Assume the axial symmetric CR density distribution with the minimum along with the axis of a cylinder Then the observed –G points toward the density minimum ( ) located on the axis Assume the cylinder moving with the average solar wind velocity V sw Then the velocity V ax representing the cylinder orientation can be deduced from the apparent velocity V app, as V ax = V app - V sw model (1) V sw V ax sun V app earth -G cylinder axis density min.
model (2) earth -G R λ cylinder axis RERE density min. Assume the gaussian distribution for CR density, as R : distance from the cylinder axis I 0 : minimum density, : radial scale of the cylinder Then G(R E ) observed at the earth (R= R E ) is… R E : minimum distance between the earth & the cylinder axis (1) (2) With the observed G(R E ), R E can be calculated from (2) for each set of parameters, I 0 & Find a set of I 0 & giving the best-fit G(R E ) to the observed gradient
Two CME events in 2001analyzed 35 directions (Nagoya-Japan, Hobart-Australia, SaoMartinho- Brazil) Prototype Muon network Onset time of SSC Max. K p FD size Corresponding CME Associated X-ray flare Onset timeSizeLocation 4/11 13: % 4/10 05:30X S, 9 W 8/27 19: % 8/25 16:50X S, 34 E CR data used S.Watari 2002
Observation 4/118/27 ρGx ρGy ρGz
Results for Apr. 11 event cylinder orientation : = 50.2 = -5.2 passed the earth at R E = AU best-fit parameters : I 0 = % = AU averages over the best-fit period: Vsw = 696 km/s B = 21.2 nT = AU
cylinder orientation : = 66.4 = Passed the earth at R E = AU best-fit parameters : I 0 = % = AU Results for Aug. 27 CME averages over the best-fit period: Vsw = 533 km/s B = 7.4 nT = 0.15 AU
Density profiles Apr. 11 CMEAug. 27 CME
Results for Apr. 11 event by NM cylinder orientation : = = 15.7 passed the earth at R E = AU best-fit parameters : I 0 = % = AU averages over the best-fit period: Vsw = 696 km/s B = 21.2 nT = AU
cylinder orientation : = 57.9 = Passed the earth at R E = AU best-fit parameters : I 0 = % = AU Results for Aug. 27 CME by NM averages over the best-fit period: Vsw = 533 km/s B = 7.4 nT = AU
Density profiles by NM Apr. 11 CMEAug. 27 CME