Jump to content

Now "official" Solar-Cycle 25 started in December 2019

Ron NL

Recommended Posts



Obviously the accuracy is not more then a month ... since they dont mention a date 

And here we go again ...what is the definition of Start or End of a solar-cycle ? 

* 1  Is it at the beginning of the flat part in the minimal activity ?

* 2  Is it in the middle of the flat part in the minimal activity ?

* 3  Is it at the end of the flat part in the minimal activity ?  


The problem might be that a good definition of Solar-Activity dont exist ? 

I myself define the start of a new cycle ... as the point where it starts to go up again 

in other words option * 3 the end of the flat part in the minimal activity ?   

I chose that option because i study the effects of the Solar-activity on Life-on-Earth  

I found that during a long period of minimal solar-activity ..there is not much changes going on in Life-on-Earth 

But as soon as it comes out of the flat part .... it suddenly has large effects on Life-on-Earth

We just had a very clear demonstration of that ... Pandemic started at 21 December 2019 ! ( exactly @ winter-solstice)  


So who is right ?

Can we define an exact start/end ?  ... it's obviously a question of interpretation ...and what it is used for ? 




Edited by Ron NL
Link to comment
Share on other sites

There is some interesting data showing up in the figures on the Thermosphere Climate Index; if we compare this time last year with the present date we can see a significant fall-off : -

1st/2nd/3rd Sept last year show as :


9.0000000-1.0000000-2019.0000   3.4374996e+10

9.0000000-2.0000000-2019.0000   3.7616951e+10

9.0000000-3.0000000-2019.0000   3.9029051e+10

13th /14th/15th Sept as :

9.0000000-13.000000-2019.0000   4.0240857e+10

9.0000000-14.000000-2019.0000   4.0589930e+10

9.0000000-15.000000-2019.0000   4.1055056e+10

This year we have, for the same periods:

9.0000000-1.0000000-2020.0000   3.3142835e+10

9.0000000-2.0000000-2020.0000   3.4014414e+10

9.0000000-3.0000000-2020.0000   3.4282003e+10


9.0000000-12.000000-2020.0000   3.4369407e+10

9.0000000-13.000000-2020.0000   3.4152653e+10

9.0000000-14.000000-2020.0000   3.4118711e+10

- A significant cooling. I have predicted that end of October should be around 4.9; this may be a significant overestimation ! But as I have said, time can blow holes in the best of estimations ! What are your thoughts?



Link to comment
Share on other sites

The start of the next Solar Cycle is indicated by an uptick in Solar Activity and Solar Flux. In other words, the beginning of the upswing of Solar Flux on most charts that you can find on the internet.

All of your claims about the effect of this, and the errors involved with conventional measurements, are unsubstantiated and outright false.

  • Like 1
Link to comment
Share on other sites



an uptick in Solar Activity and Solar Flux


Yes that is what im saying  ... new cycle starts when activity comes out of the flat part   (at the corner of this  _/  )                     

So we agree on that 


The rest of your reply ... im not going to discuss that again. 







Edited by Ron NL
Link to comment
Share on other sites

I think this is a great question and to be honest I am not 100% sure. I tried reading the press releases but cant really find a clear answer. Does solar minimum signal the start of SC25 and is thus December 2019 the first month of SC25 or does December 2019 still belong to SC24? I assume SC25 did start in Dec 2019. @Vancanneyt Sander

...and yes... @The Atmosphere Guy... please try to avoid going off topic in other people's threads. If you want to start a relevant discussion about something its better you start your own thread.

EDIT: Nevermind, the press release from the SIDC clearly states that December 2019 is the starting point of SC25.

Edited by Marcel de Bont
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • 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.