Aurora watch next 72 hours

[beskeptical]

What's Up in Space -- 18 Mar 2003
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SOLAR EXPLOSIONS: Magnetic fields above sunspot 314 have erupted twice: at 1905 UT on March 17th and at 1205 UT on March 18th. Both explosions sparked X1-class solar flares and hurled coronal mass ejections (CMEs) into space: #1, #2. Neither CME was squarely Earth-directed. Nevertheless, the expanding clouds could deliver glancing blows to our planet's magnetic field on March 19th and 20th. This adds to the already good chance of high-latitude auroras during the next 48 hours.

Were in a solar wind stream ~800kms^-1. That's high. Normal is in the 100-300, 400-500 is usual high speed and >800 is pretty unusual.

I know that much but maybe someone can tell me why the corona blocks the solar wind and why we get high winds from 'coronal holes'? Or does the wind cause the hole? Thanks.

[me04]

what would this do exactly to the earth?

[beskeptical]

On 2003-03-18 21:42, me04 wrote:
what would this do exactly to the earth?


Nothing, they are just beautiful to watch.

If we had a large CME directly aimed at Earth it can damage satelites and power grids but this one won't do that.

[Gramma loreto]

Thanks for the heads up. If our weather cooperates, I'll keep my eye out...and maybe my camera if I can swing the time.

[g99]

This might seem like a obvious question, but how far south (North Hemisphere) will you be able to see them? I know that i will never see them, i am way to far south. Just wondering.

[beskeptical]

On 2003-03-19 02:20, g99 wrote:
This might seem like a obvious question, but how far south (North Hemisphere) will you be able to see them? I know that i will never see them, i am way to far south. Just wondering.


I know they can be seen occasionally as far south as Arizona. The problem is predicting them is a fuzzy science, and, when you are as far south as I am in Seattle they show for a few minutes up to 20 minutes or so and then fade out again. So you have to be patient and watch for them often. I have seen them 4 times from my window. They can occur 10 or more times a year here but we have clouds and city lights that interfere. Right now the full Moon is also not good for viewing.

I'm waiting for the sudden impulse to show on the SEC site.

http://www.sec.noaa.gov/alerts/warnings_timeline.html

That will mean the CME reached a satelite about an hour away. Unfortunately there is no guarantee the CME will arrive at all. And, if it does arrive, it doesn't always trigger an aurora I can see at this latitude.

But I'm one of those folks who will stare out the window for hours waiting to see green ribbons in the sky. Fortunately my living room is conducive to that. My house is on a hill and we have 2 big picture windows. One looks out into the forest, (backyard is a 100 acre park, /phpBB/images/smiles/icon_biggrin.gif ), and the other looks out to the sky with just a little bit of the neighbors roof line.

So being the strange person that I am, I turn the TV on with the picture darkened and watch out the window.

_________________
Evolution is just a theory. Better fasten your seatbelt, so is gravity.
Beskeptigal.

<font size=-1>[ This Message was edited by: beskeptical on 2003-03-19 03:15 ]</font>

[gethen]

We generally can see the aurora here when they're active, at about 44 degrees.

[Hale_Bopp]

Actually, on very rare occasions, Aurora can be seen in Florida. I remember reading about one in late 1990 or early 1991 that was seen from north Florida.

I remember it because I was on the island of St. Croix at the time, too far south even for that one and getting envious of missing these great displays!

Rob

[SiriMurthy]

Can it be seen from Kansas City this time? I have never witnessed an aurora so far.

[DoctorDon]

SOLAR EXPLOSIONS: Magnetic fields above sunspot 314 have erupted twice: at 1905 UT on March 17th and at 1205 UT on March 18th.


This one really messed me up. I saw a very interesting X-ray flare, coming from a direction completely opposite to the sun, and thought I had discovered some new flaring system, like an unusual X-ray binary with a black hole or something. No, it was just this solar flare, reflecting off of the Moon!

Grrr...

Don

[g99]

On 2003-03-19 12:56, Hale_Bopp wrote:
Actually, on very rare occasions, Aurora can be seen in Florida. I remember reading about one in late 1990 or early 1991 that was seen from north Florida.

I remember it because I was on the island of St. Croix at the time, too far south even for that one and getting envious of missing these great displays!

Rob


Really? I am in North central florida!
When would be the best time to see it.

But the only thing i have seen are squirels, PX, and gators. /phpBB/images/smiles/icon_smile.gif

p.S. funnyest thing is: I used to live in Toronto, CA. But i really don't remeber ever seeing the Aurorae. Maybe the lights of the nearby city were to bright, or i went inside to early. But i was young when i moved. 11 years old. I would of loved to of seen one now that i think about it. /phpBB/images/smiles/icon_frown.gif

[carolyn]

Doctor Don

Is this why the moon has looked SO bright over the last couple of days then?

Wondered about that!

<a name="JD2452719.SS"> page JD2452719.SS aka SS {long ago}


<A NAME="PGU3"> SUNs SPOT (ver 1 2 3) </A>






<UL>


<LI><A HREF="http://www.solar.ifa.hawaii.edu/ARMaps/armaps.html">
1: get spot number & location from hawaii </A>
<LI><A HREF="gopher://solar.sec.noaa.gov/11/plots/xray">
2: get event time from Geos 8-9 xray </A>
<LI><A HREF="http://www.nso.noao.edu/synoptic/synoptic.html">
3: check magnetic image from noao </A>


[/list]

<font size=-1>[ This Message was edited by: HUb' on 2003-03-20 06:11 ]</font>

[David Hall]

On 2003-03-20 01:47, carolyn wrote:
Doctor Don

Is this why the moon has looked SO bright over the last couple of days then?

Wondered about that!


I wouldn't think so. X-rays are of course outside the visible spectrum. They wouldn't affect the apparent brightness of the moon.

I think what you're seeing is simply the full moon. At fullness, the moon appears up to 50% brighter than at other times because of two effects. The first is simply the zero-phase effect. Any shadows cast by objects are blocked by the objects themselves when you look at them from the direction of the light source, so you're getting reflection from almost 100% of the surface, unlike at other angles where shadows reduce the percentage of reflective area.

The second effect is called the heiligenschein. The lunar soil is saturated with small glass beads thrown out from meteor impacts. These beads tend to reflect light back directly along the path that it came from. So at fullness, you get added reflectivity from the soil itself. The same effect (http://www.weather-photography.com/Photos/gallery.php?cat=optics&subcat=heiligenschein) can be seen when water droplets cover grass fields, for example.

Actually, there's a third effect. The full moon (http://www.theman.themoon.co.uk/Moon.htm) in March was also near perigee, or the closest point in it's orbit to the Earth. So it also appeared a little larger than average.

Uh, sorry for over-answering here. I just got carried away. /phpBB/images/smiles/icon_smile.gif

[RafaelAustin]

On 2003-03-19 13:01, SiriMurthy wrote:
Can it be seen from Kansas City this time? I have never witnessed an aurora so far.

Here's a neat map (http://www.sec.noaa.gov/pmap/) of area covered by aurora.

The plots on this page show the current extent and position of the auroral oval at each pole, extrapolated from measurements taken during the most recent polar pass of the NOAA POES satellite. "Center time" is the calculated time halfway through the satellite's pass over the pole.

[SiriMurthy]

Here's a neat map (http://www.sec.noaa.gov/pmap/) of area covered by aurora.


Thanks, Rafael. Looks like the Kansas City area is right at the edge of this aurora.

Unfortunately, though, we have overcast skies for today and most part of tomorrow.

I hope to witness an aurora some day.

[beskeptical]

AURORA UPDATE: A coronal mass ejection swept past Earth at 0455 UT on March 20th. Our planet was already inside a gusty solar wind stream when the CME arrived,and the impact did little to increase geomagnetic activity. Another CME could be on the way--the second of two ejected from sunspot 314 in recent days. Sky watchers should remain alert for auroras after local nightfall on March 20th. The best viewing sites would be at high-latitudes: e.g., New Zealand, southern Australia, Canada, northern Europe, Alaska and northern continental US states like Michigan and Wisconsin. NOAA forecasters estimate a 5% chance of severe geomagnetic activity at middle latitudes, too.

Curses, foiled again. It rained all night. But if one CME hit, the other originated from the same place, (rotated one day), and the sky is clearing so I'll be looking out the window again tonight.

I don't want to confuse anyone here. Folks south of lat. 50, (or north of the southern 50) don't see aurorae very often. Between 40 and 50 you can see it more often if you have very dark skies and lots of clear nights.

The site above Rafael Austin posted is one I go to all the time. But you cannot see the aurora as far south, (or north) as the light blue colored area. It takes an activity level 10 for the aurora to show up in Seattle. At that level the red and yellow on that map reach Seattle.

Go to the site and click on 'aurora viewing'. That will give you an idea what activity level is needed for your location.

When there's a CME headed for Earth that is big enough to trigger a severe storm, that would be worth staring out the window, (or going outside if it's warm), for hours if you live south of lat. 40. Otherwise you have to be even crazier than me to be looking for auroras. We are unlikely to get a severe storm this time.

[beskeptical]

On 2003-03-19 15:26, DoctorDon wrote:

SOLAR EXPLOSIONS: Magnetic fields above sunspot 314 have erupted twice: at 1905 UT on March 17th and at 1205 UT on March 18th.


This one really messed me up. I saw a very interesting X-ray flare, coming from a direction completely opposite to the sun, and thought I had discovered some new flaring system, like an unusual X-ray binary with a black hole or something. No, it was just this solar flare, reflecting off of the Moon!

Grrr...

Don


OK Explain this to me. I don't get it. You were observing the Moon or in the direction of the Moon in X-ray wavelengths instead of visible light wavelengths and the solar X-ray event reflected off of things the way visible light does? Wow, I didn't know that.

_________________
Evolution is just a theory. Better fasten your seatbelt, so is gravity.
Beskeptigal.

<font size=-1>[ This Message was edited by: beskeptical on 2003-03-20 18:00 ]</font>

[beskeptical]

Still cloudy after all these days, yaaa, still cloudy, still cloudy....

Par for the course.