From: LARRY KLAES (ljk4_at_msn.com)
Date: Wed Sep 14 2005 - 13:59:41 UTC
>From: Cary Oler <oler_at_solar.spacew.com>
>To: sun-earth_at_SkyandTelescope.com
>Subject: AstroAlert: New X-Class Solar Flares Extend Aurora Warning - 14
>Sept
>Date: Wed, 14 Sep 2005 12:09:42 +0000 (GMT)
>
>=================================================================
>This Is SKY & TELESCOPE's AstroAlert for Sun-Earth Interactions
>=================================================================
>
>A s t r o A l e r t
>
>14 September 2005
>
>Solar Terrestrial Dispatch
>www.spacew.com
>
>
>NEW X-CLASS SOLAR FLARES EXTEND AURORA WARNING
>
> Active sunspot region 10808 produced two new X-class solar x-ray
>flares
>during the last 24 hours. The most energetic of these produced an
>Earthward-directed coronal mass ejection that is expected to impact the
>Earth
>late this afternoon or evening. The impact is expected to reignite auroral
>storm conditions. If it arrives as-expected, the resulting intensification
>of
>auroral activity may place North America in a good position for observing
>the
>activity TONIGHT. The mid-latitude auroral activity warning has been
>extended
>through to 16 September. The next 3 to 4 days will be critical, as this is
>the time that Region 808 is "pointed" most directly toward the Earth.
>Coronal
>mass ejections follow essentially straight trajectories to the Earth,
>unlike
>the energetic protons that stream from strong solar events.
>
> For spacecraft and their sensitivity to energetic protons (the
>radiation
>environment), the most vulnerable period will be later this week when
>Region
>808 begins to approach the western solar limb. At that time, the Earth
>should
>be best "connected" to the magnetic field lines that emanate from Region
>808
>and gradually spiral outward toward the Earth in an archimedes-type spiral
>pattern. Energetic protons from major solar flares often reach the Earth
>fastest (and are associated with the highest energies and densities) when
>the
>Earth is magnetically connected to the flaring region. This is because
>enegetic protons are charged particles, and as such they prefer to follow
>the
>magnetic lines of force outward from the Sun.
>
> The updated warning statement is appended below.
>
>
>MIDDLE LATITUDE AURORAL ACTIVITY WARNING
>Updated: 11:45 UTC on 14 September 2005
>Solar Terrestrial Dispatch
>www.spacew.com
>
>
>VALID BEGINNING AT: EFFECTIVE IMMEDIATELY
>VALID UNTIL: 23:00 UTC (5 pm EDT) ON 16 SEPTEMBER
>
>HIGH RISK PERIOD: 14-15 SEPTEMBER (UTC DAYS)
>MODERATE RISK PERIOD: 14-16 SEPTEMBER
>
>PREDICTED ACTIVITY INDICES: 30, 50, 30, 20 (14 - 17 SEPTEMBER)
>
>POTENTIAL MAGNITUDE OF MIDDLE LATITUDE AURORAL ACTIVITY: MODERATE TO HIGH
>
>POTENTIAL DURATION OF THIS ACTIVITY: MAIN BELT = 24 HOURS
> MINOR BELT = 24-48 HOURS
>
>ESTIMATED OPTIMUM OBSERVING CONDITIONS: NEAR OR AFTER LOCAL MIDNIGHT
>
>EXPECTED LUNAR INTERFERENCE: MODERATE
>
>OVERALL OPPORTUNITY FOR OBSERVATIONS FROM MIDDLE LATITUDES: FAIR TO GOOD
>
>AURORAL ACTIVITY *MAY* BE OBSERVED APPROXIMATELY NORTH OF A LINE FROM...
> (THIS LINE IS VALID *ONLY* IF FAVORABLE STORM CONDITIONS OCCUR)
>
> OREGON TO SOUTHERN IDAHO AND NORTHERN UTAH TO WYOMING TO NEBRASKA TO
> NORTHERN MISSOURI TO SOUTHERN ILLINOIS TO KENTUCKY TO VIRGINIA.
>
>ACTIVITY *MAY* ALSO BE OBSERVED APPROXIMATELY NORTH OF A LINE FROM...
> (THIS LINE IS VALID *ONLY* IF FAVORABLE STORM CONDITIONS OCCUR)
>
> CENTRAL FRANCE TO NORTHERN SWITZERLAND TO SOUTHERN GERMANY TO THE CZECH
> REPUBLIC TO POLAND TO CENTRAL RUSSIA.
>
> NEW ZELAND AND SOUTHEASTERN AUSTRALIA SHOULD ALSO BE ABLE TO SPOT
>PERIODS
> OF ACTIVITY.
>
>SYNOPSIS...
>
> Active region 10808 continues to produce energetic solar flare
>activity.
>The latest X-class flare was associated with an Earthward-directed
>(full-halo) coronal mass ejection that is expected to arrive at the Earth
>near the end of the UTC day of 14 September (for North American observers,
>this translates to the late afternoon and/or evening hours of Wednesday, 14
>September). This disturbance will have the potential to produce periods of
>moderate to strong auroral storm conditions. Observations should
>be possible over wide-spread mid-latitude locations. We are expecting to
>see
>the passage of a magnetic cloud with this disturbance, which could further
>enhance the potential for storm conditions (preceded or succeded by quieter
>conditions as the IMF rotates away from a favorable orientation).
>
> This warning will remain valid through 23:00 UTC (5 pm EDT) on
>16 September, with a good chance that it will be extended beyond the 14th.
>It will be updated or allowed to expire at that time. For updated
>information, visit: http://www.spacew.com/aurora/forum.html. For real-time
>plots of current activity, visit: http://www.spacew.com/plots.html
>
> PLEASE REPORT VALID OBSERVATIONS OF AURORAL ACTIVITY TO:
> http://www.spacew.com/submitsighting.html
>
>
>** End of AstroAlert **
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