a t y lui, d. g. sibeck, t. phan, v. angelopoulos, k.-h. glassmeier, j. mcfadden, c. carlson, d....
TRANSCRIPT
A T Y Lui, D. G. Sibeck, T. Phan, V. Angelopoulos, K.-H. Glassmeier, J. McFadden, C. Carlson, D. Larson, J. Bonnell, + …
Outline Previous:
Reconstruction based on solving Grad-Shafranov equation
Benchmarking of procedure
Results of reconstruction for magnetic flux rope seen by Themis. Present:
Comparison between model and observed parameters
Current density and structure from each Themis satellite.
Reconstruction of plasma configurationfrom Themis observations
Progress Report
Magnetic flux rope on 2007 May 20 found by David Sibeck
The plasma structures seen by Themis A and E are quite similar.
Observed Structure from Themis S/C10
-1
100
101
-200
-100
0
100
300
200
100
0
-100200
100
0
20
10
-10
0
10
20
0
-2020
10
0
-10
21:50 21:55 22:00 22:05 22:10 22:15 22:20
2007 May 20 THEMIS-A/ESA/FGM
UTXgsm (R E)Ygsm (R E)Zgsm (R E)
-7.5 10.6 6.3
-7.7 10.4 6.2
10-1
100
-200
-100
0
100
200
0
200
100
0
-100
30
20
10
020
10
0
-10
-20
-10
0
10
20
10
0
21:50 21:55 22:00 22:05 22:10 22:15 22:20
2007 May 20 THEMIS-B/ESA/FGM
UTXgsm (R E)Ygsm (R E)Zgsm (R E)
-8.1 9.7 5.6
-8.1 9.5 5.4
10-1
100
101
-200
-100
0
100
200
0
200
100
0
-10040
30
20
1020
10
0
-10
-20
0
20
20
10
0
-10
21:50 21:55 22:00 22:05 22:10 22:15 22:20
2007 May 20 THEMIS-C/ESA/FGM
UTXgsm (R E)Ygsm (R E)Zgsm (R E)
-8.1 9.8 5.6
-8.2 9.6 5.5
10-1
100
-200
0
200
300
200
100
0
200
0
40
20
-20
0
-20
-10
0
10
40
20
0
21:50 21:55 22:00 22:05 22:10 22:15 22:20
2007 May 20 THEMIS-D/ESA/FGM
UTXgsm (R E)Ygsm (R E)Zgsm (R E)
-7.9 10.1 5.8
-8 9.8 5.7
10-1
100
101
-200
-100
0
100
200
100
0
200
100
0
-10030
20
10
-20
-10
0
10
20
10
0
-10
-2020
10
0
-10
21:50 21:55 22:00 22:05 22:10 22:15 22:20
2007 May 20 THEMIS-E/ESA/FGM
UTXgsm (R E)Ygsm (R E)Zgsm (R E)
-7.7 10.5 6.2
-7.8 10.3 6
A B C
D E
Magnetic Field Strength ContoursFrom David Sibeck
10 nT contours
Red high,
Blue low
13.0
12.5
12.0
11.5
11.0
10.5
10.0
8.0 7.5 7.0 6.5 6.0 5.5 5.0
X (RE)
Magnetosphere
Magnetosheath
30 nT
20 nT
13.0
12.5
12.0
11.5
11.0
10.5
10.0
8.0 7.5 7.0 6.5 6.0 5.5 5.0
X (RE)
A
E
D
C
B
Bx, By
Vector Potential
Themis B
Themis C
Themis D
Themis E
-500
0
500
22:00 22:01 22:02 22:03 22:04 22:05 22:06
2007 May 20 THEMIS B A1.0
0.8
0.6
0.4
0.2
0.0
-500
0
500
22:00 22:01 22:02 22:03 22:04 22:05 22:06
2007 May 20 THEMIS C A1.0
0.8
0.6
0.4
0.2
0.0
-500
0
500
22:00 22:01 22:02 22:03 22:04 22:05 22:06
2007 May 20 THEMIS D A
-1.0
-0.5
0.0
-500
0
500
22:00 22:01 22:02 22:03 22:04 22:05 22:06
2007 May 20 THEMIS E A
-0.8
-0.6
-0.4
-0.2
0.0
Comparison of plasma parameters between the model and observed values along the satellite track - red lines denote model values and black lines denote observed values.
Comparison of Plasma Parameters-1
30
25
20
15
22:00 22:01 22:02 22:03 22:04 22:05
-20
-15
-10
-5
20
16
12
8
2007 May 20 Themis BObservedModel
0.4
0.3
0.2
0.1
0.4
0.3
0.2
0.1
30
25
20
15
10
22:00 22:01 22:02 22:03 22:04 22:05
-25
-20
-15
-10
-5
15
10
5
0
2007 May 20 Themis C ObservedModel
0.5
0.4
0.3
0.2
0.1
0.4
0.3
0.2
0.1
40
20
0
22:00 22:01 22:02 22:03 22:04 22:05
10
0
-10
-30
-20
-10
0
10
2007 May 20 Themis D ObservedModel
1.2
1.0
0.8
0.6
0.4
0.2
0.4
0.3
0.2
0.1
-20
-15
-10
-5
22:00 22:01 22:02 22:03 22:04 22:05
20
15
10
5
-20
-15
-10
-5
2007 May 20 Themis E ObservedModel
0.60
0.50
0.40
0.30
0.50
0.40
0.30
0.20
Themis B Themis C Themis D Themis E
Quantitative comparison of magnetic field components between the model and observed values along the satellite track - black, red, and blue symbols denote x-, y-, and z-components, respectively.
The extremely good agreement is reflected by the correlation coefficients between observed and model values ranging from 0.9978 to 0.9998.
Comparison of Plasma Parameters-2
Themis B Themis C Themis D Themis E
-40
-20
0
20
40
-40 -20 0 20 40
Observed B Components (nT)
cc = 0.9998
Bx By Bz Curve Fit
2007 May 20 Themis B
-40
-20
0
20
40
-40 -20 0 20 40
Observed B Components (nT)
cc = 0.9996
Bx By Bz Curve Fit
2007 May 20 Themis C
-40
-20
0
20
40
-40 -20 0 20 40
Observed B Components (nT)
cc = 0.9978
Bx By Bz Curve Fit
2007 May 20 Themis D
-40
-20
0
20
40
-40 -20 0 20 40
Observed B Components (nT)
cc = 0.9988
Bx By Bz Curve Fit
2007 May 20 Themis E
Themis D
Parameters From Reconstruction - 1The current density is derived from curl B calculation using the 2D approximation:
The normalized magnetic field vector along the satellite track on the XY-plane is shown by the arrow in the Bz panel.
€
∂ /∂z <<∂ /∂x,∂ /∂y-500
0
500
40
20
0
-20-500
0
500
-500
0
500
0.6
0.4
0.2
-500
0
500
-500
0
500
-40
-20
0
20
40
-500
0
500
-500
0
500
-500
0
500
22:01:30 22:01:45 22:02:00 22:02:15 22:02:30 22:02:45 22:03:00
2007 May 20 THEMIS D
B (nT)
J (nA/m2)
P (nPa)
Bx
By
Bz
Jx
Jy
Jz
Pt
Pr
Themis C
Parameters From Reconstruction - 2
A stronger Bz region is located in the positive y-direction.Current density in the y-direction is quite strong, comparable to that along the z-direction.
-500
0
500
20
0-500
0
500
-500
0
500
0.8
0.6
0.4
0.2
-500
0
500
-500
0
500
10
0
-10-500
0
500
-500
0
500
-500
0
500
22:01:30 22:01:45 22:02:00 22:02:15 22:02:30 22:02:45 22:03:00
2007 May 20 THEMIS C
B (nT)
J (nA/m2)
P (nPa)
Bx
By
Bz
Jx
Jy
Jz
Pt
Pr
Themis B
Parameters From Reconstruction - 3
Strong and weak Bz regions are present in the positive y-direction. Weak Bz region is located in the negative y-direction.Current densities on the XY-plane are quite strong in comparison with that in the z-direction.
-500
0
500
20
0
-20-500
0
500
-500
0
500
0.6
0.4
0.2
-500
0
500
-500
0
500
-20
0
20
-500
0
500
-500
0
500
-500
0
500
22:01:30 22:01:45 22:02:00 22:02:15 22:02:30 22:02:45 22:03:00
2007 May 20 THEMIS B
B (nT)
J (nA/m2)
P (nPa)
Bx
By
Bz
Jx
Jy
Jz
Pt
Pr
Themis E
Parameters From Reconstruction - 4
Magnetic field and current density patterns are quite structured in general because Themis E was mainly in the magnetosheath region.
-500
0
500
20
0
-20
-500
0
500
-500
0
500
0.4
0.2
-500
0
500
-500
0
500
10
0
-10-500
0
500
-500
0
500
-500
0
500
22:01:30 22:01:45 22:02:00 22:02:15 22:02:30 22:02:45 22:03:00
2007 May 20 THEMIS E
B (nT)
J (nA/m2)
P (nPa)
Bx
By
Bz
Jx
Jy
Jz
Pt
Pr