Active regions and the find_jz_V2 program


  • Search list for halo or partial halo CME occuring some four days before magnetic cloud event.
  • Search YOHKOH SXT files for corresponding eruption and identify the active region.
  • Obtain available vector magnetogram data for the active regions near the times of eruption.
  • Plot SOHO MDI data over YOHKOH SXT image for each active region.
  • Outline the appropriate contours to make calculations using Keith Lambkin's find_jz_V2 program.
  • From the program output we calculate the current and magnetic flux of the active region.

[YOHKOH SXT & SOHO MDI] [find_jz_V2 window]



find_jz_V2


     The find_jz_V2 program uses HSP vector magnetogram data to make line of sight calculations of current and magnetic flux. In calculating magnetic flux, the program integrates the line of sight component of the magnetic field over the chosen area. From the equation Ñ×(B) = μ0J, it is clear that line of sight component of the current density can be calculated from the two magnetic field components in the plane of the sun's surface. From here the program integrates over the line of sight component of the current density for the chosen area.




Active Regions


Calculations from find_jz_V2, α from Zack Holder
YearErupt. TimeM'gram TimeARIAR (A)ΦAR (Wb)L (km)αAR (m-1)I(%)Φ(%)
1995Feb 04 16:02Feb 04 01:5178342.28E+122.02E+1342236N/A0523
Feb 28 08:46Feb 27 03:1378461.88E+121.45E+136664N/A0522
Feb 28 19:4578463.39E+123.94E+1361304N/A0308
Dec 11 02:24Dec 10 17:2279301.94E+121.04E+1335470N/A11178
Dec 11 17:1579301.56E+121.38E+1334035N/A14134
1.10E+121.10E+1333215N/A20169
1997Jul 30 04:45July 28 19:4880661.85E+129.57E+1233420N/A0637
1.70E+128.53E+1233420N/A0742
1998Feb 14 07:00Feb 12 17:3381562.28E+123.69E+1344082-1.23E-080824
Apr 29 16:58Apr 28 16:3882103.14E+123.78E+13606891.72E-080642
Apr 29 16:3982102.25E+123.71E+13299342.70E-080943
1999Feb 14 11:16Feb 11 19:2684572.92E+125.38E+1362329-4.66E-091153
Aug 04 22:13Aug 02 16:3686511.05E+131.91E+1490213-7.49E-090205
Sept 18 15:12Sept 20 17:0087002.12E+122.93E+1370120-5.38E-090303
2000Jul 14 09:27July 11 16:5290775.43E+127.26E+13N/A-4.84E-081363
July 14 16:3990776.52E+128.04E+1365610-5.29E-081157
July 17 16:3290771.66E+123.06E+1334855-2.92E-0843149
Jul 25 03:58July 21 20:2890974.75E+128.84E+1357819N/A0306
Jul 27 22:18July 26 16:3390975.00E+125.01E+13533081.69E-080656
July 28 16:4090971.39E+122.10E+1341416-1.75E-0820133
Aug 09 17:02Aug 08 16:3791142.51E+124.13E+1384062-1.27E-081660
Aug 11 16:5891142.94E+125.24E+1377911-9.75E-091447



Flux ratio vs. current ratio


[Flux vs. Current]

*Standard Deviation (σ) calculated from Zack Holder's list of Active Region currents and magnetic fluxes.

*Shapes correspond with 1σ (Diamond), 2σ (Triangle), and 3σ (Square) given by the find_jz_V2 program.

*Colors correspond with best fit, good fit, and worst fit given by the cloud_fit program.




Additional Results


Amount of twist and orientation, AR vs. MC
YearErupt. TimeM'gram TimeARαL (AR)αL (MC), L=3AU# turnsAR TiltMC θ0
1995Feb 04 16:02Feb 04 01:517834N/A-63.8910.2-30-18
Feb 28 08:46Feb 27 03:137846N/A-74.6811.945-55
Feb 28 19:457846N/A-74.6811.9-6-55
Dec 11 02:24Dec 10 17:227930N/A-30.924.9-1739
Dec 11 17:157930N/A-30.924.9-3339
N/A-30.924.9-3339
1997Jul 30 04:45July 28 19:488066N/A83.5113.3-17-3
N/A83.5113.3-17-3
1998Feb 14 07:00Feb 12 17:338156-0.54255.528.8-5-5
Apr 29 16:58Apr 28 16:3882101.04431.565.079-9
Apr 29 16:3982100.80831.565.0-20-9
1999Feb 14 11:16Feb 11 19:268457-0.290-29.964.829-9
Aug 04 22:13Aug 02 16:368651-0.676-45.137.2-2941
Sept 18 15:12Sept 20 17:008700-0.377-149.7923.8-1559
2000Jul 14 09:27July 11 16:529077N/A101.0016.1N/A6
July 14 16:399077-3.471101.0016.1102
July 17 16:329077-1.018101.0016.1-752
Jul 25 03:58July 21 20:289097N/A-64.6710.3175
Jul 27 22:18July 26 16:3390970.901-25.934.1295
July 28 16:409097-0.725-25.934.16318
Aug 09 17:02Aug 08 16:379114-1.06842.256.7018
Aug 11 16:589114-0.76042.256.783-11



[Orientation AR vs. MC]

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