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Kaimbridge

Discrepancy In X-Ray Data?

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On the Solar activity link for 2017-Jan-16, it lists two B-class flares for the day, a B1.3 @01:44 and a B1.4 @18:23, both of which match SWPCʼs Solar Events page for Jan 16.

However, while if you hover over 01:44 on that dayʼs flare graph, it shows B1.31, when you hover over 18:23, it gives a B1.99, both of which match the values for the time slots on the 1-minute X-ray flux text page for Jan 16!

When you look at the graph, it is obvious that B1.99 is the correct value:  chart-1.jpegWhy the discrepancy?

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Hi @Kaimbridge

Looks like you caught NOAA on a mistake ;). It isn't the first time NOAA classifies flares with faulty strength, we've done multiple corrections in the past for the M1+ solar flares where there was difference in the GOES data and the SWPC logs and those where corrected by us in our databases to make sure we have the correct values. We have now edited the flare so it will display correctly, thx for reporting!

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Thatʼs what I figured.  P=)

On a related note, why do they tend to round flare/flux levels down—e.g., “C3.28” “C3.2”, “X1.79” “X1.7” “X1”—rather than to the nearest (in these examples, it should be “C3.3” and “X1.8” “X2”)?

This doesnʼt seem to be an occasional error, but intended policy:  Is there a valid reason for this?

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It's a good question that we also don't have an answer for. SWPC apparently has an policy to round flares always off to the lower value. In normal math an X1.99 would be X2 but SWPC will always say it was a X1.9. Maybe they do this intentionally to prevent that an M9.97 would be classified as an X1

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17AP26W-SolarImage.thumb.png.8300f7c63f3b0bed1b6866fb48fadff9.png

Is there a reason that the largest flare of the day is maxed as B4.5 at 17:48 (rather than B4.9 or B4.8, as the chart shows it should be at that time?), and not B5.0 or B4.9 at 17:50 as appears to be the case?  Or is this another “NOAA mistake”? ?  ?

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NOAA often rounds off solar flares like M3.38 as M3.3 but this looks like it's an error of NOAA that marked the peak a bit too early, guess that NOAA had a rough day ;)

PS.: that screenshot looks like our site, but yet the color scheme is different ??

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23 hours ago, Vancanneyt Sander said:

PS.: that screenshot looks like our site, but yet the color scheme is different 1f914.png1f603.png

Thatʼs because it is your site ?—I took three screenshots and combined the relevant parts into one concise shot (flipping the bottom line of the 17:50 flare bubble)!  ?

As for the color scheme, yes, I use the inverse white on black. as it is easier on the eyes.  ?

BTW, by including the full flare spectrum up to the unthinkable X100, you eliminated the “Reset Zoom” getting in the way of the flare bubbles!  ?

A suggestion:  Why not add dim colors to the C, B and A chart ranges, too—say, something like light aqua blue (#8FFFFF) for Cs, light lime green (#B0FF50) for Bs and light gray (#D2D2D2) for As—or, at the very least, darken the B and C boundary lines?  ?

 

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Op 2017-4-28 om 05:32, Kaimbridge zei:

Is there a reason that the largest flare of the day is maxed as B4.5 at 17:48 (rather than B4.9 or B4.8, as the chart shows it should be at that time?), and not B5.0 or B4.9 at 17:50 as appears to be the case?  Or is this another “NOAA mistake”? 1f60c.png  1f603.png

I looked at the events file of April 26 and it is not a mistake. The thing is, for some reason they took the peak value as measured by GOES 13 for that event, instead of GOES 15. The X-ray data in the archive is only the data from the primary satellite which is GOES 15 right now. Why they took the data from GOES 13 while GOES 15 was up and running at the time of the event is a mystery for me.

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 chart.thumb.jpeg.0040489a97adce0759c829e6e3905332.jpeg

Solar flares

Region   Start Maximum End
2690  B1.0   03:20  03:23    03:28
       
         

Well, looks like they decided to use the secondary data:

Quote

   ftp://ftp.swpc.noaa.gov/pub/lists/xray/20171207_Gp_xr_1m.txt


> 2017 12 07  0322   58094  12120     8.52e-09    8.60e-08
> 2017 12 07  0323   58094  12180     1.05e-08    8.84e-08
> 2017 12 07  0324   58094  12240     1.04e-08    9.00e-08
> 2017 12 07  0325   58094  12300     1.03e-08    8.95e-08

 
Quote

ftp://ftp.swpc.noaa.gov/pub/lists/xray/20171207_Gs_xr_1m.txt

> 2017 12 07  0322   58094  12120     1.58e-08    8.83e-08

> 2017 12 07  0323   58094  12180     1.56e-08    1.00e-07

> 2017 12 07  0324   58094  12240     1.61e-08    9.49e-08

> 2017 12 07  0325   58094  12300     1.78e-08    9.97e-08

  

 

Edited by Kaimbridge
Formatting (Any way to edit in source code mode?)

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We've seen this before too and don't really understand why NOAA suddenly uses secondary data instead of their primary source. Normally if there are troubles with primary data, it is announced that they would switch to secondary but when solar flare strengths are added we'll get situations like this. Sometimes NOAA isn't really correct ;) .

PS.: Source mode is not available for safety reasons (if a spammer gets through, it could do plenty of things wrong with html injection ;) )

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6 hours ago, Vancanneyt Sander said:

PS.: Source mode is not available for safety reasons (if a spammer gets through, it could do plenty of things wrong with html injection ;) )

Well, canʼt you just allow the tags that are used above (I donʼt mean total source code, just the ones to be able to manually do the functions above:  The automatic WYSIWYG posting can be difficult to edit/delete...such as when I pasted the solar flare quote below the image above a second time and then tried to delete it—the contents deleted, but not the table it posted it in, itself)?

BTW, how come no archives for the past two days—is that your doing or NOAAʼs (I know their ftp server seems to be down)?

Edited by Kaimbridge
Added archive question

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23 uren geleden, Kaimbridge zei:

Well, canʼt you just allow the tags that are used above

In the software we use html-tag limitation is not available, the creator found that the most users have enough with a WYSIWYG editor. So out of safety, we don't enable it by default.

23 uren geleden, Kaimbridge zei:

BTW, how come no archives for the past two days—is that your doing or NOAAʼs (I know their ftp server seems to be down)?

Archive of the last few days is available. Due note that after midnight not all options are available but are added during the night when NOAA updates their stuff. 

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5 hours ago, Vancanneyt Sander said:

Archive of the last few days is available. Due note that after midnight not all options are available but are added during the night when NOAA updates their stuff. 

Yeah, the Dec.9 archive showed up sometime yesterday afternoon (EST)...but the Dec.8 archive is still missing.  P=|

Okay, it is there now (did you just do something, or was it only coincidence? P=).

Edited by Kaimbridge
Updated

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Well, SWPC appears at it again: For the past three days they have been graphing GOES‐15 data, but quoting GOES‐14 flare values (yesterday—Fri.25th—they listed the peak flare as B1.2 @ 2222z, which was GOES‐14...GOES‐15 peaked then at A7.1, as your moving “bubble cloud” tracer graph properly listed—though the blackline flare data is GOES‐14ʼs B1.2!
So, if it continues today, the 1322z flare will rightfully show “C5.02” (GOES‐15) with the “bubble cloud”, but the blackline of the flare will give GOES‐14ʼs “C4.73”!  P=/

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7 hours ago, Vancanneyt Sander said:

Yes, we've noticed this too and made a fix to prevent this. Hopefully some new flares to see if it's all ok now ;) 

Yup, I see the corrected Saturday values (though Wed-Fri is still jumbled,

too! P=| ).

 

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