ionospheric responses to the particular solar events

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 Mar. 09 – HSS Magnetic field

Velocity of SW

9 11 137 day

9 11 137 day

B

By

Bx

Bz

vy

vx

vz

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

Geomagnetic response in Dst

The strongest response for MC L

Similar values of Dst drop

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…

Diurnal course of foF2 and h’F2 after HSS

foF2

h’F2

2

4

6

8

10

MHz

4 106 8 12 14day

200

400

km

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)

Diurnal course of foF2 and h’F2 after MC R

foF2

h’F2

10 168 12 14 day

6

4

MHz

2

8

200

400

km

10

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

Diurnal course of foF2 and h’F2 after MC L

foF2

h’F2

6 104 8 day12 14

6

4

MHz

2

8

10

200

400

km

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