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Ionospheric responses to the particular solar events
Zbyšek Mošna1,2, Petra Šauli1 , K. Georgieva3
1- Institute of Atmospheric Physics ASCR, Prague, Czech Republic
2- Department of Surface and Plasma Science, Charles University, Prague, Czech Republic
3- Solar-Terrestrial Influences Laboratory, BAS, Bulgaria
Solar events
Three events from year 2004 High Speed Solar Stream (HSS,
Mar 09) Magnetic Cloud with rightward
rotation of magnetic field (MC R, Feb 11)
Magnetic Cloud with leftward rotation (MC L, Nov 07)
2004 Feb. 11 - Magnetic Cloud R
12 13 1411day
B
By
Bx
Bz
vy
vx
vz
12 13 1411 day
Magnetic field
Velocity of SW
2004 Nov.07 - Magnetic Cloud L
By
Bx
Bz
vy
vx
vz
8 9 107 day8 9 107 day
Magnetic fieldVelocity of SW
Ionospheric vertical sounding (1)
Quiet ionogram - Pruhonice observatory Mar. 11, 2004
200
400
800
600
(km)
1000
h’F2
2 4 6 8(MHz)foF2
Plasma frequency profile
F2
Analyzed data: h’F2, foF2, plasma frequency profile
9 days for each event (4 days before are reference,15 min resolution)
Ionospheric vertical sounding (2)Disturbed ionogram – Pruhonice observatory Feb. 12 2004
4 6 8 (MHz)
200
400
800
600
(km)
2
1000
Problems: splitting, spread, vanishing, blanketing…
Scalogram – time evolution of the plasma frequencies profiles after HSS
4 6 8
200
400
km8
6
4
MHz
Passing of Traveling Ionospheric Disturbance (TID)
Scalogram – time evolution of the plasma frequencies profiles after MC R
8
6
4
MHz
2
10 168 12 14 day
Oscillations – wave-like structures remain several days – AGW with source in the midlatitudes
Scalogram – time evolution of the plasma frequencies profiles after MC L
8
6
4
MHz
26 104 8 day12 14
200
Conclusion
Similar and high response to the solar events for several days in case of HSS and MC L (although very different Dst)
HSS, MC L: Decrease of foF2 and plasma frequencies in the height profile and increase in h’F2
Oscillations of h’F2 after passing the TID Wave-like structures with the source in midlatitudes MC R: No significant change in mean values of daily
ionospheric parametres, decrease in night foF2, oscillations of the h’F2 and in plasma frequencies profile