Processed Data and Inversion Results for Constraining the Io Plasma Torus

The processed and used data for constraining the plasma torus.

FieldLines.txt are the mapped positions along the magnetic field lines calculated with the JRM33 model. The lines start at Io's orbit at 5.9 Jupiter Radii and are mapped towards the flattened Jupiter surface. The longitudinal resolution is 0.5°, resulting in 1440 total field lines, 720 for each the northern and the southern hemisphere. Therefore, the file contains of 1440 blocks, each introduced with the starting Easter System III longitude and the corresponding hemisphere. The block afterwards contains of 4 columns, three for the Cartesian position of the mapping and the last for the total field strength, which are formatted as

X[RJ], Y[RJ], Z[RJ], B[nT]

TravelTimesNorth.txt and TravelTimesSouth.txt contain the calculated travel times of the Alfven waves corresponding to the northern and southern Io Footprint (IFP), respectively. The travel times are calculated by using the observed positions of the IFP by Bonfond et al. (2017) and mapping along the magnetic field lines of the JRM33 model to Io's orbit. Then, the longitudinal distance to Io's position at the time of the observation is divided by Io's synodic orbital frequency. The file is formatted as

Lon[°], Travel Time [s], Error [s]

Lon is the system 3 eastern longitude of the footprint. Travel Time is the calculated travel time as described above and Error is the propagated uncertainty given by Bonfond et al. (2017)

Dipole.txt and Multipole.txt are the CSV inversion results. For N = 10000 randomly chosen scale heights (between 0.4 and 1.6 Jupiter radii [RJ]) and peak densities (between 500 and 3500 particles per cm³), the resulting misfit for a torus centered at the dipole or multipole centrifugal equator has been calculated, respectively. The files have 10000 CSV lines which are formatted as

Peak Density [1/cm³], Scale Height [RJ], Misfit

Peak Density is the maximum particle density at the center of the torus and Scale Height is the scale height H of the torus with the density profile decreasing with distance z to the center of the torus corresponding to

\(\rho = \rho_0 e^{-z^2 \over H^2}\)

本数据集为用于约束等离子体环（plasma torus）的经处理并投入研究使用的实验数据。

FieldLines.txt 存储了基于JRM33模型计算得到的磁场线映射位置。该系列磁场线起始于距木星5.9倍木星半径（RJ）的木卫一（Io）轨道，并向扁平化的木星表面进行映射。其纵向分辨率为0.5°，总计生成1440条磁场线，北半球与南半球各720条。因此该文件包含1440个数据块，每个数据块以起始的木星系第三系统东经及对应半球作为标识。每个数据块后续包含4列数据，前三列为映射结果的笛卡尔坐标系位置，最后一列为总磁场强度，格式如下：
X[RJ]、Y[RJ]、Z[RJ]、B[纳特斯拉（nT）]

TravelTimesNorth.txt与TravelTimesSouth.txt分别存储了对应北半球与南半球木卫一足迹（IFP）的阿尔文波（Alfvén waves）传播时间计算结果。该传播时间的计算基于Bonfond等人（2017年）观测得到的IFP位置，通过JRM33模型的磁场线映射至木卫一轨道后完成。随后将观测时刻木卫一位置的纵向距离除以木卫一的会合轨道频率，即可得到传播时间。文件格式如下：
经度[°]、传播时间[s]、误差[s]
其中经度为木卫一足迹的木星系第三系统东经；传播时间为前文所述的计算得到的传播时间；误差为Bonfond等人（2017年）给出的传递不确定度。

Dipole.txt与Multipole.txt为逗号分隔值（CSV）格式的反演结果文件。本次实验随机选取了10000组参数：尺度高度范围为0.4至1.6倍木星半径（RJ），峰值密度范围为500至3500粒子/立方厘米；分别针对以偶极离心赤道或多极离心赤道为中心的等离子体环，计算了对应的拟合残差。每个文件包含10000行CSV数据，格式如下：
峰值密度[1/cm³]、尺度高度[RJ]、拟合残差
其中峰值密度为等离子体环中心处的最大粒子密度，尺度高度为等离子体环的特征尺度H，其密度分布随到环中心的距离z的变化关系为：
(
ho =
ho_0 e^{-z^2 / H^2})