Die Suche ergab 119 Treffer

von janlameer
16. Okt 2010, 21:30
Forum: Polarlicht und Astronomie
Thema: M-class Flare 2010-10-16
Antworten: 5
Zugriffe: 575

interesting

Hi Alice The position of the CME on the solar surface looks good for a possible geo-effective CME. On average, in my experience, it takes about 55 hours for a CME to reach Earth, so that would mean Sat 16 Oct, 19 UT + 55 hrs = Mon 18 Oct 19UT + 7 hrs = Tue 09 Oct 02 hrs UT = early morning of Tuesday...
von janlameer
12. Sep 2010, 14:37
Forum: Leuchtende Nachtwolken (NLC)
Thema: how to calculate NLC distance
Antworten: 3
Zugriffe: 457

yes, thank you

Hi Andreas Thank you very much for digging this up. I've timelapse filmed NLC's in stereo 3D this summer, with a distance between camera's of approximately 6500 meters. We're working on the footage now. The high definition footage is very nice, and 3D red cyan anaglyph tests already showed that the ...
von janlameer
9. Sep 2010, 22:48
Forum: Leuchtende Nachtwolken (NLC)
Thema: how to calculate NLC distance
Antworten: 3
Zugriffe: 457

how to calculate NLC distance

Hi all ! I've asked this question a few years ago, got a good answer too, and lost the answer. So here it goes again : I'm looking for a good way to calculate the distance of NLC's from their measured height above the horizon. And I'm always insecure about how to include the near horizon refraction....
von janlameer
5. Aug 2010, 00:27
Forum: Polarlicht und Astronomie
Thema: Polarlichtsichtungen 04./05.08.2010
Antworten: 6
Zugriffe: 3081

Hi Michael You surely caught northern lights. If there were no clouds at your horizon, you probably would have seen a fairly bright green arc. The blue-violet nitrogen aurora is mixed with a bit of red oxygen aurora, at a height of approximately 200 - 500 km in the atmosphere. It is so-called sunlit...
von janlameer
3. Aug 2010, 22:33
Forum: Polarlicht und Astronomie
Thema: Schock-Impakt! 03.08.2010 - 16:56 UTC
Antworten: 19
Zugriffe: 4387

clouds in Netherlands

Hi all ! Here, 30 kms north of Amsterdam, we're 7/8 clouded out. But if you're on the road, with your camera, I advise you to stay alert. Geomagnetic conditions are favorable for some Northern Lights activity. Especially for the high Nitrogen sunlit blue - violet aurora that might show itself when D...
von janlameer
14. Jul 2010, 22:53
Forum: Polarlicht und Astronomie
Thema: Kp = 5 expected
Antworten: 0
Zugriffe: 381

Kp = 5 expected

Hi all ! Good old times again, Costello says Kp = 4.7 expected Density ACE 9 protons solar wind speed 400 km/s Bz = 16 nT (south) time = quater to one local MEZT time, night of Wednesday on Thursday (Wednesday 14 july 201022:45 UT) Here in the Netherlands we have a lot of clouds .. greetings, Jan La...
von janlameer
2. Jun 2010, 00:44
Forum: Leuchtende Nachtwolken (NLC)
Thema: Erste NLC-Sichtungen der Saison (Russland & Dänemark)
Antworten: 5
Zugriffe: 762

NLC 31 May confirmed from NL

Hi Stefan I can confirm a NLC sighting from the Netherlands, 30 km north of Amsterdam (near 53N, 5E) , Monday evening 31 May local MEZT around 23:30 - 00:15. Quite bright compared to the twilight, low over the WNW horizon, about 2 degrees over the free horizon, about 15-20 degrees wide, thick solid ...
von janlameer
24. Sep 2009, 10:21
Forum: Polarlicht und Astronomie
Thema: De Jager Grand Solar Minimum
Antworten: 0
Zugriffe: 388

De Jager Grand Solar Minimum

Hi all I found some quite interesting reading material on the site of prof. dr. C de Jager, well known solar scientist from the Netherlands (formerly at U. of Utrecht). He predicts that the sun is going abruptly from a grand maximum period into a grand minimum period that might last a century. Also ...
von janlameer
23. Okt 2008, 17:40
Forum: Meteore
Thema: copper debris falling ?
Antworten: 0
Zugriffe: 266

copper debris falling ?

Hi all ! Over the past two weeks I've seen two interesting fireballs, that were identical in nature but definitely from a different radiant. Location 30 km north of Amsterdam, Netherlands, aproximately 52 degrees North 5 degrees East. They both had the same brightness : about minus six magnitude, an...
von janlameer
23. Jan 2008, 13:53
Forum: Halos und atmosphärische Erscheinungen
Thema: Ansätze eines blauen Blitzes bei Sonnenaufgang, 25.12.07
Antworten: 11
Zugriffe: 1995

Kelvin Helmholtz disturbances

Hi All, we have a lot of snow now, so my acces to Internet is scarce, took my a while to post a reply. Thanks Reinhard for the name, I didn't know it was a Kelvin Helmholtz disturbance, I have been hoping to catch those cloudforms for a long time. Altocumulus intortus makes sense, and according to g...
von janlameer
5. Jan 2008, 18:19
Forum: Halos und atmosphärische Erscheinungen
Thema: Ansätze eines blauen Blitzes bei Sonnenaufgang, 25.12.07
Antworten: 11
Zugriffe: 1995

Hi Harald ! Very nice photographs, especially the fata morgana ! I did some sunrise pics in October 07 from the AstroQueyras observatory in the French Alps. The sun rose behind the Mont Viso, which is only 15 km away, and according to experts it is more easy to see the flash behind nearby mountains....
von janlameer
1. Apr 2007, 22:48
Forum: Polarlicht und Astronomie
Thema: Aktivitätshinweis 01./02.04.2007
Antworten: 1
Zugriffe: 692

Hi Lutz Yes, we have quite a lot of activity here in Porjus, all over the sky. The moon is pretty strong off course, spoiling most of it, but the sky is generally very clean with a bit of clouds. Pretty strong wind though and the snow has started to melt so it's almost impossible to walk, even with ...
von janlameer
27. Mär 2007, 18:05
Forum: Polarlicht und Astronomie
Thema: CH 262 wird aktiv (23.02.2007)
Antworten: 11
Zugriffe: 2942

Hi
Looks like the speed is suddenly going up, (18 UT, 27 March).
I wonder what will happen to-night, it is really clear here in Lappland.
JanL
von janlameer
24. Mär 2007, 17:29
Forum: Polarlicht und Astronomie
Thema: CH 262 wird aktiv (23.02.2007)
Antworten: 11
Zugriffe: 2942

Hi Lutz ! From what I'm seeing from the ACE data, it looks to me we're in the stream of CH261 and not CH 262 yet. The speed is going down again and there was a "perfect" change from Bz south to Bz north this afternoon. Looks to me there will be not so much activity to-night until the wind ...
von janlameer
24. Mär 2007, 04:45
Forum: Polarlicht und Astronomie
Thema: CH 262 wird aktiv (23.02.2007)
Antworten: 11
Zugriffe: 2942

Yes Florian, I can feel your tears because last night was almost unbelievable. I went up in the mountains and had a full night of aurora; a lot of very slow moving and not so bright arcs, good pulsating and three or four very intense substorms. The best was around 02:30 local time, it developed very...
von janlameer
22. Mär 2007, 21:31
Forum: Polarlicht und Astronomie
Thema: northern lights at less than 260 km/s
Antworten: 0
Zugriffe: 640

northern lights at less than 260 km/s

Hi all ! I just walked out and couldn't believe my eyes: there is a weak substorm going on here in Porjus, Lapland (69N, 20E) while the speed of the solar wind is lower than 260 km per second. Bz has been down to -4 nT a few times in the past hours but with the rule of thumb of the chance of a subst...
von janlameer
14. Mär 2007, 21:39
Forum: Polarlicht und Astronomie
Thema: Schwedische live Aurorawebcam (neu)
Antworten: 2
Zugriffe: 1295

Hi Marjorie Well, the auroracams here in Porjus aren't so new, they've been here allready for 2 years. And if you look closely on cam 1, you can see me sit there on the frozen lake with my time-lapse filmcamera. to the far left of the frame. We had a nice arc during twilight, a few small distant sub...
von janlameer
13. Mär 2007, 05:19
Forum: Polarlicht und Astronomie
Thema: SOHO back
Antworten: 0
Zugriffe: 661

SOHO back

Hi all ! New SOHO pics were just posted at http://www.lmsal.com/solarsoft/latest_events/ Seems our friend is up and running again ! Meanwhile here, we had two large auroral storms, dimly visible through the clouds; Norwegian magnetometers went from 150nT to 300nT and even briefly to the 600nT scale....
von janlameer
12. Mär 2007, 18:34
Forum: Polarlicht und Astronomie
Thema: Aktivitätshinweis CH 11.03.2007
Antworten: 7
Zugriffe: 2108

no activity yet

Well, my prediction didn't come out. Might be that the CH has shrunk again since last rotation. According to the TRACE pic on http://www.lmsal.com/solarsoft/latest_events/ it is quite small at the moment. But I'm not so sure wether this TRACE pic gives the best view on the CH, since SOHO still has a...
von janlameer
12. Mär 2007, 03:44
Forum: Polarlicht und Astronomie
Thema: Aktivitätshinweis CH 11.03.2007
Antworten: 7
Zugriffe: 2108

Well, Bz has been north allmost all night, but I did see a bit off far away aurora, in the direction north of Iceland, around 03 UT, with twilight starting. I'd say Bz will turn towards south somewhere to-day, I guess around noon or so. So I wouldn't be surprised if Bz will be near -15 nT after suns...