Again stealthy cme

[Isatsuki San]

LThe density is at 30 and I wanted to know if it is due to Again  stealth cme or if it was predicted 

Edited April 10, 2023 by Isatsuki San

[Philalethes]

Off the top of my head it could possibly be the recently passing coronal hole.

[Jesterface23]

Yeah, with the solar wind velocities so low the CIR arrival can act as a sort of shock.

[Sam Warfel]

8 hours ago, Jesterface23 said:

Yeah, with the solar wind velocities so low the CIR arrival can act as a sort of shock.

Spaceweather.com called it a CME, but they have been wrong and it is often hard to tell for sure on something like this.
There's no incoming CH that could give a CIR though, is there? So maybe CME is most likely.

[Jesterface23]

1 hour ago, Sam Warfel said:

There's no incoming CH that could give a CIR though, is there? So maybe CME is most likely.

There was a CH right above the line splitting the northern disk about 3-4 days ago. I hadn't checked at the time of my post, but the density was dropping and velocities and temp rising giving the classic CH HSS arrival.

I think CIRs, or maybe non-CME SIR, can rarely reach or go above 400km/s on arrival when the velocities prior are so low.

.......

And the CH,

Edited April 10, 2023 by Jesterface23

[David Silver]

I believe the disturbance and CIR can also be at the outgoing edge of a solar wind stream, one of which just passed.

[Andrey M]

But what can you say about EPAM in this case? Is it not an indicator of CME? 🤔

[Jesterface23]

46 minutes ago, Andrey M said:

But what can you say about EPAM in this case? Is it not an indicator of CME? 🤔

The EPAM began to rise as the CIR entered, so any possible CME would have been behind it. The EPAM peaked around the time the CH HSS fully arrived, as the high proton density was no longer blocking the EPAM.

The EPAM can help tell when a CME may be in the area, but doesn't guarantee a CME arrival.

[Andrey M]

1 hour ago, Jesterface23 said:

The EPAM began to rise as the CIR entered, so any possible CME would have been behind it. The EPAM peaked around the time the CH HSS fully arrived, as the high proton density was no longer blocking the EPAM.

The EPAM can help tell when a CME may be in the area, but doesn't guarantee a CME arrival.

Ok, we will assume that in this case a random cocktail has arisen and it is difficult to extract individual pure parts from it 🍹

[Philalethes]

7 hours ago, Andrey M said:

we will assume that in this case a random cocktail has arisen and it is difficult to extract individual pure parts from it

I don't think that was the point or the conclusion. The point was rather that there wasn't really any indication of anything else than the HSS arriving, since the EPAM rise doesn't indicate a CME by itself; at least that's how I understood it, and what seems to be the case.