Solar and Aurora Activity Chat

[Don]

4 hours ago, Weather-history said:

Squeeze em!!

[JeffC]

Observed Flux Density 70.8

Adjusted Flux Density 72.9 = low

 

[Uncle_Barty]

On 27/04/2020 at 21:55, JeffC said:

Can we say we've not yet reached absolute minimum?

I had a thread running on the other place on the progress of Solar Cycle 24/25 but that thread has now been deleted by the look of things.

We will know for sure in six to twelve months. But I believe from current data that the minimum will have turned out to have been during the 4th quarter of last year.

Solar flux-wise, we had some very low readings for a period beginning about now this time last year. With solar flux levels just starting to edge up now in response to a slowly increasing number of sunspot groups, these low values will start to drop out of the reckoning, and unless there is a slump in SFI to a very low level in the next few weeks, the smoothed 12-month mean solar flux will have turned out to reach a minimum of 69.14 in mid-November last year. This annual value centred on December 7th is now up to 69.22.

As for sunspots, the statistical minimum looks likely to be December 2019. This could be brought forward to November 2019 if June's sunspot number reaches 11.. not completely out of the question as we are definitely seeing an increase in Cycle 25 groups. We shall see!

As I mentioned in the other place, there is a sizable school of thought that we are entering a Grand/Dalton/Maunder minimum period.

I think this is most unlikely, and the upcoming cycle will be similar in size to the last one (quite a weak maximum) or perhaps a little stronger. My basis for this is the strength of the sun's polar magnetic field at the time of solar minimum. There is a graph here: https://solen.info/solar/polarfields/polar.html

There is a clear correlation between the strength of the polar magnetic field at solar min and the size of the succeeding solar max.

[JeffC]

Observed Flux Density 72.5

Adjusted Flux Density 74.7 = low

[JeffC]

Observed Flux Density 71.0

Adjusted Flux Density 73.2 =low

[Weather-history]

8th June

[JeffC]

16 hours ago, Weather-history said:

8th June

Bugger!

[JeffC]

Observed Flux Density 72.4

Adjusted Flux Density 74.6 = low

[JeffC]

Observed Flux Density 71.0

Adjusted Flux Density 73.2 = low

[JeffC]

Observed Flux Density 72.4

Adjusted Flux Density 74.6 = low

[JeffC]

Observed Flux Density 71.1

Adjusted Flux Density  73.3 =low

[JeffC]

Observed Flux Density 70.2

Adjusted Flux Density 72.4 = low

[JeffC]

Observed Flux Density 70.6

Adjusted Flux Density 72.9 = low

[JeffC]

Observed Flux Density 70.4

Adjusted Flux Density 72.6 = low

[JeffC]

Observed Flux Density 70.0

Adjusted Flux Density 72.3 = low

[SteveB]

1 day blank,  123 for 2020, 73%

Solar flux 69

Thermosphere: 2.77

[JeffC]

Observed Flux Density 69.2

Adjusted Flux Density 71.5 = low

[Katrine Basso]

Daily Sun: 18 Jun 20

Sunspot number: 0

Updated 18 Jun 2020

Current Stretch: 2 days
2020 total: 124 days (73%)

Thermosphere Climate Index
today: 2.81x1010 W Cold

Updated 17 Jun 2020

The Radio Sun
10.7 cm flux: 69 sfu

 

[JeffC]

Observed Flux Density 67.9

Adjusted Flux Density 70.2 = low

[SteveB]

3 days blank,  125 for 2020, 73%

Solar flux 68

Thermosphere: 2.79

[JeffC]

Observed Flux Density 68.6

Adjusted Flux Density 70.8 = low

[SteveB]

4 days blank,  126 for 2020, 73%

Solar flux 69

Thermosphere: 2.79

[JeffC]

Observed Flux Density 68.2

Adjusted Flux Density 70.4 = low

[SteveB]

5 days blank, 127 for 2020, 73%

Solar flux 68

Thermosphere: 2.68

[JeffC]

Observed Flux Density 67.6

Adjusted Flux Density 69.9 = very low