look up tonight

[Dru]

A s t r o A l e r t

Sun-Earth Alert

 

Solar Terrestrial Dispatch

http://www.spacew.com

 

25 September 2001

 

1. POTENTIAL SIGNIFICANT AURORAL STORM WARNING.

2. WHITE LIGHT FLARE NOTIFICATION.

3. POTENTIAL SATELLITE ANOMALY WARNING.

4. COPY OF THE MIDDLE LATITUDE AURORAL ACTIVITY WARNING.

 

1. POTENTIAL SIGNIFICANT AURORAL STORM WARNING

 

A significant major class X2.6 solar flare was observed from a sunspot

complex identified by NOAA as sunspot complex number 9632. This solar flare

was associated with a strong Earthward directed coronal mass ejection. It is

expected to impact the Earth late in the UTC day of 25 September (anytime

near 18:00 UTC on 25 September or 2 pm EDT on 25 September). The impact of

this disturbance could produce periods of major auroral storm activity

("northern lights") that may become visible from many middle and low latitude

regions. In response to this potential activity, a Middle Latitude Auroral

Activity Warning has been issued together with a Low Latitude Auroral

Activity Watch for the days of 25 and 26 September. A copy of the middle

latitude warning announcement has been included below (see item 4).

 

2. Todays major X2.6 solar x-ray flare was reportedly observed in

white-light by Jure Zakrajsek of Slovenia. Additional white-light flares are

possible in this region. See: http://www.spacew.com/aurora/mdi_sunspots.jpg

 

3. A strong category S3 (rated from S1 to S5) solar radiation storm was

observed following the eruption of todays strong solar flare. Energetic

protons travelling at near relativistic speeds (near the speed of light) have

produced heavy ionospheric absorption of high frequency radio signals through

the polar ionospheric regions. Spacecraft in geosynchronous orbits may

experience increased incidences of SEU's (single event upsets), which are

caused when an energetic proton impacts a spacecraft and releases some of

its energy in semiconductors components on the spacecraft. SEU's can result

in "phantom commands" on spacecraft that may (or may not) require operator

intervention to correct. Strong proton events such as this can also

permanently degrade the performance of solar arrays on spacecraft. In

situations where spacecraft power levels are already low, energetic proton

events can force spacecraft operators to shut down instruments in order to

preserve power. Atmospheric drag on lower orbiting spacecraft is also

expected to increase following the arrival of the coronal mass ejection and

the ensuing geomagnetic storm. Spacecraft with cameras are already observing

the effects of the heightened proton activity in the form of increased cosmic

ray noise produced as protons impact spacecraft imaging sensors and trace

out streaks of light. These conditions can confuse star tracking systems used

to maintain accurate spacecraft orientations.

 

4.

 

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\

 

MIDDLE LATITUDE AURORAL ACTIVITY WARNING

 

ISSUED: 04:20 UTC, 25 SEPTEMBER 2001

 

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\

 

*** POTENTIAL FOR HIGH ACTIVITY EXISTS ***

VALID BEGINNING AT: 15:00 UTC 25 SEPTEMBER

VALID UNTIL: 19:00 UTC ON 28 SEPTEMBER

 

HIGH RISK PERIOD: 25 - 26 SEPTEMBER (UTC DAYS)

MODERATE RISK PERIOD: 25 - 28 SEPTEMBER

 

PREDICTED ACTIVITY INDICES: 30, 100, 40, 12 (25 - 28 SEPTEMBER)

 

POTENTIAL MAGNITUDE OF MIDDLE LATITUDE AURORAL ACTIVITY: HIGH

 

POTENTIAL DURATION OF THIS ACTIVITY: MAIN BELT = 24 TO 36 HOURS

MINOR BELT = 36 TO 48 HOURS

 

ESTIMATED OPTIMUM OBSERVING CONDITIONS: NEAR AND AFTER LOCAL MIDNIGHT

 

EXPECTED LUNAR INTERFERENCE: MODERATE, BECOMING NIL AFTER MOONSET NR MIDNIGHT

 

OVERALL OPPORTUNITY FOR OBSERVATIONS FROM MIDDLE LATITUDES: GOOD TO VERY GOOD

 

AURORAL ACTIVITY *MAY* BE OBSERVED APPROXIMATELY NORTH OF A LINE FROM...

 

CENTRAL/SOUTHERN CALIFORNIA TO ARIZONA TO NEW MEXICO TO TEXAS TO LOUISIANA

TO MISSISSIPPI TO ALABAMA TO GEORGIA AND POSSIBLY NORTHERN REGIONS OF

FLORIDA TO SOUTH CAROLINA.

 

ACTIVITY *MAY* ALSO BE OBSERVED APPROXIMATELY NORTH OF A LINE FROM...

 

EXTREME NORTHERN MOROCCO TO EXTREME NORTHERN ALGERIA TO NORTHERN TUNISIA

TO SOUTHERN ITALY TO GREECE TO EXTREME NORTHERN TURKEY TO GEORGIA TO

NORTHERN AZERBAIJAN TO SOUTHWESTERN KAZAKSTAN TO NORTHERN UZBEKISTAN TO

CENTRAL KAZAKSTAN TO EAST-CENTRAL KAZAKSTAN TO EXTREME NORTHERN MONGOLIA

TO EXTREME NORTHEASTERN CHINA TO CENTRAL SAKHALIN. THERE IS A SMALL

POSSIBILITY EXTREME NORTHERN JAPAN MAY WITNESS ACTIVITY.

 

IN AUSTRALIA, ACTIVITY *MAY* BE OBSERVED APPROXIMATELY *SOUTH* OF A LIHE

FROM NORTHERN NEW SOUTH WALES TO NORTHERN SOUTH AUSTRALIA TO CENTRAL

WESTERN AUSTRALIA.

 

ALL OF NEW ZEALAND HAS MAY OBSERVE ACTIVITY.

 

IN SOUTH AFRICA, THE EXTREME SOUTHERN TIP OF SOUTH AFRICA (NEAR CAPE TOWN

AND PORT ELIZABETH) *MAY* OBSERVE SOME ACTIVITY DURING THE HEIGHT OF THE

STORM, IF PREDICTIONS HOLD TRUE.

 

IN SOUTH AMERICA, SOUTHERN REGIONS OF CHILE AND ARGENTINA *MAY* SPOT

PERIODS OF ACTIVITY SOUTH OF A LINE OF ROUGHLY 50 DEGREES SOUTH LATITUDE.

THE FALKLAND ISLANDS MAY ALSO SPOT PERIODS OF ACTIVITY.

SYNOPSIS...

 

A strong solar flare and high velocity Earthward directed coronal mass

ejection were observed at 10:38 UTC (6:38 am EDT) on 24 September. The

coronal mass ejection is expected to impact the Earth near 18:00 UTC (2 pm

EDT) on 25 September, give or take several hours.

 

The arrival of this disturbance is expected to produce periods of major

to severe geomagnetic and auroral storm activity. This disturbance has the

potential to be one of the largest observed this solar cycle. Observations

well into the low latitude regions may be possible if predictions hold true.

 

Observations will be best after local midnight in the northern

hemisphere when the moon sets (or after about 3 am in Australia/New Zealand).

 

Forecasters suggest this disturbance has the potential to last as long

as perhaps 48 hours. As a result, most middle latitude regions of the world

should have at least one chance to observe activity. Whether this holds true

remains to be seen. Forecasts of storm durations are an inexact science.

 

This warning will remain in effect until 19:00 UTC on 28 September. It

will then be updated or allowed to expire.

 

PLEASE REPORT OBSERVATIONS OF AURORAL ACTIVITY TO:

http://solar.spacew.com/www/auroras.html

 

* OR *

 

Use the STD AURORA MONITOR Software to monitor conditions and

report sightings. It is available at:

http://www.spacew.com/aurora

 

For Real-Time News and Discussions with Experienced Aurora Enthusiasts:

http://www.spacew.com/irc

and join the #aurora channel (type /join #aurora)

WE HAVE A USEFUL DISCUSSION FORUM FOR AURORA ENTHUSIASTS AVAILABLE AT:

http://www.spacew.com/aurora/forum.html

** End of AstroAlert **

[hikerwa]

whoa dru, did you type all that?

hahaha

[hasbeen]

I'm definitely intrigued but my brain hurts enough from just being at work. I think I'll stick to reading the posts for the ropeup carpooling.

[Dru]

no I spammed it