Rj, Values must be -200 < x_rj < 200.
- Note: for spherical input, r_rj, colat_rads and elong_rads can be scalars or 1D arrays (nx1), but only one eq_type. For cartesian input, x_rj, y_rj and z_rj can be scalars or 1D arrays (nx1), but only one eq_type.
- For spherical input:
| Variable name | Description | Default value |
|---|---|---|
| mu_i_div2__current_density_nT | mu0i0/2 term (current sheet current density) | 139.6 nT |
| i_rho__radial_current_intensity_MA | radial current term from Connerney et al., 2020 (set this to zero to turn radial currents off as in Connerney et al. 1981) | 16.7 MA |
| r0__inner_rj | inner edge of current disk in Rj | 7.8 Rj |
| r1__outer_rj | outer edge of current disk in Rj | 51.4 Rj |
| d__cs_half_thickness_rj | D, current sheet half thickness | 3.6 Rj |
| xt__cs_tilt_degs | current sheet tilt angle | 9.3 degrees |
| xp__cs_rhs_azimuthal_angle_of_tilt_degs | azimuthal angle of the current sheet tilt (right handed) | 155.8 degrees right handed (corresponds to 204.2 degrees left handed longitude) |
| error_check | 1 to check that inputs are valid (Default), or set to 0 to skip input checks (faster) | 1 |
- The code outputs a vector that contains the 3 components of the magnetic field produced by the current sheet, in SIII right-handed.
- For con2020_model_rtp (spherical input/output) the vector is [Br, Btheta, Bphi] in nT.
- For con2020_model_xyz (cartesian input/output) the vector is [Bx, By, Bz] in nT.
References:
- Connerney, J. E. P., Acuña, M. H., & Ness, N. F. (1981). Modeling the Jovian current sheet and inner magnetosphere. Journal of Geophysical Research, 86, 8370-8384. https://doi.org/10.1029/JA086iA10p08370
- Connerney, J. E. P., Timmins, S., Herceg, M., & Joergensen, J. L. (2020). A Jovian magnetodisc model for the Juno era. Journal of Geophysical Research: Space Physics, 125, e2020JA028138. https://doi.org/10.1029/2020JA028138
- Edwards, T. M., Bunce, E. J., & Cowley, S. W. H. (2001). A note on the vector potential of Connerney et al.'s model of the equatorial current sheet in Jupiter's magnetosphere. Planetary and Space Science, 49, 1115– 1123. https://doi.org/10.1016/S0032-0633(00)00164-1