Posts Tagged ‘sunspot cycle’
Thirty Minutes of Dazzle: The Sun in UHD 4K by SDO (NASA)
Take a front-seat view of the Sun in this 30-minute ultra-high definition movie in which NASA SDO gives us a stunning look at our nearest star.
This movie provides a 30-minute window to the Sun as seen by NASA’s Solar Dynamics Observatory (SDO), which measures the irradiance of the Sun that produces the ionosphere. SDO also measures the sources of that radiation and how they evolve.
SDO’s Atmospheric Imaging Assembly (AIA) captures a shot of the sun every 12 seconds in 10 different wavelengths. The images shown here are based on a wavelength of 171 angstroms, which is in the extreme ultraviolet range and shows solar material at around 600,000 Kelvin (about 1 million degrees F.) In this wavelength it is easy to see the sun’s 25-day rotation.
The distance between the SDO spacecraft and the sun varies over time. The image is, however, remarkably consistent and stable despite the fact that SDO orbits Earth at 6,876 mph and the Earth orbits the sun at 67,062 miles per hour.
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. Moreover, studying our closest star is one way of learning about other stars in the galaxy. NASA’s Goddard Space Flight Center in Greenbelt, Maryland. built, operates, and manages the SDO spacecraft for NASA’s Science Mission Directorate in Washington, D.C.
Charged particles are created in our atmosphere by the intense X-rays produced by a solar flare. The solar wind, a continuous stream of plasma (charged particles), leaves the Sun and fills the solar system with charged particles and magnetic field. There are times when the Sun also releases billions of tons of plasma in what are called coronal mass ejections. When these enormous clouds of material or bright flashes of X-rays hit the Earth they change the upper atmosphere. It is changes like these that make space weather interesting.
Sit back and enjoy this half-hour 4k video of our Star! Then, share. 🙂
73 dit dit
Five X-class (Major) X-ray Flares in a Row (plus more!)
Well, thankfully, this is not happening during this contest weekend: one of the largest sunspot regions during this Sunspot Cycle 24, and one of the biggest in several decades, gave us quite a show, back in October 2014.
Five major X-class (very strong) and a number of moderate and “mild” solar x-ray flares erupted from a single sunspot region – this video covers the time period of October 19-27, 2014, as captured by NASA’s SDO spacecraft. This is from what has been one of the biggest sunspot regions in a number of decades.
Between October 19 and October 27, 2014, a particularly large active region on the Sun dispatched many intense x-ray flares. This region, labeled by NOAA as Active Region (AR) number 12192 (or, simply, NOAA AR 12192, and shortened as AR 2192), is the largest in 24 years (at that point in Solar Cycle 24).
The various video segments track this sunspot region during this period (Oct. 19 – Oct.27, 2014), during which we can see the intense explosions. There are five X-class flares during this time, and NASA’s Solar Dynamics Observatory (SDO), which watches the sun constantly, captured these images of the event.
Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth’s atmosphere to physically affect humans on the ground, however — when intense enough — they can disturb the atmosphere in the layer where GPS and communications signals travel.
When referring to these intense solar eruptions, the letter part of the classification, ‘X’, means, ‘X-class’. This denotes the most intense flares, while the number, after the classification letter, provides more information about its strength. For example, an X2 is twice as intense as an X1, an X3 is three times as intense, and so forth.
Solar Images Credit: NASA’s Goddard Space Flight Center & SDO
http://SunSpotWatch.com ~ http://NW7US.us
73 de NW7US
Solar Cycle 25 Predictions
It has been notoriously hard to predict future solar cycles, but the science is improving all the time. Right now, the experts are predicting that solar cycle 25 will be very small indeed. Some think we are moving towards another Maunder Minimum when solar sunspots all but vanish for around 50 years. If so, most of us alive now will never experience “good” HF conditions ever again in our lifetimes. Experts can be wrong!
See http://wattsupwiththat.com/2012/01/25/first-estimate-of-solar-cycle-25-amplitudesmallest-in-over-300-years/ .
On a positive note, poor solar activity often means the lower frequency bands are better. With some luck, we may have a new international contiguous band at 60m in a few years’ time. This depends on WRC2015.
Regarding cycle 24, it looks like the peak was Feb 2014.
See http://www.solen.info/solar/ .
See http://www.solen.info/solar/ .
Looking at the data on this excellent page, it now looks pretty certain that we have started on the downwards part of the current cycle. This does NOT mean an end to decent HF conditions. For several years to come there will be good days and 15,12 and 10m will still support DX but far less easily than around the sunspot maximum years.
Even in the depths of the last minimum N-S DX was still there to be worked on QRP SSB, so expect some decent openings. This is really where regular WSPR operation will help, by seeing just how often 10m opens up. As I have said before, operating on the weaker parts of the solar cycle are, in many ways, more challenging and interesting. When 10m is wide open it becomes too easy.
Also, don’t forget Es (sporadic-E) which can produce some spectacular DX at the right time of the year – in the northern hemisphere this is usually May, Jun, July and August but Es can occur (more fleetingly) at other times times of the year. This is why regular WSPR operation will help.
Sunspots slowly falling?
Today’s sunspot count is 65 with “normal” 20-30MHz conditions. It looks to me as if the solar activity is now on the slide downwards. This does not mean an end to good conditions. This autumn 15, 12 and 10m should still be in very good shape and it will be a few years before we really see the changes.
There are all sorts of predictions about the next few cycles. The consensus is the next few cycles will be ones with low solar activity. It is still too soon to say if we are really entering another Maunder minimum. Don’t worry: this is a chance to explore HF in different times. There is unlikely to be good (any) E-W F-layer propagation on 12,10 and 6m but N-S propagation will be possible some of the time and openings on Es can be surprisingly distant in all directions at the optimum times of the year.
And there are always VHF, UHF, microwaves and nanowaves to explore!
See the coming months and years as a challenge. We may never see really good conditions again in our lifetimes but there will still be interesting propagation and DX to be worked and heard.