How long does solar winds last on effecting Earth?

[oemSpace]

When solar winds hit on Earth's ionosphere, does anyone have any suggestions on how long this weather disturbance last on Earth?

Thanks in advance for any suggestions

[Vancanneyt Sander]

The solar wind is always here blowing in normal conditions around 300km/sec. The speed can rise to higher values when solar storms arrive coming from a coronal hole, CME or filament eruption. The duration of a disturbances depends on the type of solar event, the size of the event and some more things. 

For example a large recurrent coronal hole at the center of the solar disk can have an elevated speed for more than 3 days but here it will depend on the size of the coronal hole and the exact location to know how long it can last.

With CME's it's a diffferent thing because much depends on the movement and direction of the event, the highest speeds are at the front itself and can last for more than a day depending on the size of the event, a small CME can also be unnoticed in the speed readings.

[oemSpace]

When solar winds hit on Earth,

• Does the plasma from solar winds directly generate a geomagnetic storm on Earth?
• How long do this disturbances of geomagnetic storm last? Would it be disappeared after solar winds pass through Earth's surface?

Do you have any suggestions?

 

Thanks you very much for any suggestions

[Vancanneyt Sander]

no suggestions, we give real awnsers ;-)

 

Does the plasma from solar winds directly generate a geomagnetic storm on Earth?

No, it doesn't generate a storm immediatly. It will depend on the direction of the IMF and the strength of the IMF, this together with the solar wind density and speed. For example a slow mooving CME of 350km/sec with a low density of 5 particles per kubic cm and an IMF strength of 6nT and direction of -2nT will not generate a thing. If an impact was detected of 700km/sec with a density at impact of 40 and a moderately strong IMF of 15nT and southward Bz of -6nT may generate a storm only if the values persist (with the IMF as main parameters)

How long do this disturbances of geomagnetic storm last? Would it be disappeared after solar winds pass through Earth's surface?

Like i've said earlier, that depends on the type of disturbance that arrived (CH, CME). See earlier examples. Every disturbance wether it's from a CME or CH the speed returns to normal conditions in a normal pase at all different timeframes. The exact duration can't be predicted and it all depends on the type of disturbance and the paramaters opf it when it lifted off in case of a CME and in case of a coronal hole  how big the hole was.

[oemSpace]

Thanks you very much for suggestions