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Table 1 MC fit-parameters for the MC of 17 March 2015 (starting day)

From: The first super geomagnetic storm of solar cycle 24: “The St. Patrick’s day event (17 March 2015)”

Starting time = 10:38 UT CA (%) = −3 %
ΔT = 13.0 h Δt = 15 min
V MC = 550 km/s β CA = 116°
2R o = 0.166 AU Check = −6.4 %
B o = 25.65 nT Φ o = 5.4 × 1020 Mx
H = + 1 right-handed J o = 4.0 μA km−2
θ A  = −63° and ϕ A  = 162° (GSE coordinates) I T = 8.3 × 108 A
χ R = 0.244 N = 54
Asf (%) = 9.7 % Q o = 3
  1. ΔT, duration of the MC encounter (i.e., ΔT = end time – start time of MC passage); V MC, average solar wind speed (in km s−1) within the MC; 2R o, estimated diameter (in AU), where R O is the model-estimated radius; B O, estimated axial magnetic field magnitude (in nT); H, Handedness (+1 for right-handed or −1 for left-handed); ϕ A , θ A , longitude and latitude, respectively, of the MC axis (GSE coordinates); t o, estimated center time of the MC; χ R, square root of the reduced Chi-squared of the MC fit; asf(%), asymmetry factor (in %), which depends on t o and ΔT; CA (%), estimated relative closest approach distance, i.e., y o/R o (in %) where y o is closest approach; Φ o, estimated axial magnetic flux (in 1020 Mx); J O, estimated total axial current density (in μA km−2); Δt, length of the averages used in the analysis; these are usually 15, 30 min, or 1 h; β CA, cone angle, the angle between the MC axis and the X-axis (in GSE coordinates); “Check,” a check of the estimated radius by using duration, speed, CA, cone angle, and R o; I T , estimated total axial current (in 108 A); N, number of points used in the MC-fitting interval; Q o, estimated quality of the model fitting (where Q o = 1, 2, or 3, for excellent, good, or poor, respectively)