Goes-16 and Goes-17

[abc]

I noticed that the goes-17 data is back about 2 weeks ago, but it gives a slighly different reading as that from goes-16. What is the reason causing such a phenomenon and which one will we base on if we have to rate a solar flare.

[Newbie]

GOES 16 Long Data (the red line on the GOES X-ray Flux graph) NOAA, has been absent for 3 weeks the same time as GOES 17 Long and Short Data appeared on the graph. The status of GOES 16 and 17 showed nothing unusual. The latest solar flares have been rated according to GOES 17 Long values, the orange line, as far as I can tell but may not be the case.

I have also been wondering why this happened. 

 

Edited August 30, 2021 by Newbie

[abc]

However, I observed that most of the flares are rated based o goes-16 long values

[helios]

I assume you mean the x-ray flux.

GOES-16 and 17 seem to match very well in the "long" wavelength (0.1 to 0.8 nm) which is used for the ABCMX-Classes. So there should be no difference to be expected.

The "short" wavelength (0.05 to 0.4 nm) does also seem to match well above about 10^-7 W/m².
I believe the difference below 10^-7 W/m² is coming from the electron contamination correction algorithm, which is active on 17 but not on 16. But is only relevant on very low flux.



Noteworthy is however, that the GOES-16/17 x-ray readings are about 30% higher than those from earlier satellites:
https://www.swpc.noaa.gov/sites/default/files/images/GOES 16 XRS Updates and Status.pdf

Edited August 30, 2021 by helios

[Newbie]

ABC: Where did you find the GOES 16 values The graph that Helios just posted doesn't show GOES 16 long.

Edited August 30, 2021 by Newbie

[abc]

I mean, for example, when the x-ray flux for a solar flare is C7.8 for Goes-16 but C8.0 for Goes-17, which one will be the final rating

[helios]

As far as I know, 16 was always available.
https://www.swpc.noaa.gov/products/goes-x-ray-flux

@abcOn which flare did you saw that difference? Usually the difference is much smaller.
If in doubt, I would use the "primary" source, which is currently 16.
https://services.swpc.noaa.gov/json/goes/instrument-sources.json

Edited August 30, 2021 by helios

[Newbie]

Helios the red line is not always apparent from what I'm looking at. Time for an upgrade?

[helios]

@NewbiePerhaps because it is overlapping with 17. If you turn off 17 by clicking on the legend, 16 is always visible.

[abc]

@NewbieYou can use your mouse and mouse over a random point and you will see there are different figures

[Newbie]

I've been looking at the GOES X-ray flux for years. I have only been concerned with the value for current flux and latest solar flare flux in the table.

Thanks helios and abc, you are right, I did know you could get data for individual points on the graph but I thought 16 long data had ceased.

I see your dilemma abc however the table underneath the graph provides the GOES16 latest x-ray event 1-8 A flux, that's the figure I would use for the size of the flare. 

I'm so glad this got sorted, thanks again for posting this abc Thanks again for your input Helios

1 hour ago, helios said:

On which flare did you saw that difference? Usually the difference is much smaller.
If in doubt, I would use the "primary" source, which is currently 16.
https://services.swpc.noaa.gov/json/goes/instrument-sources.json

This is quite a discrepancy, the 16 long and 17 long lines have been so close to one another lately I couldn't tell them apart. Their values would be almost identical. 

So it's true then that the latest satellites report higher flux than the earlier ones and by 30%, that's quite a difference.

Edited August 30, 2021 by Newbie

[abc]

I'd like to know why the goes-16 and goes-17 break down by turn. Will a flare be recognised if the goes-16 break down, e.g. the c5 falre today

[Vancanneyt Sander]

It’s eclipse season, the satellites don’t break down:

GOES satellites encounter two periods during the year in which they are in Earth's shadow. Known as the Eclipse (ECL) season, these periods require the spacecraft to be completely dependent upon batteries for a maximum of 72 minutes daily. Eclipses occur approximately from late February to mid-April, and from late August to mid-October.

due to the eclipse, the X-ray reading drops and will return when eclipse is over.

PS: GOES-17 is the backup satellite which wasn’t in eclipse phase so there is always a reading

[abc]

but why dont the data fall previously

 

oh so does goes 17 appear during the eclipse season? and for other times they dont right?

[Vancanneyt Sander]

if you look at the archive of the past few weeks you'll notice that there were several dropouts because of the eclipse season. As stated in my post it lasts from late august to mid-october 😉 . GOES-17 is the secondary satellite that monitors X-rays, so if there was an issue or an eclipse on GOES-16 there would still be data to monitor the X-rays. 

[Christopher S.]

This is really simple. No sun means no power. The backup satellite is just providing data for the other while it conserves power. There is no magical or strange force altering which satellite is delivering your data, it just depends on the time of year and the eclipse season.

[Kaimbridge]

19 hours ago, abc said:

oh so does goes 17 appear during the eclipse season? and for other times they dont right?

No, GOES-17 is the brand new secondary/backup to GOES-16, the primary source (in the same way that GOES-14 was the secondary/backup to the primary GOES-15 satellite)!

BTW, is SWPC’s website in maintenance mode tonight (even the last day or so)??

Most of the data pages keep bouncing around between midday Sept.16 and now!?!

[Christopher S.]

2 hours ago, Kaimbridge said:

Most of the data pages keep bouncing around between midday Sept.16 and now!?!

This is not unusual when poking around in code or changing things with the web API. Their IT person might need some sleep and a strong cup of coffee in the morning.

[helios]

18 hours ago, Kaimbridge said:

Most of the data pages keep bouncing around between midday Sept.16 and now!?!