A great great read on solar flare activity and comparisons to previous cycles!

[ChrisSmolinski]

"As solar activity ramps up (multiple X/near-X solar flares this week), we must be *cautious* on drawing comparisons to the last decade. If these flares happened 5 years ago, they wouldn’t have made it into the top flare category. A thread:

GOES-14 & 15 defined flares from 2010-2020, covering the previous solar maximum. However, upon launch of these satellites, a calibration discrepancy was discovered between GOES-14/15 and ALL prior GOES X-ray detectors, so old GOES-1 to 13 data were adjusted to account for this.

HOWEVER. Upon launch of GOES-16, it was announced that the older calibration had been correct (and GOES-14/15 were not). So in 2020, NOAA announced a recalibration to their dataset, increasing all prior flare classes by 42%!!! (Divide by 0.7). A massive change.

This huge difference CANNOT be understated. If this week’s X1 flares had happened before 2020, they’d have been categorised an M7 flare. In fact, a flare today would need to be X4.2, in order to have been called an X-flare just five years ago.

Taking this into account: we’ve had 31 X-class flares this solar cycle (since 2022). Under the previous calibration (used last solar cycle), we’d have only TWO(!!!). This is a MASSIVE discrepancy, that must be considered in qualitative and quantitative comparisons."

Full thread: https://twitter.com/RyanJFrench/status/1787108955065352197

[BoomboxDX]

Stands to reason. The new Solar uptick is welcomed, but it's not like 2012 at all. I'm not hearing it on my radios, and I hear hams on 20 M talking about the high bands being nowhere as good as they should be at this stage in the Cycle.

And then there is the gradually dropping eUV irradiance, which is what makes the ionosphere work. So the new cycle is great that it's here, and I'm glad that it's better than it was in 2019 when HF sounded like nuclear winter every other night, but it remains to be seen just how things will play out when this cycle actually peaks.