Notes

Data

updated_events_JNO_method=fit_tau=0:01:00_ts=0:00:01.arrow and events.JNO.fit.ts_1.00s_tau_60s.arrow are the same data for backward compatibility.

updated_events_Wind_tr=20110825-20160630_method=fit_tau=0:01:00_ts=0:00:00.090909.arrow and events.Wind.fit.ts_0.09s_tau_60s.arrow

Notation

Data Level

• l0: unprocessed

• l1: cleaned data, fill null value, add useful columns

• l2: time-averaged data

Columns naming conventions

• v_{x,y,z} or sw_vel_{X,Y,Z}: solar wind plasma speed in the ANY coordinate system, in units of \(km/s\)

  • sw_vel_{r,t,n}: solar wind plasma speed in the RTN coordinate system, in units of \(km/s\)
  • sw_vel_gse_{x,y,z}: solar wind plasma speed in the GSE coordinate system, in units of \(km/s\)
  • sw_vel_lmn_{x,y,z}: solar wind plasma speed in the LMN coordinate system, in units of \(km/s\)
    • v_l or sw_vel_l: abbreviation for sw_vel_lmn_1
    • v_mn or sw_vel_mn (deprecated)

• radial_distance: radial distance of the spacecraft, in units of \(AU\)

• sw_elevation: solar wind elevation angle, in units of \(\degree\)

• sw_azimuth: solar wind azimuth angle, in units of \(\degree\)

• b_rtn_{x,y,z} or b_{r,t,n}: magnetic field in the RTN coordinate system

• b_gse_{x,y,z}: magnetic field in the GSE coordinate system

• model_b_{r,t,n}: modelled magnetic field in the RTN coordinate system

• state : 1 for solar wind, 0 for non-solar wind

Updates

09/23/2024

Wind

Figure 1: Distribution of daily averages of DD per day over v with the fit of an linear function.

03/15/2024

Discontinuities in log-log scale

Same as above but with multiple time resolutions and time windows

02/27/2024

Evolution of plamsa property using fitting method

Evolution of plamsa property using derivative method

Figure 2: From top to bottom is Juno observation in 1,2,3,4,5 AU

02/22/2024

First Year

Last Year

02/20/2024

02/19/2024

02/18/2024

Thickness

Current Density

02/17/2024

New Fit Width

New

Old

Wind

Juno

Derivative method

Fit method

Solar Wind Model

Sadly, JUNO does not provide plasma data during the cruise phase, so to estimate the plasma state we will use MHD model.

We are using Michigan Solar WInd Model 2D (MSWIM2D), which models the solar wind propagation in 2D using the BATSRUS MHD solver. Keebler et al. (2022)

Some key points about the model

• Representing the solar wind in the ecliptic plane from 1 to 75 AU
• 2D MHD model, using the BATSRUS MHD solver
• Inclusion of neutral hydrogen (important for the outer heliosphere)
• Inner boundary is filled by time-shifting in situ data from multiple spacecraft

For model validation part, please see JUNO Model Report.

TODOs

Science part

• Analysis

  • Re-calculate the occurrence rate of IDs

  • Distribution of \(δB/B\) over radius (related to the alfvenicity, identification standard about neighboring fluctuations)

  • \(\theta_{n,v}\) distribution

  • Correlation between plasma beta and thickness / current density

  • Check Datagap

  • Check ARTEMIS-B data in different states (solar wind, magnetosheath, magnetotail, moon wake)

  • Distribution of |B| over radius

  • JUNO from 2012-09~2012-10 lack of IDS and extreme large thickness

  • Wind data

  • Add error bar

  • Validate the effects of calibrate candidate duration

  • Contribution of discontinuities to the power spectrum

  • Validate model density with Voyager

• Identifaction
  • Ensemble forest?
  • Smoothing is important?
  • Check change point algorithm
• Visualize data gaps
• Features
  • Thickness in N direction
  • Use high resolution data for feature extraction
• Compare with other methods of identifying IDs
  • Verify with other methods of identifying IDs
• Incorporate solar wind propagation model
  • Verify with solar wind propagation model
    • Coordinate transformation

Archived Figures

Figure 3: a, Current density of IDs as a function of the radial distance from the Sun. b, Current density of IDs normalized to the Alfven current as a function of the radial distance from the Sun.

Figure 4: a, Thickness of IDs as a function of the radial distance from the Sun. b, Thickness of IDs normalized to the ion inertial length as a function of the radial distance from the Sun.

References

Keebler, Timothy B., Gábor Tóth, Bertalan Zieger, and Merav Opher. 2022. “MSWIM2D: Two-Dimensional Outer Heliosphere Solar Wind Modeling.” Astrophysical Journal Supplement Series 260 (2): 43. https://doi.org/10.3847/1538-4365/ac67eb.