Intense Solar Flaring Continues

Active sunspot complex 10808 (also known as Region 808) continues to impress. It is now more fully in-view and is presenting itself as a very large sunspot complex that will (if its present size persists) be visible to the unaided (protected) eye over the next week to 10 days. Aside from the very large class X17 flare reported in the last Astroalert, it has managed to produce two additional major flares: a class X5 and a smaller class X1 within six hours of each other (the X5 occurred at 21:06 UTC [5:06 pm EDT] on 8 September, and the X1 occurred at 03:00 UTC on 9 September [11 pm EDT on 8 September]).

Region 10808 appears to be a magnetically complex monster, with at least one very probable strong delta magnetic configuration visible (opposite polarity umbrae located within a single penumbra). Such configurations are inherently less stable and are often associated with energetic solar flares. There is obvious strong magnetic shear visible in solar images of this region at various wavelengths that are undoubtably contributing to the energetic events. No significant change has been observed in the sunspot complex during the last 24 hours. Granted, it would be difficult to discern significant changes given its close proximity to the solar limb, but there is sufficient data available now to suggest that additional very strong solar flare activity will likely persist in the form of moderate to strong X-class events.

These recent events (the three X-class flares observed thus far) have elevated the population of energetic protons in the near-Earth space environment to levels that are now roughly 100 times more dense than normal background levels. Energetic protons are being redirected by the Earth's magnetic field toward the polar ionospheres, where they are bombarding and ionizing the polar ionosphere to levels sufficient to produce a phenomenon known as Polar Cap Absorption (or PCA). PCA is not harmful to human health, but can be dissasterous to high-frequency radio communications through the polar regions. Such radio signals are normally bounced off the lower side of the ionosphere and are returned back to the Earth, permitting long-distance radio communications to take place. But the energetic protons have ionized the lower ionospheric layers to levels capable of absorbing most radio signals that attempt to pass through that region. As a result, for large regions of the Earth where radio paths traverse the high and polar latitudes, a radio blackout is currently in effect.

Additional strong solar flare activity could significantly elevate proton populations over and above what is currently being observed, during the next two weeks. This could prove to be hazardous to the health of spacecraft in orbit around the Earth. Indeed, it is possible for vulnerable spacecraft to become crippled or even irrevocably lost. It is also possible that spacecraft reliant upon solar arrays for power may observe permanent degradations in performance. In other words, another effect of strong space radiation is to permanently reduce the efficiency of solar panels, causing a reduction in electrical output and therefore reduced lifetimes.

Space weather storms caused by the high velocity mass that is often ejected from such powerful solar events can also significantly reduce the lifetime of spacecraft through another method as well. During strong storms, the outer reaches of the Earth's atmosphere heats up and bloats outward into space. This bloating effect increases the atmospheric drag on spacecraft in near-Earth orbits and can cause their orbital parameters to change rapidly. Their lifetimes can therefore be reduced simply because the drag reduces their altitude, which can result in early re-entry of the spacecraft back to the Earth.

The intense radio bursts associated with these solar flares can produce interference with antennas that happen to be directed toward the Sun during the bursts. For example, if a strong solar flare occurs when the Sun is just rising and a cellular phone or other radio communications network (wireless internet, etc.) happens to be aligned in the direction of the rising Sun, the intense radio emissions from the Sun may interfere with the communications occurring in the network. This can result in poorer communications performance.

Thus, there are many ways in which Region 10808 may influence our activities here on the Earth during the next two weeks. Of course, this is all dependent upon whether it is capable of retaining its volatile nature. At the present time, this appears to be likely in the short-term. But such strong activity also often results in some stabilization in the sunspot complex, which could help curb future energetic activity.

Solar Terrestrial Dispatch: http://www.spacew.com

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