Interpreting real-time space weather data conditions for solar phenomena

[astra]

hello! I'm interested in looking at raw data and coming up with conclusions for different solar phenomena but I'm a total beginner.

I'm specifically interested in the aurora & CME - is it possible to deduct these only with the numbers in real-time?

So for example, if the solar wind speed is > 600km/s AND bz is < -6 AND the solar wind density is > 15 p/cm3, then the aurora will be visible? Or is it simpler than this?

With the CME, is this totally dependent on the solar flare activity or is there something else I could be looking at?

Thank you :)

[Vancanneyt Sander]

It’s actually a lot more difficult than you are currently sketching…

First, because you’re new, you’ll have to learn the basics first so you can understand all solar and geomagnetic phenomenon before getting into the data. Once you’ve learned the basics, it’s easier to interpret the data. A good start is to read all articles in our help section on the app and site.

Second, to know what conditions might be good to have aurorae, it’s also important for what location you want to know it. With a solar wind speed of 400km/sec and Bz slightly southward there is likely already Aurora at high latitude locations. If you’re in a lower middle latitude location it would need a lot more.

Third, solar wind data and IMF data are good to know before heading out. They give you up to an hour in advance the conditions, so if Bz is southward for a prolonged period the odds of storm initiation is higher. But to really know the odds for your location, look for a magnetometer station nearby as those are the best way to see if you can run outside to see the Aurora or not. 

[astra]

Thanks so much for your reply

It's more that I'm interested in the specific data that has to combine in order to form these phenomena, not so much the local conditions so I can see the aurora myself.

I've read the help section and there's a lot I'm already familiar with, it's just the specific data I can't find that much info about.

[Vancanneyt Sander]

As with each storm you'll follow, you'll see that there is no way you can define exact tresholds for the aurora to appear. So you can't say "with that solar wind speed this will happen" or "with that Bz that will happen". The lower the latitude, the more parameters that need to be right. 

With the CME's of a few days ago, we're still waiting for the arrival of them, they are now past the calculated impact window which means that the impact will be less significant (less speed) or that the first two completely missed us. When it arrives, we'll have to look at the parameters of IMF and solar wind, the solar wind is not that important for high latitude aurora but for middle latitudes a higher speed would be better. The IMF needs to be southward oriented but as with many CME's it wobbles to north and south before going into a dominant direction. This will have a great impact on the storm initiation. A Bz of -15nT for a few hours will generate a bigger storm than when it wobbles between North and South. If it's long enough southward, let's switch over to magnetometers, for my location i'll use the Kiruna magnetometer where we'll need a big deflection to be able to even see it where i'm from. 

if you have questions about the data or special cases you want to discuss, let yourself go 😉 we'll do our best to help ya out.

[helios]

Although, there are models which describe pretty well the expected location and intensity of aurorae.

The OVATION model is used to generate the aurora oval map which is shown on the front page of spaceweatherlive.

The model is described in further details here:
http://sd-www.jhuapl.edu/Aurora/ovation/

And a bit further (OVATION prime) here: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2011SW000746

 

Edited May 26, 2021 by helios

[Tristan]

The speed, density, and magnetic field strength have all jumped higher indicating that the first CME has just arrived at DISCOVR.

[Vancanneyt Sander]

2 uren geleden, Tristan zei:

The speed, density, and magnetic field strength have all jumped higher indicating that the first CME has just arrived at DISCOVR.

Second CME was more rapid than the first when they took off on the Sun so likely the impact we’ve seen this afternoon is of the two CME’s with one still on the way. 
and as expected, it wasn’t a big hit With the IMF not even to moderate strength and a northward direction so untill now stormless impact.

[Tristan]

36 minutes ago, Vancanneyt Sander said:

Second CME was more rapid than the first when they took off on the Sun so likely the impact we’ve seen this afternoon is of the two CME’s with one still on the way. 
and as expected, it wasn’t a big hit With the IMF not even to moderate strength and a northward direction so untill now stormless impact.

Lets hope there is another. The solar wind speed was below 300km/s before it hit so they could all have merged with each other, or do you think there is enough of a gap for another impact?

[Vancanneyt Sander]

10 minuten geleden, Tristan zei:

Lets hope there is another. The solar wind speed was below 300km/s before it hit so they could all have merged with each other, or do you think there is enough of a gap for another impact?

Well it was already way overdue so the two should have catched up anyway and slowed further down with a late impact as a result. The third one was predicted to arrive this afternoon with a + and - of 7 hours so that impact window is still open

[abc]

In fact, how does solar wind density matter?

[stevenfraussen]

2 minuten geleden, abc zei:

In fact, how does solar wind density matter?

Basically it means there are more particles coming at us. This in turn means there are more particles interacting with nitrogen and oxygen in our ionosphere which means better/more aurora. Problem right now is that the IMF is positive which means the ionosphere is "closed" for the solar wind particles. 

So in short: particles are coming at us but can't interact with our ionosphere because of the positive IMF. Let's hope it turns south, which can always happen during a CME impact.

[abc]

28 minutes ago, stevenfraussen said:

Basically it means there are more particles coming at us. This in turn means there are more particles interacting with nitrogen and oxygen in our ionosphere which means better/more aurora. Problem right now is that the IMF is positive which means the ionosphere is "closed" for the solar wind particles. 

So in short: particles are coming at us but can't interact with our ionosphere because of the positive IMF. Let's hope it turns south, which can always happen during a CME impact.

Luckily. The IMF has reached moderately strong and it turned soutg

[David K]

Density isn't as important as speed either, it helps but you can have impressive aurora with fairly low density.