Flare Sends A Gigaton Of Solar Detritus Toward Earth

Dr. Zowie writes: "This morning at about 10:00 UT, a major explosion occured on the Sun. The solar X-ray output went up by over 1,000 times. About a billion tons of material are speeding toward Earth at over a million miles per hour, and should hit sometime in the next couple of days. Low latitude aurorae and anomalies in radio communications and power service are likely consequences. You can see the event from the SOHO spacecraft's home page -- images and movies are here. In the movies, watch for the burst of radiation hitting SOHO about 13:00 UT -- that's a high energy proton storm caused by the flare itself. You can also see the earthly effects of a similar event from last year."

Comments

A Relative Number

[Anonymous Coward]

1 billion tons == 1,666 WTCs according to media reports estimating the weight of the WTC rubble at 600,000 tons.

More information at spaceweather.com

[B.D.Mills]

http://www.spaceweather.com has more information about this flare.

It is a class S3 flare, which is strong enough to expose people travelling in commercial jets at high altitude to radiation equivalent to 1 chest x-ray. On average, the Sun only has about a dozen storms this strong or stronger every solar cycle (11 years). In other words, it's a fairly big one. (reference: http://www.sec.noaa.gov/NOAAscales/#SolarRadiation Storms

Re:More information at spaceweather.com

[GeoNerd]

I don't want to seem overly picky here, but it's actually an X2.6 class flare - the resulting radiation storm is an S3 class event.

Practically Speaking

[maggard]

This will have repercussions on long-distance communications & electrical transmission.

Satellites will likely be affected, indeed some may either have their onboard electronics so disrupted they cease to function temporarily or permanently, in other cases the cameras they use for determining proper altitude may become so filled with transient glitches that they loose lock & station-keeping is compromised.

The Earth's ionosphere will expand and the Van Allen Radiation Belts will become heavily charged resulting in numerous radio transmission oddities ranging from increased static interference to long skips. Low Earth Orbit objects will experience increased drag and possibly require altitude increases. Inhabitants of the ISS should be protected by the magnetosphere though increased radiation counts will be experienced.

Long-distance electrical transmission lines will build up significant charge. The lines in Northern Quebec are especially vulnerable from to their high latitude and lack of grounding due to the ancient granitic nature of the Canadian Shield. However measures put in place since the "Great Northeast Blackout of 1965" should be sufficient to keep any failures local and not produce a domino effect.

To Geeks the result will be poor phone and dataline connections, possibly isolated electrical outages. TV signals will be poor as will most other forms of radio & microwave transmissions. Doubtless a few bits will flip from one state to another in the course of this but this will only be noticeable in very large samples.

The good news is we've just passed the first Solar Maximum of the Information Age without great issue and this bodes well for the future. Though storms like this current one are possible (with diminishing likelihood) for the next year or so it appears fears of widespread disruption due to Solar-Max of were unfounded and along with the GPS rollover, y2k, unix t_time going to 10 digits, various odd dates etc. we've managed to come through all remarkably unscathed.

Re:Practically Speaking

[Anonymous Coward]

calm down...this is a medium size solar flare in many terms and will not cause all the rampant problems that you are talking about. All the problems will occur to some extent, but not likely the sort of catastrophic events you are suggesting.

Most GEO spacecraft are going to have enough total dose lifetime that it will not affect them in terms of total dose and most mission profiles have a built in allotment for proton SEE from these types of solar flares...heck most of the components on GEO sats are radiation tolerant enough that protons do not cause upsets.

Most LEO spacecraft are relatively well shielded by the geomagnetic shielding of the planet and will not experience all that much of the energetic protons from the flares.

For ISS, the protons will be all shielded away, but there is likely some increased level of neutron production...apparently the walls of ISS were designed poorly to be quite good producers of neutrons during these types of events.

This really (so far) is not that big of a flare...take a look at July 14th, 2000 through July 19th, 2000 and if the on-orbit satellites fared alright through that one, this one is much less likely to cause problems.

Re:How does?

[John Miles]

HF radio propagation, and to a lesser extent VHF, depends on the relative height and RF permeability of the D, E, and F1 / F2 layers of the ionosphere. Both of these properties can change dramatically when the earth is bombarded with charged particles and high-energy photons from solar flares.

Normal ionospheric behavior is the reason why AM broadcast radio reception varies so much between daytime and nighttime hours. The lower (D) layer of the ionosphere is much thinner and higher at night when it's not being hammered by as much solar radiation. The AM broadcast band is near the very bottom of the high-frequency radio spectrum, and long-distance propagation of lower radio frequencies depends primarily on refraction by the D layer. So whenever the D layer rises, the "skip zone" around a given transmitter grows considerably. It's common to see nearby AM stations fade out at night, while even low-power transmissions become audible from thousands of miles away.

Solar flares have the same basic effect as the day/night cycle, but to a much larger degree. They usually just hose the entire HF spectrum, but sometimes the effect is very different. Under the right conditions, "ducts" and other layering effects can occur in the ionosphere, capable of propagating signals extreme distances with much less than normal loss. When you pick up a 5-watt ham radio station in Australia on your handheld shortwave radio in Texas, it's a safe bet that some unusual solar and/or geomagnetic activity is taking place.

Disclaimer: I'm a ham operator myself, but it's been a long time since I operated on any frequency below 10 GHz, so some or all of the details above may be shaky. :) I'm not sure about the exact mechanism of ionospheric excitation during a solar flare, for instance: it might be due primarily to heavy charged particles from the solar wind, or it might be due to high-energy photons knocking loose a few extra electrons here and there. Any physics types around who can clarify?

Peanuts

[Random Walk]

Although this is a fairly big event for a calm, middle-age star like Sun, it is peanuts compared to the events observed for younger and more active stars of similar mass (the brightest flare ever observed on a young solar-like star released 10000 times more energy than any flare on Sun). Which implies that Earth has experienced much more impressive flare events when the Sun was young.

Also the qouted gigaton of mass loss is not really that much. The Sun has 2x10^30 kg, and loses 5x10^9 kg per second (one from solar wind, four more from conversion of mass into the radiated energy). So one gigaton is just 200 seconds of normal mass loss.

Re:should hit sometime in the next couple of days?

[GeoNerd]

Yeah, what he said - also the particle stream will most likely be spread out over several days.

For example, look at the various graphs at the Space Environment Center and you can see that different things hit at different times. Right now were getting bombarded by the EM and high energy protons, while the matter from the coronal mass ejection will not get here for a few days. The radio blackouts and sensor dazzling are from the EM (X-rays mostly) and we're getting that NOW. But the matter from the coronal mass ejection is hurtling through space towards earth at some (relatively unknown) speed that depends on the speed at which it was ejected. THAT's the stuff that generates drag on satellites, causes the aurora, etc.

Also it's nearly impossible to calculate when you'll see the aurora, because that depends a lot on local conditions and a lot of other stuff that is completely unknown to science. Best bet is to keep an eye on the data from the POES satellite, which has some great plots showing likely auroral activity.

Mega-solar flares during solar maxima

[SysKoll]

It's interesting to note that these events (the July 13 2000 mega-flare and this one) happened during a solar maximum, i.e., the peak of a 11-year solar cycle.

There is a nice explanation with graphics here: http://www.windows.ucar.edu/cgi-bin/tour.cgi?link= /sun/activity/solar_cycle.html&sw=false&sn=872223& d=/sun/activity

Note that in spite of documented variations (e.g. the "Maunder Minimum" from 1650 to 1700, where cold climate coincided with very low solar spot counts), solar emissions are assumed to be constant in numerical climate simulation models. Which explains why these simulations are not exactly accurate.

-- SysKoll