Sunspot region 2830, cycle 24 or 25?

[3gMike]

Would this Alpha spot (2803 at N21) be classified as Cycle 24?

 

[Vancanneyt Sander]

First: don’t post off topic in a topic. It’s a separate question for a separate topic so we’ve moved your post in this new topic

Due to the latitude of AR12803, it can’t be a cycle 24 region. If it was a cycle 24 region, it would appear around the equator which isn’t the case here. Second, when it appeared, the regions spot configuration where a correct SC25 signature: left spot red (trailing), right spot blue (leading) (beta magnetic configuration). The picture you posted was of his last day it was numbered and when you look at the visual HMI it was already spotless. Okay on it’s last two days it appears blue/red but mostly because it lost it’s trailing spots (red) becoming an alpha region with a single polarity. And the northern hemisphere dominant polarity is… blue.

[3gMike]

Thanks,

I should have quoted the comment earlier in the topic, which was discussing terminator location. I felt that this spot could not be Cycle 24 due to the latitude, but was confused by the image & clearly had not checked the full history of that region. On that basis I would say that the last Cycle 24 spot was Region 2766 in July 2020, so that will presumably be identified as the terminator.

[abc]

I'm not sure whetehr I am right or not but according to an article last month 

Quote

We call it the Termination Event,” says Scott McIntosh, a solar physicist at the National Center for Atmospheric Research (NCAR), “and it’s very, very close to happening.”

 

from https://fakta360.no/2021/06/something-big-may-be-about-to-happen-on-the-sun-the-termination-event/

I believe this is because swpc only name active regions which last for at least a day. As a result, some very tiny spots that cannot be easily detected wuth our naked eyes and some very short-duratio bspots are not numbered. Techbically, region 2766 is the last cycle 24 spot. Yet, the terminator has not been reached when we consider the magnetic changes and the occasional emergence of tiny reversed polarity regions which are short-lived.  But this will happen soon

[Christopher S.]

48 minutes ago, abc said:

I'm not sure whetehr I am right or not but according to an article last month 

from https://fakta360.no/2021/06/something-big-may-be-about-to-happen-on-the-sun-the-termination-event/

I believe this is because swpc only name active regions which last for at least a day. As a result, some very tiny spots that cannot be easily detected wuth our naked eyes and some very short-duratio bspots are not numbered. Techbically, region 2766 is the last cycle 24 spot. Yet, the terminator has not been reached when we consider the magnetic changes and the occasional emergence of tiny reversed polarity regions which are short-lived.  But this will happen soon

While you're correct in pointing out the technicalities, remember that criteria for numbering spots is designed in such a way to filter out these "stragglers" so that termination events are more clear and the sunspot number stays consistent and accurate to historical solar cycle progression. It is by our conventions that we can say with certainty that SC24 is done, and that becomes difficult to say if we were to keep loose definitions of such things

[abc]

I have to agree that solar cycle SC24 is done. However, the termination event is define as 

Quote

oppositely-charged bands magnetism collide at the Sun's equator,

which is not simply when significant solar cycle 24 spots disappear

Edited July 10, 2021 by abc

[Christopher S.]

1 hour ago, abc said:

I have to agree that solar cycle SC24 is done. However, the termination event is define as 

which is not simply when significant solar cycle 24 spots disappear

From what I read of the article you posted, what they call the "terminator" is not academically the same as what we've been talking about here on this forum. The terminator as I understand it is not as eventful as the article implies. Also, you're reading a bit too much into somewhat vague descriptors in a news article in which controversial predictions are also made about SC25. Take it with a grain of salt.

The terminator itself, from my observations, cannot even be described as an event. It's similar to solar minimum; When charting out data points, it then manifests itself to us, but we don't know it until much later. Some describe it as just before the final signs of the previous solar cycle disappear, others describe it as when there is absolutely no evidence of the previous cycle. The novel research of NCAR tries to associate the behavior of these terminators with the succeeding solar cycle's strength, which in and of itself puts significance on said event, but there is likely subjectivity and bias still within that very research. 

In my opinion, we should not be too strict with definitions based on loose interpretations or unconfirmed research/predictions. This would disallow us from seeing other things which could contribute to or annihilate the premise of that particular research article.

Edited July 10, 2021 by Christopher S.

[3gMike]

On 7/10/2021 at 3:46 PM, abc said:

I have to agree that solar cycle SC24 is done. However, the termination event is define as 

which is not simply when significant solar cycle 24 spots disappear

I found this article concerning the NCAR research which indicates that they originally predicted the end of Cycle 24 would "occur in the first half of 2020, Kicking off growth of Cycle 25 very shortly after" so perhaps they do have a useful method for predicting the location.

 

https://www.sciencedaily.com/releases/2019/07/190724090241.htm

[Newbie]

On 7/3/2021 at 10:02 PM, Vancanneyt Sander said:

First: don’t post off topic in a topic. It’s a separate question for a separate topic so we’ve moved your post in this new topic

Due to the latitude of AR12803, it can’t be a cycle 24 region. If it was a cycle 24 region, it would appear around the equator which isn’t the case here. Second, when it appeared, the regions spot configuration where a correct SC25 signature: left spot red (trailing), right spot blue (leading) (beta magnetic configuration). The picture you posted was of his last day it was numbered and when you look at the visual HMI it was already spotless. Okay on it’s last two days it appears blue/red but mostly because it lost it’s trailing spots (red) becoming an alpha region with a single polarity. And the northern hemisphere dominant polarity is… blue.

Ok this is where I have been confused. When a spot takes on the appearance of reversed polarity it's because it has lost trailing spots but it won't be an old cycle spot if it doesn't occur around the sun's equator.

So then a spot is initially determined by its east-west configuration and in the case of a simple alpha region, its north-south configuration.

Thanks for the 'enlightenment' 😁

Edited July 20, 2021 by Newbie