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A s t r o A l e r t
Sun-Earth Alert
Solar Terrestrial Dispatch
http://www.spacew.com
Valid: 08 and 09 June 2000
* Middle Latitude Auroral Activity WARNING *
* Low Latitude Auroral Activity WATCH *
A potentially significant solar coronal mass ejection is
currently
in-transit toward the Earth. Impact of this disturbance is expected
during
the mid to late UTC hours of 08 June. Its arrival is expected to
herald an
intensification of auroral activity. Minor to major auroral storming
may be
observed over possible widespread middle (and possibly some dark-sky
low)
latitude locations on the evenings of 08 and/or 09 June. Heaviest
emphasis is
currently placed on 09 June, although this will depend to a large
extent on
precisely _when_ the disturbance impacts.
There is no question that this disturbance will impact the Earth.
The
question is how intense the resulting auroral activity might become.
This is
a question which ultimately will not be answerable until after the
disturbance reaches the vicinity of the Earth where spacecraft can
probe the
interior of the disturbance upstream of the Earth. From that
information, we
will be able to determine much more accurately how the disturbance
should
progress.
We have appended below the official release of the middle
latitude
auroral activity warning, which includes roughly estimated boundaries
for
observing activity. However, keep in mind that these are estimates
only based
on anticipated peak auroral storm levels. Whether your local region
experiences peak storm conditions depends in a large measure on
factors
beyond anyones control (timing of arrival, dimensions of the
disturbance
impacting the Earth, characteristics of the solar wind within the
disturbance, and much more).
This is a potentially significant disturbance and should be
treated
seriously by those who would like to observe auroral activity. Plan
your most
intensive observing sessions after the moon sets and prior to local
twilight
conditions (but don't necessarily limit your observations to those
times or
you may miss the most intense phases of activity). For this event, the
moon
will set between 2 and 3 am local time, providing optimally dark skies
in the
hour or two prior to moonset and for the next few hours prior to
sunrise.
Avoid city lights. Get away to a rural location where city or
other
lights minimally pollute the northern horizon of the sky (or southern
horizon
if you live in the southern hemisphere).
Take along a camera with a tripod. During your observing session,
take a
few extended duration exposures of the horizon, even if you don't see
anything with your eyes. You may be surprised what shows up on film.
Binoculars or a small telescope may help, if for no other reason
than to
help pass the time while waiting for auroral storming to produce
bursts of
visible activity.
Before you go out, check the Internet for possible signs of
activity.
Ground-based reports from other individuals around the world are
available
at: http://www.spacew.com/www/auroras.html. Reports of auroral
activity there
can provide you with information on the latitudinal extent of auroral
activity visibility. Current auroral activity information can also be
obtained at: http://www.spacew.com/www/aurora.html. Other sites of
interest
include the Canadian Space Agency's near-realtime aurora plot at:
http://www.dan.sp-agency.ca/www/globe/rtoval.htm, their photometric
plots at:
http://www.sp-agency.ca/www_forms/rt_mpa.htm, and their all-sky imager
at:
http://www.sp-agency.ca/www_forms/rt_asi.htm.
Other useful sites include the Geophysical Institute at the
University
of Fairbanks Alaska (www.gi.alaska.edu) and Mark Hauns automatic
aurora
monitors (http://angwin.csl.uiuc.edu/~haunma/aurora). There is also
handy
software available that will provide you with near-realtime
notification of
auroral activity, based on current solar wind conditions (see:
http://www.spacew.com/www/geolert.html or for SEROIUS observers:
http://www.spacew.com/swarm).
PLEASE report any sightings of activity you make (whether
immediately or
several days after the event) to:
http://www.spacew.com/www/subaurora.html
so we can maintain a permanent archive of world-wide ground-based
sightings
for future study and reference.
The official middle latitude auroral activity warning, issued at
07:05 UTC on 07 June is included below:
VALID BEGINNING AT: 12:00 UTC 08 JUNE
VALID UNTIL: 19:00 UTC ON 10 JUNE
HIGH RISK PERIOD: 08 - 09 JUNE (UTC DAYS)
MODERATE RISK PERIOD: 08 - 10 JUNE
PREDICTED ACTIVITY INDICES: 12, 35, 60, 30 (07 JUNE - 10 JUNE)
POTENTIAL MAGNITUDE OF MIDDLE LATITUDE AURORAL ACTIVITY: MODERATE TO
HIGH
POTENTIAL DURATION OF THIS ACTIVITY: MAIN BELT = 12 TO 18 HOURS
MINOR BELT = 24 TO 36 HOURS
ESTIMATED OPTIMUM OBSERVING CONDITIONS: AFTER APPROX. 2 AM LOCAL TIME
EXPECTED LUNAR INTERFERENCE: LOW-MODERATE, BECOMING NIL AFTER 2-3 AM
LOCAL
OVERALL OPPORTUNITY FOR OBSERVATIONS FROM MIDDLE LATITUDES: GOOD
AURORAL ACTIVITY *MAY* BE OBSERVED APPROXIMATELY NORTH OF A LINE
FROM...
NORTHERN CALIFORNIA TO NORTHERN NEVADA TO UTAH TO COLORADO TO
NORTHERN
KANSAS TO MISSOURI TO KENTUCKY TO VIRGINIA.
ACTIVITY *MAY* ALSO BE OBSERVED APPROXIMATELY NORTH OF A LINE FROM...
NORTHERN FRANCE AND POSSIBLY EXTREME NORTHERN REGIONS OF SPAIN TO
SOUTHERN GERMANY TO SOUTHERN POLAND TO SOUTHERN UKRAINE TO
CENTRAL
RUSSIA. SOUTHERN REGIONS OF AUSTRALIA AND MOST OF NEW ZEALAND MAY
ALSO
SPOT POTENTIALLY SIGNIFICANT ACTIVITY.
RECEIVE REAL-TIME AURORAL ACTIVITY WATCHES AND WARNINGS BASED ON
REAL-TIME
SOLAR WIND CONDITIONS USING THE SOFTWARE AT:
http://solar.spacew.com/swarm
SYNOPSIS...
A significant solar coronal mass ejection associated with a
powerful
X-class solar flare was observed today leaving the Sun on a trajectory
toward
the Earth. This disturbance has the potential to produce periods of
significant and intense auroral activity over widespread middle and
possibly
some low latitude regions. The conservative forecast calls generally
for
minor auroral storming with occasional major substorm intervals
capable of
being observed throughout the upper-middle latitude regions. However,
there
is a fair to good chance that activity will reach occasional stronger
levels
capable of being observed across much wider central middle and
upper-low
latitude regions during the height of the activity, particularly if
observations are made just after the moon sets (between 2 and 3 am
local
time) and prior to the start of morning twilight conditions.
This is a potentially significant auroral storm prediction.
Observers
wishing to observe activity should take this event seriously. The peak
of the
storm activity is expected to occur on 09 June, although significant
levels
of activity may occur somewhat earlier if the disturbance is
travelling
faster than anticipated. Although the true intensity of activity won't
be
known until after the disturbance arrives (no one knows the intensity
or
configuration of the magnetic fields present in the disturbance until
after
spacecraft sample the solar wind within the disturbance - and that
won't
happen until the disturbance arrives).
Observers may want to plan excursions to dark-sky sites on the
evenings
of June 08 and June 09. If no activity is observed on the first night,
perhaps something will be seen the following night. Long-exposure
photographs
of the horizon may also reveal activity invisible to the eye after the
disturbance arrives. Serious observers may want to spend the $25 USD
to
purchase Ge+lert, which provides early notification of potential
levels of
auroral activity as well as current lists of ground-based sightings.
The
software is available at: http://www.spacew.com/www/geolert.html. FAX
orders
(MC/VISA) to: +1-403-756-3008 or: +1-403-756-2380 for rapid Internet
delivery.
There is a fairly high probability for additional powerful solar
flares
from the active sunspot group currently on the Sun over the next
several
days. The occurrence of additional major levels of solar activity
could
herald additional coronal mass ejections capable of impacting the
Earth.
This warning will remain active until 19:00 UTC on 10 June. It
will then
either be updated or allowed to expire.
PLEASE REPORT OBSERVATIONS OF AURORAL ACTIVITY TO:
http://solar.spacew.com/www/auroras.html
ESTIMATED AURORAL VISIBILITY FROM THE GROUND, AS WELL AS
SPACECRAFT
AURORAL IMAGERY AND STATISTICAL PLOTS OF ANTICIPATED ACTIVITY CAN
BE
FOUND AT:
http://www.spacew.com/www/aurora.html
** End of AstroAlert **