IMF (South) + Solar winds = CME?

[oemSpace]

[Guest CalleB]

Correct me if I'm wrong, by all means.

First, I belive that what we are seeing in the model isn't a CME (coranal lass ejection) but a stream of solarwind, escaping from a hole in the Sun's corona. That's usally not affecting Earth as much as a CME, therefore the expected conditions is "ambient".

With a south diverted IMF, the gust of the solarwind shown in the model ( I think ) can spark Auroras a bit further south, than if the IMF was north diverted.

Other people can surely give you a better answer.

[Vancanneyt Sander]

Like CalleB said (welcome onto the forum ;-) ) this is a coronal hole, for information about that look in the help section of the website.

The IMF polarity at earth, second graph, is not the direction of the IMF!

So when it's in a negative sector (-) that means that the magnetic field lines of the Sun that stretch out far into our solar system are going towards the Sun. When we are in a positive sector, that means that the magnetic field lines of the sun are going away from the Sun. The figure above shows that nicely. So in the graph there is a representation of the model that predict the polarity of the IMF if it is positive (+ Away) or negative (- towards).

Bz is the direction of the IMF and NOT the polarity. See help article about the IMF.

The Bz is something that you can not predict that easy and is something scientist are still struggling on. Last CME impact was predicted to have a southward direction of the IMF but it was north.

[oemSpace]

The IMF polarity at earth, second graph, is not the direction of the IMF!

So when it's in a negative sector (-) that means that the magnetic field lines of the Sun that stretch out far into our solar system are going towards the Sun. When we are in a positive sector, that means that the magnetic field lines of the sun are going away from the Sun. The figure above shows that nicely. So in the graph there is a representation of the model that predict the polarity of the IMF if it is positive (+ Away) or negative (- towards).

Bz is the direction of the IMF and NOT the polarity. See help article about the IMF.

The Bz is something that you can not predict that easy and is something scientist are still struggling on. Last CME impact was predicted to have a southward direction of the IMF but it was north.

 

I am little confused between Bz and IMF Polarity

 

1) Bz (Southward) + positive polarity of IMF = CME?

2) Bz (Southward) + negative polarity of IMF = CME?

3) Bz (Northward) + positive polarity of IMF = CME?

4) Bz (Northward) + negative polarity of IMF = CME?

 

Does anyone have any suggestions on what combination would generate CME? 

 

Thanks, to everyone very much for any suggestions :>

[Vancanneyt Sander]

How can you be confused? I just explained in my last post!

Your equations are all wrong... The polarity of the IMF does NOT make the direction of the IMF go south or north.

The IMF polarity and Bz does NOT generate a CME. CME's are generated when a solar flare occurs, during that process the magnetic field lines of the sunspot group break open and releases a cloud of charged particles into space and that is a CME. Along magnetic field lines of a sunspot region hot material of the sun flows along it, you can see that very nicely with prominences on the Sun. If that breaks, the plasma can get released into space generating the CME.

I recommend that you reread all what we already told you because you're mixing a lot of things up and things we already explained to you multiple times.

[oemSpace]

Earth is located sometimes above and sometimes below the rotating heliospheric current sheet, it experiences regular, periodic changes in the polarity of the IMF. These periods of alternating positive (away from the Sun) and negative (toward the Sun) polarity are known as magnetic sectors.

 

Bz is a measure of the component of the IMF out of the ecliptic plane.  When Bz is oriented southward the IMF can reconnect with the Earth's magnetic field…
 

so I would like to determine whether a stream of solarwind or CME (coranal lass ejection) can impact on Earth's magnetic field or not, just like monitoring the weather to determine whether it is a rainy day or not, are those graphs correct to monitor solarwind or CME for this impact?

 

Does anyone have any suggestions?

 

Thanks, to everyone very much for any suggestions :>

[Vancanneyt Sander]

Earth is continuesly under influence of the Sun and Always has an impact on our magnetosphere. There is Always solar wind, there are Always particles from the Sun that slam into the magnetosphere... The ONLY thing is that there can be coronal holes and coronal mass ejections that can bring more significant effects to the Earths magnetosphere.

It is a bit like the weather, but more complicated to predict. And all of the charts on the site helps us with making the predictions.

[oemSpace]

When Bz is oriented southward the IMF can reconnect with the Earth's magnetic field…

As long as Bz is oriented southward the IMF , I would like to know what happen on following situations:

1) Bz (Southward) + positive polarity of IMF

2) Bz (Southward) + negative polarity of IMF

 

How is a stream of solarwind impact differently on Earth's magnetic field?

 

Does anyone have any suggestions?

 

Thanks, to everyone very much for any suggestions :>

 

 

[Vancanneyt Sander]

No and No.

We said it earlier and i repeat it again and again... If the direction of the IMF is southward orientated this wil propagate charged particles into the Van Allen belt on Earth. These charged particles enter our atmosphere and collide with particles of our atmosphere and generate energy. To release that energy it will emit light, that light we can see as Aurora.

If the direction of the IMF is northward, it gets deflected and will flow over the Earth and cause no geomagnetic storming (only in extreme cases like with a very very high solar wind speed and strong strength of the IMF it would be another story).

So once again, the polarity of the IMF has nothing to do with the direction of the IMF. Why? Because the IMF is a vector quantity with a three axis component as we've said in our help article and that has nothing to do with the polarity it has.

[oemSpace]

Referring to following image 1, if the direction of the IMF (Bz) is southward orientated, this will propagate charged particles into the Van Allen belt on Earth, which would impact on the colored sectors on sunny sides, including

• North Pole
• Tropic of Cancer
• Equator
• Tropic of Capricorn
• South Pole

Would it be correct? so do we mainly monitoring Bz - the direction of IMF for Aurora and not need to monitor IMF Polarity?

 

Referring to image 2, of course, if we look for Aurora, we mainly monitor Bz and Solar wind speed for any potential Aurora, would it be correct?

 

Referring to image 3, if we want to monitor the detailed particles within the solar winds on the ACE satellite, we look at EPAM, and assume the similar components would hit the Earth's surface, would it be correct? Please correct me if I am wrong ...

 

 

Thanks, to everyone very much for any suggestions :>

 

 

Image 1

 

 

 

Image2

 

Image 3

[Guest Plan9]

Is that you Jose?

[Vancanneyt Sander]

OEM... How many times do we have to repeat ourselves...

IMF Polarity is used to determine in which sector we are (positive or away) and helps scientists in predicting the space weather in a way that's too complicated for you to understand. CME modeling comes in place too and with lots of equations a prediction is made of what a CME or CH can do.

For a geomagnetic storm we monitor all solar wind data, all IMF data, all magnetometer data. The Bz is a key in the whole thing because that will determine if a geomagnetic storm will happen or not because a southward Bz is needed to get things running.

And i refer to the following image where it's illustrated at it's best. Solar wind flows past us and the magnetic field of the Earth (magnetosphere) deflects it away from the poles. If the direction of the IMF is southward, than the charged particles that are carried with the solar wind get injected to the Earth where the magnetic field lines of the Earth go in to the atmosphere and that's where the Van Allen belt is. The particles end up in our atmosphere and will collide with particles of our atmosphere and thus to release it's energy to return to it's normal state it emits light.

Do you understand?

Did you read what we said?

[oemSpace]

 If the direction of the IMF is southward, than the charged particles that are carried with the solar wind get injected to the Earth where the magnetic field lines of the Earth go in to the atmosphere and that's where the Van Allen belt is. The particles end up in our atmosphere and will collide with particles of our atmosphere and thus to release it's energy to return to it's normal state it emits light.

 

Referring to following images, when I watch the video, it seems those charged particles only going to both poles without any description on following area, so I would like to confirm whether those particles would also collide with particles of following regions instead of both poles alone or not. That is the new discussed point.

• North Pole
• Tropic of Cancer
• Equator
• Tropic of Capricorn
• South Pole 
   

 

There is one thing I don't understand between monitoring magnetograms and EPAM,

 

EPAM is an instrument on the ACE satellite, which can determine the impact, so we know if a CME is Earth directed and when it's going to arrive.

 

Magnetogram is measured by the ground station, which can see if there are aurora chances in your local area.

 

Would it be the main different and purpose for their measurements?

 

so if I want to monitor solar winds instead of aurora chances, should I select EPAM instead of any Magnetogram for monitoring? and I keep my eyes on Bz all the times. Would it be correct?

 

Does anyone have any suggestions?

 

Thanks, to everyone very much for any suggestions :>

[Marcel de Bont]

Aurora shows up in ring shaped ovals around the magnetic north and south pole. This is where the solar particles get ejected into our atmosphere. The higher the geomagnetic activity, the larger these rings get. It is extremely rare to see aurora on latitudes like the Tropic of Cancer, only the most extremest of geomagnetic storms might be able to get aurora there but those are not the kind of storms we would like to see.

First you look at the SWEPAM (NOT just EPAM!) and MAG data from ACE. These show the solar wind properties and the status of the IMF at the L1 point in space. Magnetometers show the current geomagnetic conditions on Earth. Combine the two if you want to know what the geomagnetic activity is going to do.

[oemSpace]

First you look at the SWEPAM (NOT just EPAM!) and MAG data from ACE. These show the solar wind properties and the status of the IMF at the L1 point in space. Magnetometers show the current geomagnetic conditions on Earth. Combine the two if you want to know what the geomagnetic activity is going to do.

 

On following image, it shows clearly the warning zone related to Bz and Speed, so there is no problem on interpretating those items within SWEPAM,

 

 

but there is not much description on how to interpret SWEPAM and MAG data for CME on your reference, such as Phi, Density, and Temp.

Could you please tell me more on how to interpret those items related to the solar wind properties?

 

SWEPAM and MAG

 

 

Furthermore,  is there any Magnetometers showing the current geomagnetic conditions on Asia?

 

Does anyone have any suggestions?

 

Thanks, to everyone very much for any suggestions :>

[Vancanneyt Sander]

There is no warning zone on that image! it is just a combination of speed and bz in one graph and of that one image you can't interpret the chances for aurorae on that moment in time. What you need are the raw data like wind speed, density, direction of the imf, strength of the imf and magnetometer.

The other parameters phi and temp are less important. The temp = temperature and you'll see with a CH that this rises slowly when the onset phase of the CH starts, once the sector boundary is reached phi rotates with more than 180 degrees indicationg that we crossed the sector and are in the IMF sector with an other polarity. With CME's the temperature rises abruptly and normall phi would swingle arround for a bit and is normal. But that is not needed for aurorae prediction (except by scientist who doe pretty insane equations).

Most of the countries have a magnetometer station. You can even order your own magnetometer with a SAM station. Every magnetometer stat. Every official magnetometer station has it's own deflection values in nanoTesla to derive a K-indice for it. Like with the official Kp, it takes every observed K-indice of those magnetometer stations and gives us the official Kp which is the planetary K-index and gives you an idea of the strength of a geomagnetic storm for the past three hours.

[oemSpace]

There is no warning zone on that image! it is just a combination of speed and bz in one graph and of that one image you can't interpret the chances for aurorae on that moment in time. What you need are the raw data like wind speed, density, direction of the imf, strength of the imf and magnetometer.

 

 

Do you see the the image combining speed and bz in one graph is easy to understand? it shows green (safe), yellow (OK), and red zone (warning). 

 

When you talk about those raw data, could you please give me any suggestions on how you interpret the chances for aurora?

 

Does anyone have any suggestions?

 

 

Thanks, to everyone very much for any suggestions :>

[Marcel de Bont]

Do you see the the image combining speed and bz in one graph is easy to understand? it shows green (safe), yellow (OK), and red zone (warning).

Easy to understand, perhaps, but it doesn't provide a whole lot of info. The red part of that graph just shows that geomagnetic activity is likely to increase.

 

When you talk about those raw data, could you please give me any suggestions on how you interpret the chances for aurora?

We are not doing that anymore, we have been explaining this multiple times now.

 

 Here you can find an Asian magnetometer: http://www.sam-magnetometer.net/

Asia

Low latitude

Kislovodsk

Russia

[oemSpace]

First you look at the SWEPAM (NOT just EPAM!) and MAG data from ACE. These show the solar wind properties and the status of the IMF at the L1 point in space. Magnetometers show the current geomagnetic conditions on Earth. Combine the two if you want to know what the geomagnetic activity is going to do.

 

After discussion, I would look at following charts :

 

To show the solar wind properties and the status of the IMF at the L1 point in space.

 

 

To show the impact of solar winds' status.

 

 

For the Asian magnetometer, it is too far away from China and Japan, which is not representive for Asian region.

 

 

 I hope the chart selections are correct :>
Thanks, to everyone very much for suggestions :>

[Vancanneyt Sander]

Like we said dozen of times....

EPAM is a graph that let's yo used if there was a possible earthward component of a CME. Strong eruptions are visible in the low energy electrons (top part), in the low energy protons you can see a sharp onset phase of a CME that is heading our way, when it peaks, we would expect an impact of stronger solar wind at ACE. SO conclusion: EPAM is used to see if there was an earthward component of a CME and it gives you a glimpse of when it's about to arrive. It does not indicate the strength of a geomagnetic disturbance.

In the first image of your last post you have the main data of the solar wind and IMF. But that's in a graph and you can read on it what the strength of the solar wind was etcetera. What i meant with raw data isn't a graph but textual data like for example a speed of an average of 800km/sec in a 2h period where the IMF would be for example southward orientated with a maximum extent during that 2h period of -10nT and a strength of 15nT during that period. According to those data we could assume that a G1 storm can be produced if conditions remains the same (in practice all data verses much so it's the recent data that has to be exam end continue sly to know if there are still chances or not.

The last image is a magnetogram like there are many that you can find online. The best magnetogram is the one that is closest to you. We've explained the magnetogram also a dozen of times so i won't repeat myself again and again.

The magnetometer is the mast chain in the puzzle for aurorae chasers. Like for the kiruna magnetogram a deflection of more than 1200 nT would be sufficient enough to see aurorae on a mid latitude location but only for the duration of that deflection. (details are in the help article so read it instead of questioning everything we already told).

[Guest Australis]

@ oe7110

 

If the IMF is directed towards the sun + CME passes the earth northwards  :  the IMF turns southwards. (a negative Theta angle)

 

If the IMF is directed toward the sun + CME passes the earth southwards   : the IMF turns northwards. (a positive Theta angle)

 

If the IMF is directed away from the sun + CME passes the earth northwards   : the IMF turns northwards. (a positive Theta angle)

 

The location of the  heliospheric current sheet is important to forecast the theta angle.

 

Satellites measure the strength of the interplanetary magnetic field and from this information, the direction of the IMF can be deduced.

The ACE spacecraft routinely measures this information. The direction of the IMF in the plane of the ecliptic (toward the S un or away
from the Sun) is determined by the Phi angle. An angle near 360 (or zero) degree s, plus or minus about 90 degrees, indicates that the IMF

is directed toward the Sun in the plane of the ecliptic. The angle of the IMF inclined to the ecliptic (north or south of the e cliptic plane) is
determined by the Theta angle, and it is this angle which is most critical in te rms of
forecasting the strength of geomagnetic disturbances.

 

So, your way of thinking is correct !