Posts Tagged ‘x-ray’
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
73 de NW7US
While many are talking about how Solar Cycle 24 is the weakest since the Maunder Minimum (the period starting in about 1645 and continuing to about 1715 when sunspots became exceedingly rare, as noted by solar observers of the time — see this Wiki entry), there are moments when activity on the Sun strongly increases, providing brief moments of excitement.
Here is a case in point, witnessed by the Solar Dynamics Observatory (SDO; see SDO Mission) on June 7, 2011, when the Sun unleashed a magnitude M2 (a medium-sized) solar flare with a spectacular coronal mass ejection (CME). The large cloud of particles mushroomed up and fell back down looking as if it covered an area almost half the solar surface.
SDO observed the flare’s peak at 1:41 AM ET. SDO recorded these images in extreme ultraviolet light that show a very large eruption of cool gas. It is somewhat unique because at many places in the eruption there seems to be even cooler material — at temperatures less than 80,000 K.
This video uses the full-resolution 4096 x 4096 pixel images at a one minute time cadence to provide the highest quality, finest detail version possible. The color is artificial, as the actual images are capturing Extreme Ultraviolet light.
It is interesting to compare the event in different wavelengths because they each see different temperatures of plasma.
Credit: NASA SDO / Goddard Space Flight Center
Video: http://g.nw7us.us/1aOjmgA – Massive Solar Eruption Close-up (2011-06-07 – NASA SDO)
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: http://g.nw7us.us/18a0QvI
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 http://SunSpotWatch.com
73 – de NW7US
Propagation Columnist, CQ Communications Magazine, Popular Communications Magazine