Category Archives: sunspot cycle

Exploring the Heliosphere

This is my new book for the general public about our sun and its many influences across the solar system. I have already written several books about space weather but not that specifically deal with the sun itself, so this book fills that gap.

We start at the mysterious core of the sun, follow its energies to the surface, then explore how its magnetism creates the beautiful corona, the solar wind and of course all the details of space weather and their nasty effects on humans and our technology.

I have sections that highlight the biggest storms that have upset our technology, and a discussion of the formation and evolution of our sun based on Hubble and Webb images of stars as they are forming. I go into detail about the interior of our sun and how it creates its magnetic fields on the surface. This is the year of the April 2024 total solar eclipse so I cover the shape and origin of the beautful solar corona, too. You will be an expert among your friends when the 2024 eclipse happens.

Unlike all other books, I also have a chapter about how teachers can use this information as part of their standards-based curriculum using the NASA Framework for Heliospheric Education. I even have a section about why our textbooks are typically 10 – 50 years out of date when discussinbg the sun.

For the amateur scientists and hobbyists among you, there is an entire chapter on how to build your own magnetometers for under $50 that will let you monitor how our planet is responsing to solar storms, which will become very common during the next few years.

Basic book details: 239 pages; 115 ilustrations; 6 tables; 70,000 words;

There hasn’t been a book like this in over a decade, so it is crammed with many new discoveries about our sun during the 21st century. Most books for the general public about the sun have actually been written in a style appropriate to college or even graduate students.

My book is designed to be understandable by my grandmother!

Generally, books on science do not sell very well, so this book is definitely written without much expectation for financial return on the effort. Most authors of popular science books make less than $500 in royalties. For those of you that do decide to get a copy, I think it will be a pleasurable experience in learning some remarkable things about our very own star! Please do remember to give a review of the book on the Amazon page. That would be a big help.

Yep…I want to get the e-book version ($5): Link to Amazon.

Yep…I want to get the paperback version ($15): Link to Amazon.

Oh…by the way…. I am a professional astronomer who has been working at NASA doing research, but also education and public outreach for over 20 years. Although I have published a number of books through brick-and-morter publishing houses, I love the immediacy of self-publishing on topics I am excited about, and seeing the result presented to the public within a month or two from the time I get the topic idea. I don’t have to go through the lengthy (month-year) tedium of pitching an idea to several publishers who are generally looking for self-help and murder mysteries. Popular science is NOT a category that publishers want to support, so that leaves me with the self-publishing option.

Other books you might like:

Exploring Space Weather with DIY Magnetometers. ($7). Link to Amazon.

History of Space Weather: From Babylon to the 21st Century. (paperback, $30) (ebook, $5). Link to Amazon.

Solar Storms and their Human Impacts (e-book; $2) Link to Amazon.

The 23rd CycleL Learning to live with a stormy star. – Out of print.

Sunspot Cycle Update!

Aurora over South Dakota on April 23, 2023 taken by Evan Ludes. https://spaceweathergallery2.com/indiv_upload.php?upload_id=195462

The spectacular solar storm we had on April 23, 2023 reminds us that, as the current sunspot cycle continues to progress, we will have many more of these spectacular aurora to look forward to in the next few years. So where are we in the current sunspot cycle?

Sunspot cycles average about 9 to 12 years, with the stronger cycles on the shorter end of this range and weaker cycles on the longer end of this range. The current cycle, Number 25, seems to be exceeding all forecasts for a weaker cycle and may in fact resemble previous ones like Cycle 22 or 23.

Solar Cycle Progression (Solar Cycle 24 – 25) – March 2023. Credit: NOAA/SWPX https://www.swpc.noaa.gov/products/solar-cycle-progression

The current cycle began in December 2019 and some predictions at that time suggested that it would probably be a very weak cycle perhaps not even exceeding Cycle 24. This is shown by the grey band in the above figure. Some even thought based on solar magnetic field data that we could be heading into another Maunder Minimum with no recognizble sunspots for the next 50 years. Instead, the rapid rise of activity and solar flares since 2020 has demonstrated that we still do not really understand what drives sunspot cycles.

This is rather embarrasing. The sunspot cycle is one of the most glaring features of the sun whose nearly constant period of 11 years begs to be explained. This is like meteorologists still not being able to explain why Earth has its four seasons.

The current sunspot cycle was born with the first spots sighted around April 2018 with spots that had the opposite polarity of those in Cycle 24. It is common for such spots to start appearing several years before the actual cycle commences. But by November 2019 this number had increased to two spots. In May 2020 the first M-class flare erupted, followed by the first X-class flare in July 2020.

Since 2020, the sunsppot counts and flare activity have consistently placed Cycle 25 on the upper tracks of the strong cycle forecasts being nearly 50% more active than the initial predictions year-by-year. Already by January and March 2023 we are seeing 143 and 122 sunspots which compares with the peak of 146 seen for Cycle 24. The red band in the figure below shows the current range of curves based on the most recent data. This places the trend for the maximum somewhere between Cycle 23 and Cycle 24. But the current year 2023 trends will probably give us the definitive predictions. So far, it looks like Cycle 25 will peak around early-2024.

This chart shows from lft to right the sunspot cycles 21,22,23 and 24. The last one on the right is the current cycle 25, with the original predicted number of sunspots, represented as the blue line. The green lines show the observed sunspots, which are trending toward the red line – the McIntosh et al. study – which predicts a higher number of sunspots. https://blogs.nasa.gov/solarcycle25/

So far, Cycle 25 is 40 months old. During this time we have already experienced 8 X-class flares on (X1) October 2, 2022, (X1.2) January 5, 2023, (X1.3) January 9, 2023, (X1) January 10, 2023, (X1.1) February 11, 2023, (X2.2) February 17, 2023, (X2.1) March 3, 2023, and (X1.2) March 29, 2023. Most of these appeared in 2023 so the pace of these major events is quickening.

Why is this important?

The sunspot cycle is a barometer of what we call space weather. Space weather is a term analogous to Earth weather with a number of parallels. Strong terrestrial winds are equivalent to the solar wind. Solar flares are equivalent to severe lightning storms, and coronal mass ejections are analogous to hurricanes and tornados. Just as severe Earth weather can cause billions of dollars of damage, severe space weather can damage satellites in Earth orbit, produce harmful radiation for astronauts working in space, and cause electric power grid outages. They also produce dramatic aurora!

The most recent examples of what space weather can do is the loss of 40 Starlink satellites on February 3, 2022 costing SpaceX over $100 million. The cause was a space weather event that heated up Earth’s outer atmosphere causing it to expand into space and provide extra drag to the satellites in Low Earth Orbit. The satellites tried to compensate by firing their thrusters but quickly used up all their propellant and burned up in the atmosphere.

Meanwhile, the European Space Agency’s Swarm satellites are having their own problems. Launched in 2013, these satellites measure and map Earth’s magnetic field. By July 2022 the satellites in the three-satellite constellation have been falling by up to 20 km per year from their initial orbit of 450-530 km.

How stormy can it get?

Frequency of geomagnetic events stronger than Kp=6 (blue) Kp=7 (red) and Kp=8 (black) averaged over the recent ‘strong’ sunspot cycles by the year of the cycle. Sunspot Maximum occurs near Years 5-6.

The graph shows how disturbed Earth’s magnetic field is during various years throughout the sunspot cycle. It is based on the average activity from the past three cycles. The black line gives the average number of extreme storms with Kp > 8 that produce aurora seen as far south as southern California or Florida like the recent one on April 23, 2023. The red line is storms stronger tha Kp = 7, and the blue line is storms stronger then Kp=6. These still produce brilliant aurora, but generally only seen in the northern-tier states of the United States and in New England and Alaska.

We are now in Year 4 of the current sunspot cycle with a maximum that may be between Year 5-6 in 2024-2025, so we should expect that most of the aurora activity is still in our future, peaking sometime between Year 7 and 9, which is about 2026-2028. It all depends on how the sunspot numbers play out this year and in 2024, but for aurora lovers, the best is yet to come!