Showing posts with label Sunspot minimum. Show all posts
Showing posts with label Sunspot minimum. Show all posts

Thursday, September 17, 2020

Solar Cycle 25 has officially begun


At a press conference on Tuesday the 15th of September 2020, scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA) announced that Solar Cycle 25 has officially begun and the actual sunspot minimum between cycles 24 and 25 had occurred in December of 2019. In a previous press release  in December of 2019, the panel of scientists had predicted that the minimum would occur during a period stretching from October 2019 to October 2020 i.e. April 2020 +/- 6 months.

As with all sunspot cycles, it's only several months after the minimum that scientists can look back and be sure of when it occurred. There was however some signs that we had passed the peak as there was an increase in the number of sunspots which had spotted recently with the correct polarity for cycle 25.

Ultra-violet image of the sun at the sunspot minimum

The next sunspot maximum is predicted to occur in the middle of 2025 and the peak is expected to be the same in intensity as Cycle 24.

What does all this mean??? ... In the short term, not a lot will change. For stations in northern latitudes, the upper HF bands of 15m, 12m and 10m will struggle to open and when they do, it will tend to be over North-South paths.

In the second half of 2021, things should start improving and by 2022, we should start seeing more openings on East-West paths.

By 2025, we should see worldwide openings on 28 MHz but the 50 MHz band is unlikely to be as spectacular as say Cycles 22 and 23 back in 1989 and 2001. At the sunspot peak, there will probably be plenty of North-South openings on the 6 metre band but the multi-hop openings East-West may be more of an issue.

Digital Modes ... It's very likely that Sunspot Cycle 25 will be the first one where digital modes like FT8 will dominate. This may well  allow some propagation paths to appear that may not have been so obvious on SSB or CW. Interesting times ahead.

Wednesday, November 26, 2008

Not a spot to be seen....

Here is a picture of the Sun today....not a single spotspot to be seen. We are still well and truely at solar minimum.

For the record, the solar flux reading for today is 68. Not really up or down....about the same as before.
In a recent ARRL e-mail, W7TJ wrote..."I have been on the air 44 years, and never have I seen a cycle with such a long extended bottom. Usually the bottom is brief, maybe 6-9 Months of low Sunspot numbers and Solar Flux Values in the Mid 60s. The rise and fall is and has historically been short. Looking back (depending on where one measures) there is a very long and stretched bottom spanning 1 1/2 to 2 years. Graphically instead of a "V" we have a "U" with a long flat bottom."