Posts Tagged ‘sunspots’

Sunspot Numbering System Revised

Although sunspot data has been recorded in one form or another for over 400 years, there have been few changes in the counting system since the introduction of the 'Wolf Number' in 1849. Recording of the sunspot 'Group Number' came into existence in 1998. It seems there were some strong differences in the two parallel series of systems and in 2011 a group of 40 experts undertook a full examination and revision of both systems in order to identify and fix the defects.

The new system, which became effective on July 1st, has brought both systems into alignment, with the most notable correction being in the lowering, by about 18%, of all numbers after 1947. The new Group Number has been corrected for a large underestimate of all values before the 20th century and has resulted in a fully reconstructed series of Group Numbers.

Viewed graphically, through my non-expert eyes, most of the earlier cycles up until 1947 appear to show slightly stronger peaks than before while those after 1947, including monster Cycle 19, show smaller peaks.

The graphic of Group Numbers shows significant increases for cycles up until the 1900's.


The new system brings the correlation of Group Numbers and Sunspot Numbers into harmony, unlike before.


Although these changes became effective on July 1st, the work is far from complete. According to the folks at SILSO (Sunspot Index and Long-term Solar Observations):

Still, as can be seen, significant deviations remain, mainly before 1825, when the observations become scarce and in periods of activity minima (low counts). So, more work definitely remains to be done for many years to come, but given the major improvements harvested at this stage, the WDC - SILSO is now going to proceed with the public release of this new version.

The preparation of this major operation is now almost completed. It required a huge organizational and programming work from the small SILSO team. Indeed, the release of the new past Sunspot series is just a starting point for the WDC-SILSO. Indeed, it requires a deep reworking of the operational software that will process the data from our worldwide network on July 1st and in the future. Indeed, various data products must be made seamlessly compatible with the new base total Sunspot Number series: the hemispheric Sunspot Numbers, the daily Estimated Sunspot Number, the 12-month solar-cycle forecasts, all data plots and the derivation of personal k coefficients for all stations of the network.

After a rather uneventful life over the past 166 years, the Sunspot Number will thus be reborn in a new incarnation on Wednesday July 1st. We hope that the science community will welcome this revived data set and will appreciate the considerable community effort accomplished over the past four years to produce a better reference for long-term solar and Sun-Earth studies.

New Sunspot Region: Flare Activity Expected This Week

There is a new sunspot region rotating into view, producing moderately-strong (M-class) x-ray flares. This video shows you the first 11 hours of May 5, 2015

Expect flares throughout this week, which will degrade HF propagation DURING the flare, but enhance propagation overall (due to the higher Radio Flux). There might be occasional coronal mass ejections, too.

Watch stunning highlights, last 5 years of the Sun

We rely on the Sun for HF radio communication propagation. For the last five years, we have an amazing front-row seat: the SDO spacecraft. Here is a video with highlights of the last five years of solar activity as seen by NASA and the SDO AIA spacecraft. This is worth seeing on a larger monitor, so try to view it full screen on something larger than your palm. The music is pretty good too. It is worth the 20-some minutes of stunning viewing. Be sure to share!




This video features stunning clips of the Sun, captured by SDO from each of the five years since SDO’s deployment in 2010. In this movie, watch giant clouds of solar material hurled out into space, the dance of giant loops hovering in the corona, and huge sunspots growing and shrinking on the Sun’s surface.

April 21, 2015 marks the five-year anniversary of the Solar Dynamics Observatory (SDO) First Light press conference, where NASA revealed the first images taken by the spacecraft. Since then, SDO has captured amazingly stunning super-high-definition images in multiple wavelengths, revealing new science, and captivating views.

February 11, 2015 marks five years in space for NASA’s Solar Dynamics Observatory, which provides incredibly detailed images of the whole Sun 24 hours a day. February 11, 2010, was the day on which NASA launched an unprecedented solar observatory into space. The Solar Dynamics Observatory (SDO) flew up on an Atlas V rocket, carrying instruments that scientists hoped would revolutionize observations of the Sun.

Capturing an image more than once per second, SDO has provided an unprecedentedly clear picture of how massive explosions on the Sun grow and erupt. The imagery is also captivating, allowing one to watch the constant ballet of solar material through the sun’s atmosphere, the corona.

The imagery in this “highlight reel” provide us with examples of the kind of data that SDO provides to scientists. By watching the sun in different wavelengths (and therefore different temperatures, each “seen” at a particular wavelength that is invisible to the unaided eye) scientists can watch how material courses through the corona. SDO captures images of the Sun in 10 different wavelengths, each of which helps highlight a different temperature of solar material. Different temperatures can, in turn, show specific structures on the Sun such as solar flares or coronal loops, and help reveal what causes eruptions on the Sun, what heats the Sun’s atmosphere up to 1,000 times hotter than its surface, and why the Sun’s magnetic fields are constantly on the move.

Coronal loops are streams of solar material traveling up and down looping magnetic field lines). Solar flares are bursts of light, energy and X-rays. They can occur by themselves or can be accompanied by what’s called a coronal mass ejection, or CME, in which a giant cloud of solar material erupts off the Sun, achieves escape velocity and heads off into space.

This movie shows examples of x-ray flares, coronal mass ejections, prominence eruptions when masses of solar material leap off the Sun, much like CMEs. The movie also shows sunspot groups on the solar surface. One of these sunspot groups, a magnetically strong and complex region appearing in mid-January 2014, was one of the largest in nine years as well as a torrent of intense solar flares. In this case, the Sun produced only flares and no CMEs, which, while not unheard of, is somewhat unusual for flares of that size. Scientists are looking at that data now to see if they can determine what circumstances might have led to flares eruptions alone.

Scientists study these images to better understand the complex electromagnetic system causing the constant movement on the sun, which can ultimately have an effect closer to Earth, too: Flares and another type of solar explosion called coronal mass ejections can sometimes disrupt technology in space as well as on Earth (disrupting shortwave communication, stressing power grids, and more). Additionally, studying our closest star is one way of learning about other stars in the galaxy.

Goddard built, operates and manages the SDO spacecraft for NASA’s Science Mission Directorate in Washington, D.C. SDO is the first mission of NASA’s Living with a Star Program. The program’s goal is to develop the scientific understanding necessary to address those aspects of the sun-Earth system that directly affect our lives and society.

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Music Via YouTube “Free-for-use” Creation Tools

Video clips of the Sun are from NASA’s Goddard Space Flight Center/SDO which are in the Public Domain

By the way, this is an example of what I am trying to produce on a more regular basis, once I launch the space weather YouTube channel that I have started. If you wish to help, here is the GoFundMe link:


Solar Plasma Filament Eruption – The Sun – November 6,7 2013

The Sun currently is active, with powerful, complex magnetic structures that have formed a healthy number of sunspots. We are seeing a fair number of x-ray flares, which push the 10.7-cm flux higher than we’ve seen in a while.

Sunspots and flares means better propagation in general, especially on the higher frequencies of the shortwave spectrum.  While a flare can cause a short period of “blackout” conditions (especially on the lower frequencies) on the sunlit side of the Earth, such activity is part of the positive activity that ionizes the F-region, providing for DX.

Here’s a movie of one such flare and the release of solar plasma, a release known as a coronal mass ejection (CME): At about midnight, UTC, on 6 November 2013, a moderately-strong M-class flare erupted, with a “beautiful” CME:


We will see continued flare activity over the weekend, so expect great conditions on the HF bands, with momentary blackouts.  Keep up to the minute on space weather at

73 – de NW7US
Propagation Columnist, CQ Communications Magazine, Popular Communications Magazine

Our little sliver of time

All the news sources–I saw it on Yahoo!, of all places–are churning out stories today about the current state of the surface of the sun. Three different “experts” have issued dire predictions about the sleepy sun and what it means for mankind…and not just us hams, who enjoy bouncing signals off an ionized atmosphere.

You know as well as I do that simply saying this cycle is slow to develop is not going to attract much reader interest. But if you say there is the possibility that the dormancy of Ole Sol portends historic implications, that it could reverse the effects of that evil, man-made global warming (or make it even more dire), that there could be unknown but potentially catastrophic weather events as a result…heck, even that we are on the verge of another Maunder Minimum, when the sun went to sleep for 300 years and we entered a “mini-Ice Age!”…then you will get some attention. Attention to your columns, your websites, your blogs, your books, your speeches.

I know it is human nature to see things from a very narrow perspective. Understanding things like climate change that usually take eons to be obvious and drawing conclusions about variations in sunspot minima and maxima that only occur in eleven-year cycles are difficult for us mortals to do. Geologic time and cosmologic time and distance are impossible for us to comprehend in our simple little seven- or eight-decade life spans. That’s why all the junk about rapid climate change (which I consider normal weather variation and based on decidedly short-term data) has found so many who are willing to swallow it, hook, line and sinker.

I admit I know little about sunspots or solar weather, beyond the fact that more spots equal better propagation on the high-frequency radio bands and pretty displays of the Northern Lights. And I appreciate data and scientific observation. But seems to me that it is far too early to say the sun is going to be dozing for the next three centuries simply because cycle 24 is a tad bit slow to get moving. After all, many of these same “experts” were touting what an active cycle this was going to be…and they were doing it only a year or so ago.

Reminds me of the high-tech “weather rock” my wife has in her flower garden. “If this rock is wet, it is raining. If it is dry, it is sunny. If it is white, it is snowing.”

I’m still hoping for an active solar cycle. I have somehow managed to be inactive in my amateur radio activities during each of the past two cycle maxima, and I had high hopes for that “arm-chair” ragchew with the Far East on 10 meters in the middle of the day. But if it doesn’t measure up, so be it. I talked to plenty of guys all over the world at the yawning chasm between the peaks, after all.

But most of all, I’d like to see everyone calm down a bit and not be so myopic. We see only a tiny slice of time in our own existence. Even so-called scientific observations are looking at a pitifully narrow slab of time and only a tiny bit of reliable data.

Put it into perspective before you panic and sell all your ham gear. Or before you stop gazing northward for a glimpse of the aurora borealis.

By the way, I checked. There is nothing we can do about the state of the sun’s surface anyway, so why worry?

Don N4KC

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