Statistical Comparison of Various Dayside Magnetopause Reconnection X-line Prediction Models

Ramiz A. Qudsi,   Brian Walsh, J. Broll, Stein Haaland

Boston University,   Los Alamos National Lab, Max-Planck Institute

*(qudsira@bu.edu)

(https://qudsiramiz.github.io)

                                                                                     1, *                                           1                         2                                                    3

                                       1                                               2                                                              3

Outline:

  • Region of interest
  • Location of x-line
    • Different models
  • Data
  • Results
  • Discussions

Qudsi (qudsira@bu.edu)

The BASICS

Qudsi (qudsira@bu.edu)

Source: NASA

Qudsi (qudsira@bu.edu)

Region of interest:

Qudsi (qudsira@bu.edu)

[Broll et al., 2017]

Source: wikipedia

Qudsi (qudsira@bu.edu)

Location of x-line: Models

Local field bisection [Moore et al., 2002]

Maximum exhaust speed  [Swisdak and Drake, 2007]

Maximum magnetic shear [Trattner et al., 2007]

Maximum reconnecting field energy [Hesse et al., 2013]

Qudsi (qudsira@bu.edu)

Magnetic shear [Trattner et al., 2007]:

\cos(\theta) = \left(\textbf{B}_{\rm sh} \cdot \textbf{B}_{\rm msp}\right)/ \left(|\textbf{B}_{\rm sh}| |\textbf{B}_{\rm msp}|\right)
B_{\rm rec} = |\textbf{B}_{\rm msp} \cdot \textbf{i}_{\rm xn}|

Local field bisection [Moore et al., 2002]:

Reconnection field energy [Hesse et al., 2013]:

E \propto \left(B_{\rm sh}^2 \times B_{\rm msp}^2\right)

Exhaust speed [Swisdak and Drake, 2007]:

V_{\rm A} = \left[\frac{B_{\rm sh} B_{\rm msp} \left(B_{\rm sh} + B_{\rm msp}\right)}{\left(n_{\rm p,msp}B_{\rm sh} + n_{\rm p,sh}B_{\rm msp}\right)} \right]^{1/2}

sh: magnetosheath

msp: magnetosphere

Location of x-line: Models

Qudsi (qudsira@bu.edu)

DATA

Qudsi (qudsira@bu.edu)

Data:

Solar

Wind

OMNI

Cooling-2001 Model

Magnetosheath

Magnetopause

Shue-1998 Model

T-96 and IGRF Model

Magnetospheric Fields

Qudsi (qudsira@bu.edu)

Data

Solar Wind data: OMNI (propagated to the magnetopause)

Magnetosheath data: MMS (FPI and FGM)

Magnetospheric magnetic field: Models (T96 or T05 and IGRF)

Magnetosheath magnetic field: Models (Cooling model)

x

z

y

GSM coordinate system

Qudsi                                                                Center for Space Physics, BU                                                 qudsira@bu.edu

Methodology

Qudsi (qudsira@bu.edu)

Methodology

  • Look at the instances when MMS observed a jet reversal while crossing the magnetopause.

Qudsi (qudsira@bu.edu)

Magnetosheath

Magnetosphere

[Broll et al., 2017]

Qudsi (qudsira@bu.edu)

Methodology

  • For the observed parameters of IMF, Magnetosheath and Magnetosphere and Magnetopause find the model predicted x-line locations.
  • Find the distance of x-line from MMS, along the magnetopause, for different models.
  • Look at the statistical distribution of distances (histogram etc.) for different models.

Qudsi (qudsira@bu.edu)

  • Look at the instances when MMS observed a jet reversal while crossing the magnetopause.
\left< \Delta V_{L} \right> = \pm 70 km/s

RESULTS

Qudsi (qudsira@bu.edu)

The maximum shear model:

The maximum exhaust velocity model

Qudsi (qudsira@bu.edu)

B_z \gt 0
B_z \lt 0

DISCUSSIONS

Qudsi (qudsira@bu.edu)

Discussions:

For negative z-component of IMF, reconnection energy and bisection field models both give very similar statistics.

For positive z-component, shear and bisection model seem to do the best job of predicting the expected x-line

Statistically, bisection field model seem to perform better than other models for different IMF and magnetopause conditions.

Qudsi (qudsira@bu.edu)

Thank You!

Link to the presentation

Qudsi (qudsira@bu.edu)

Made with Slides.com