Jump to content
Sign in to follow this  
DTR

Current Sunspots and how they are accounted for

Recommended Posts

Hello, I've been lurking here for several months.  Currently sunspot #2755 has been on the earth facing side of the sun.   How is that sunspot accounted for, when I view silso they show 

03 January : 14
04 January : 13
05 January : 14
06 January : 12

07 January : 17

What exactly do those numbers represent, is it the sunspot intensity?  If someone can give us newbies a basic understanding it would be great.  Thank you

  • Like 1

Share this post


Link to post
Share on other sites

Hi, welcome to the forum.  

"The formula is: R(relative number) = (10 * number of groups) + (number of spots)." taken from this link, where there is an example tallying of spots. 

Thanks for starting the topic, because I thought the jump in spots over the last day, and you bringing it up, is a topic that should be highlighted and understood.  Some parties do question whether our modern technology is resulting in an inflation of spot count, whereby small pores are being counted in current times that would not have been counted decades ago.  

I understand a few scientists have put a lot of work into trying to reconcile these types of considerations in the historical sunspot record. Nonetheless, it is the specific type of inflation count that we see today (07 January) that still leads me to question the process.

I hope that helps?

  • Like 4

Share this post


Link to post
Share on other sites

Yea, I question some of the spots as well.  For instance on Nov 14th, nearly everywhere I had looked on the internet had a spotless sun, yet Silso recorded some spots for that day.  However, most people said there were some very weak spots that had disappeared during that day, and they shouldn't have been counted.  My reasoning is that there would have been 54 spotless days, and would have been tied with 3rd alltime (since 1849).  They need to keep the old method alive to reconcile with our past, and I don't have a problem if they have a new method with new technologies that is separated from the historical record.

Share this post


Link to post
Share on other sites

As stated on the silso page: 

Please note that the number and stretches of spotless days may differ from those of other sources (e.g. NOAA,…). The reason for this is simply because we (SILSO) are using a different network than e.g. NOAA.

the observation time differs from those of noaa. On November 13th there was a plage region that probably had one spot during the observations of silso observatories and when NOAA woke up and looked there where none left. 

  • Like 2

Share this post


Link to post
Share on other sites

What specifically threw up a red-flag for me was when the SILSO plot was initially displaying a value of 17 on Jan 7th.  However, it wasn't too long after my reply to DTR that the plot was corrected to the value of 0 for the 7th.  

4 hours ago, DTR said:

They need to keep the old method alive to reconcile with our past, and I don't have a problem if they have a new method with new technologies that is separated from the historical record.

It is not that simple, and the heliophysicists involved with the relatively recent 'correction' to the sunspot record, bringing it to Version 2, have put a lot of research, thought and time in getting to where we currently are.  (Here is a link to get one started for those interested in reading the scientific literature:  https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=svalgaard+sunspot+record&oq=svalgaard+sunspot .)

  • Like 1

Share this post


Link to post
Share on other sites
Posted (edited)

Converse to 'spot count inflation', another thing to keep in mind is the usual delay between the time sunspots first appear on the disk, and the time the SILSO network registers them on their plot.  For example, a new SC25 Active Region (figure below) has been producing sunspots for the past 9-10 hours, but we do not yet see any registration to that effect on the SILSO plot.

1-8-2020.thumb.jpg.af18e4628e2c5c626cb7ad37e99d79a6.jpg 919170882_EISNcurrent1-8-20.png.79cfbd159cae16f03dc208db829d9cc0.png

 

Maybe a sunspot observer 150 years ago would likely have seen similar types of spots, even using an antiquated telescope, and thus recorded them without delay. But if those spots live for only 12 hours total, whether such a observer would have even seen the spots would depend upon which side of the planet they lived on.

Edited by theartist

Share this post


Link to post
Share on other sites
Posted (edited)
On 1/8/2020 at 3:55 PM, theartist said:

Maybe a sunspot observer 150 years ago would likely have seen similar types of spots, even using an antiquated telescope, and thus recorded them without delay. But if those spots live for only 12 hours total, whether such a observer would have even seen the spots would depend upon which side of the planet they lived on.

 

How would that have been dealt with in the record if Scientists in Europe had no recorded spots, however in the US there we several recorded spots?   Or have they never collaborated with the data?

Edited by DTR

Share this post


Link to post
Share on other sites

I don't understand your question.  Are you suggesting that in the past a lot more spots were recorded in the US than in Europe? If so, please cite your source.

Share this post


Link to post
Share on other sites

No in the previous post you mentioned that in the past different sites in different parts of the world could be different depending on the times they looked through the telescopes for spots.  In this scenario, how was that handled?  In my last post that was an example for this same question.  I'm just trying to figure out the process on how they've recorded sunspots from different stations around the world and if they shared their results with each other, and if their results differed how did they handle the count?

Share this post


Link to post
Share on other sites
12 hours ago, DTR said:

in the previous post you mentioned that in the past different sites in different parts of the world could be different depending on the times they looked through the telescopes for spots.  In this scenario, how was that handled? 

I was discussing the hypothetical situation of short-lived spots lasting <14 hours and presenting themselves on the side of the planet where an observer is fortuitously located. In such a situation, did they really exist long enough to be counted as spots, and would they have been, nonetheless, counted long ago?  For this reason, in olden-times, before worldwide observation and communication, there was likely more differences in sunspot records between the (relatively paltry compared to today) number of observers located on different sides of the planet.  

But that issue doesn't even touch upon the element of human subjectivity in the process.  Here is what the SILSO plot looked like, at one time, in the past 24 hours:

1107921092_1-9-20EISNcurrent.png.259e5a81d83feb08ca2f88c29df43547.png

At one time, there were spots tentatively being recorded for the 9th.  The grey area indicates the fluctuation in count, due to spots changing in appearance, disappearing, and also likely due to some human subjectivity in the counting process.  There now are no spots being recorded for the 9th, per the current plot:

210136521_1-9-20nospotsEISNcurrent.png.3072457d3fdb8a1391c4a5d6065d44f0.png

In actuality, spots presented themselves, in various number and size, over a period of more than 40 hours. They first appeared around noon UTC on the 8th, and were still presenting (faintly) after midnight on the 9th, as observed in the following imagery sequence:

2099712073_01-08at1200.png.7b0b8d113602869fabbb09383e10dbc5.png1262992845_01-09at000.thumb.png.2d041e596829772080c7e4b210cbff2b.png1836025487_01-09at1200.png.9e03e667edbbd16a44d0a87594bad3f6.png515975879_01-10at000.png.99a1c0c0ee7847f43330a29a33395216.png61843087_01-10at515.png.d99b9032505852c0e5203dccdbad458b.png

 

Here are my quick takeaways:

  1. Spot counting, in its current form (but more so in the past), is not an exact science and depends upon the location of the observers, and involves some human subjectivity.
  2. Any differences between the SILSO network or 'the other' professional network (NOAA/SWPC) are probably not that important to the bigger picture of what is trying to be accomplished.  Differences between the two may particularly show up, for example, when looking at the longest string of uninterrupted spotless days, but that is a relatively minor metric anyway.  
  3. Spot counting should eventually be done with computerized, image-analysis automation using satellite-based observatories (possibly backed up with ground-based observatories with reconciliation between the two) in order to get 24 hour coverage and remove human subjectivity from the process. The computerized system should be developed and proven over an interim period to compare and reconcile with the current process where humans are kept in-the-loop (like now with the SILSO network), in order to assure that they synch-up (within expected reason) in their count numbers, before solely relying upon the computerized system(s).  The computerized system(s) could track spots with much more useful and real-time detail and information (like size, magnetic intensity/complexity, etc.)
  • Like 2

Share this post


Link to post
Share on other sites

Hello,

Not barge in to an private conversation... but have been fascinated with this string (historically) and found the Svalgaard link invaluable in understanding the context of how the concept of "The Sunspot Number" has evolved. 

It seems there are different quantities worth measuring.  First just a pure number of Sunspots, but secondly the size (surface area) and cluster configuration of the various regions at any given time.  An automated counting system, such as theartist proposed is likely where data collection is headed.  I'm just imagining a situation where at one time there might be a dozen or more tiny (smaller than earth diameter) Sunspots present  on the earth facing surface Vs. another time when there is a gigantic single Sunspot whose dynamic energy release is orders of magnitude greater than the first example.  Obviously Sunspot Number is a surrogate marker for Solar Activity but not a precisely interchangeable one. Having looked over the Sunspot rating scales based on Size, Cluster Configuration etc. it begins to feel that historically the Group Number (GSN) attempts to preserve the continuity of information extending back to the end of Maunder, while the Wolfe Number (WSN) is offering a more detailed information set but only since 1849. 

Both have value and it seems there not be a simple way of reconciling the two and coming up with a unified count which merges the two while preserving the relevant information contained in each.

1182015460_TheNovitiate.thumb.png.0985445b5b6d55e016372b2ae053c45a.png

  • Like 2

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you also agree to our Terms of Use and our Privacy Policy.