Slightly OT: Solar Activity - Coming to a Planet Near You 17-19 Nov : LUSENET : TimeBomb 2000 (Y2000) : One Thread


"Recent development The geomagnetic field was quiet on November 15. Solar wind speed ranged between 331 and 452 km/sec.

Solar flare activity was moderate. Solar flux was 205.6, the planetary A index was 6 (3-hour Kp indices: 2122 2210, Boulder K indices: 2122 2221). Region 8755 was quiet and stable. Region 8759 was mostly unchanged and quiet, the region still has M class flaring potential. Region 8760 decayed slowly and remains capable of minor M class flaring, the region will rotate off the visible disk on November 17. Region 8763 did not change significantly and could produce C and minor M flares. Region 8765 is still developing and has major flare potential. Region 8766 has a magnetic delta configuration and is developing slowly. Major flares from this region are possible. Region 8767 was quiet and stable, as was region 8768. New region 8769 rotated partly into view at the southeast limb, this region appears to have M class flaring potential.

Comment added at 04:53 UTC on November 16: The third M flare of the day is in progress. In contrast to the previous impulsive events this one is either a long duration or very long duration event. It has reached the class M1.2 level as I write this. The M3.8 flare from region 8766 earlier today was associated with a strong type II sweep and a slow coronal mass ejection. There is a chance it could impact the earth on November 19.

Comment added at 06:13 UTC: The long duration M flare mentioned above peaked at the M1.8 level at 05:07 UTC. The source of the flare was region 8759. Another M flare, the fourth this early today, is in progress and has reached the M1.2 level. It appears to be another long duration event.

Comment added at 08:32 UTC: Region 8759 was the source of the long duration event which started just after 06h UTC and peaked at 07:12 as an M2.3 event. The interplanetary magnetic field has strengthened considerably over the last hour and has swung moderately strongly to strongly southwards. This should result in a significant increase in geomagnetic activity, likely to the active to minor storm level. The source of the disturbance is uncertain, particularly since parts of ACE and SOHO data are unavailable because of precautions taken to protect the instruments on the spacecrafts from the Leonids. There is a possibility it could be the early start of the coronal stream which was expected to arrive on the 17th. Another possibility is the arrival of a CME.

Comment added at 09:24 UTC: The fifth M flare today is in progress and has reached the M1.0 level as I write this. The disturbance described above does appear to be CME related. Should the IMF swing fully southwards at its current level, major storming would be likely.

Comment added at 14:00 UTC: The geomagnetic field is currently at active to minor storm levels. The source of the disturbance is a CME, likely associated with the long duration M class event observed on November 12. The sixth M flare of the day is in progress and has reached the M1.1 level. November 16 is the day with the highest number of M flares in a single day during solar cycle 23.

Comment added at 17:23 UTC: ACE EPAM data shows a large increase in proton flux. The increase in energetic protons and electrons should arrive at earth very soon. A polar cap absorption event is possible. It is unknown which of the flares today was a proton flare, the ones originating in region 8759 are the most likely proton flare candidates.

Flares and CMEs 8 C flares and 1 M flare were recorded on November 15. Region 8763 was the source of an impulsive C8.9/1N flare at 17:14 UTC. Region 8765 produced a long duration M2.9/2N event peaking at 08:41 UTC, A C4.4 flare at 16:19 UTC and a C5.5/1F flare at 18:56 UTC. Region 8766 generated a C8.9 flare at 00:09 UTC and a C3.9 flare at 04:47 UTC. The region was the source of an impulsive M3.8 flare at 02:46 UTC on November 16. Another impulsive M3 flare peaked at 04:12 UTC today.

The background x-ray flux is at the class C1-C2 level.

Coronal holes A small coronal hole in the southern hemisphere was in a geoeffective position on November 14-15.

Forecast The geomagnetic field is expected to be quiet to unsettled on November 16. A coronal stream could influence the field on November 17-18 causing unsettled to minor storm conditions. A coronal mass ejection observed on November 14 could reach earth on November 17. If there is an impact, active to major storm would be likely. Low frequency (below 2 MHz) radio wave propagation along east-west paths over high and upper middle latitudes is generally poor and improving."

-- ng (, November 16, 1999


* Y2K is Real
* Y2K is a subset of the Millennium Problem.

-- Dan G (, November 16, 1999.

A possible auroral display coincident with the Leonids?

So long as no real damage was done, I think such a sight would be spectacular. A once-in-a-lifetime opportunity.

On rare occassions it is possible to get fairly dramatic auroral displays here in Iowa. Imagine a full-fledged meteor storm with an aurora as a back drop. Wow!

Yes, I know that a meteor storm is not a certainty with the Leonids this year, nor is an aurora certain, but one can dream....

Hoping for clear skies tomorrow night.

-- Arnie Rimmer (, November 16, 1999.


Please keep the information coming. I could not get into current EIT movies and pictures "forbidden". Last night I could look at all kinds of pictures. I don't understand the geomagnetic jargon, but I do understand the CME's / flares "can" have a serious effect on electricity (example:Quebec).

We had a lot of folks from Ind/ KY see a fireball crossing the sky tonight about 7:30. Seems Leniods are beginning.

All this is not y2k, however, our preps may come in handy. It getting cold and the new wood stove could be a true blessing.

Thank you,

-- Tess (, November 16, 1999.

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