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Post by jcarels on Feb 13, 2011 15:56:48 GMT
What caused the spikes during SC14 or is that not know?
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Post by lsvalgaard on Feb 13, 2011 16:08:46 GMT
What caused the spikes during SC14 or is that not know? just spots coming and going, I presume. It has long been known that solar activity comes in 'episodes'. Precise reason unknown. |
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Post by af4ex on Feb 13, 2011 16:47:52 GMT
Bob and Doc I (or anyone else of course), I know things are going to get exciting today but I have a question sorta in a different direction. You may have noticed from previous posts (kinda infrequent, I know) that I'm a NAVAID tech. I had a most interesting event occur last Friday and wonder what you think about it. One of my VOR sites was being orbited by Flight Check just about the time that the Geo storm started on Friday. F/C took me off the air, that is they NOTAM'ed my VOR out of service because all of the radials were 3 degrees off. You don't want airplanes using your site when it's that far off. Normally, internal monitoring by the VOR itself will shut the facility down when it goes 1 deg off on ANY radial. 16 small antennas around the site's counterpoise constantly monitor the signnal. The site itself saw no problems, did NOT shut down, and when we checked it, everything was fine. Apparently the radial "bending" was only in space, not at the site. Three days later a F/C aircraft flew another orbit and all the radials were ... perfect. What could the geo storm have done to us? I had a similar event happen about 8 months ago at another site, in Southern Indiana, where only the radials east and south of the site "changed" by up to 5 degrees, then went back to normal a few days later. This time is was several commercial aircraft who reported the radial angles off, compared to GPS, and by the time Flight Check got there everything was back to normal. At issue is whether we ought to be taking sites off the air during a Geo storm. There's a lot of expense involved in having special aircraft come down to put us back on the air, plus the time that a NAVAID is down and unavailable. Some of us are already pushing these questions "upstream" but I was wondering what you guys think, since I HIGHLY value your knowledge of solar and geo mag things. Thanks. It would be tempting to blame these irregularities on geomagnetic storms. And there certainly was a tiny, but unambigous transient positive spike in the earth's magnetic field during the recent Kp=6 event. But that happened on the Asian side, and was registered on Japanese magnetometers. I looked for a signal on the North American chains but didn't see anything. solarcycle24com.proboards.com/index.cgi?action=display&board=general&thread=1306&page=50#64079I would think that any magnetic pulse strong enough to upset a VOR would also show up on the geological service magnetometers, which can measure disturbances down to a few nano teslas (nt). Has an internal malfunction been ruled out? Could it be related to the fact that the North Magnetic Pole is on the move, at a rate of 40km/yr towards Siberia? I think it's still in Canadian waters, but will be in Siberia in about 50 years if it keeps up its current heading and speed. Perhaps the internal dynamo process responsible for that is not entirely smooth. But I really know nothing about this area. (Dr. S. seems to know a lot about this aspect of geophysics). news.nationalgeographic.com/news/2009/12/091224-north-pole-magnetic-russia-earth-core.html |
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Post by af4ex on Feb 13, 2011 17:40:21 GMT
I said:
> It would be tempting to blame these irregularities on
> geomagnetic storms.
Oops, scratch that. I was thinking "storm", but that particular event was connected to the recent M1.9 _solar flare_, which did have a noticeable geomagnetic effect.
Of course a Kp=6 storm causes disturbances in the hundreds of nt's.
Strong enough to affect a VOR? I don't know. The Earth's field is much larger, on the order of 50,000 nt, so it would take quite a jolt to move the needle 3 degrees.
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Post by af4ex on Feb 13, 2011 17:52:14 GMT
M-CLASS FLARE (M7 or 8, a big one!) CURRENTLY IN PROGRESS! Looks like 1158:  |
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N9AAT
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Post by N9AAT on Feb 13, 2011 18:40:32 GMT
I'm not convinced myself, completely, that the events are related, but the correlation seemed like a possibility. To our knowledge this has never happened at this site. The fact that the site itself never saw a rotation of it's radials, yet an airplane orbiting at 20 miles out did, is somewhat telling. Even if a vehicle parks near a VOR site, like a farmer's combine during harvest, it will shut the site down for radial inaccuracies and we'll get a history of the event. In this case there was nothing, but the F/C bird said the entire course rotated 3 degrees.
Yes there's always the possibility of inaccuracies on the aircraft, but the did several sites that day and none of the others failed before or after our checks were done. Yes there's the possibility that the "back seater" did something wrong.
My hope is that our AVN people (flight check) will start looking into this to see if it happens again. They have all the histories, so I'm waiting to see what they come up with. If we get some other correlations, I'll post it here.
Again, please understand that this is nothing official. I'm just brainstorming with you guys because as both a ham and an FAA tech this interests me. Most of us are very 'particular' about what happens to our VOR sites (I personally have three), and besides that inquiring minds want to know. ;D
Looks like the sun "let a windy" about an hour ago. This could be an interesting day.
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N9AAT
Level 3 Rank
DON'T PANIC
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Post by N9AAT on Feb 13, 2011 18:50:57 GMT
Just saw NOAA call this an M6.6 flare with an emissions thingie. Stuff oughta be happening on 10/15/20-meters about now.
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Post by lsvalgaard on Feb 13, 2011 18:55:46 GMT
Just saw NOAA call this an M6.6 flare with an emissions thingie. Stuff oughta be happening on 10/15/20-meters about now. F10.7 just hit 126, but is contaminated by the flare. |
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Post by Bob k6tr on Feb 13, 2011 19:17:19 GMT
X-posted from WUWT: The polar fields have been changing of late. There are several points to make here: 1) because of the large pixel size [1/11 of the solar diameter] the polar fields measured at WSO will be seen to reverse about a year before they actually do. See paragraph [7] of www.leif.org/research/Cycle%2024%20Smallest%20100%20years.pdf2) the polar fields in the two polar caps are not strongly correlated, one can change a year or more before the other one. 3) the reversal is not a slow, regular progression, but proceeds in random jerks or ‘surges’ of opposite polarity moving towards the poles. On average there are about five such surges. obs.astro.ucla.edu/torsional.html4) the total polar flux is small, only a one thousandth of the sunspot flux [over the cycle]. 5) the past few months have seen a very powerful surge of positive polarity towards the north pole [but none so far towards the south]. Because the polar fields were already weak, this surge has completely cancelled the north polar fields, even to the point that the polar coronal hole that normally lives there has virtually disappeared. You can see that here: stereo-ssc.nascom.nasa.gov/beacon/beacon_secchi.shtml6) since we expect more surges in the year(s) to come it thus seems possible that the north polar fields might build to be stronger than they have been at this last minimum, thus presaging a large cycle 25. We don’t know this for sure, of course, but it seems very possible to me. This is somewhat unexpected, so, yes, these are interesting times Leif, with this said does this mean we should expect to see the trend in Bill Livingston's measurements reverse themselves some time in the future ? |
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Post by af4ex on Feb 13, 2011 19:41:13 GMT
NOAA has two M-Flares listed coinciding in time, peaking one minute apart. No attribution. 1158 is obviously one of the sources. What is the second source? #Event Begin Max End Obs Q Type Loc/Frq Particulars Reg# #------------------------------------------------------------------------------- 6310 1728 1737 1748 G13 5 XRA 1-8A M4.8 3.2E-02 6310 1728 1738 1747 G15 5 XRA 1-8A M6.6 4.0E-02 Could it be two separate explosions at 1158? Here's a close up of the main flare at AR1158 (from SDO AIA 335A video). But I think the frames are more than a minute apart. [edit: just noticed "Obs"column. GOES-13 and GOES-15. Two reports for same event?]  |
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Post by lsvalgaard on Feb 13, 2011 19:53:49 GMT
NOAA has two M-Flares listed coinciding in time, peaking one minute apart. No attribution. 1158 is obviously one of the sources. What is the second source? #Event Begin Max End Obs Q Type Loc/Frq Particulars Reg# #------------------------------------------------------------------------------- 6310 1728 1737 1748 G13 5 XRA 1-8A M4.8 3.2E-02 6310 1728 1738 1747 G15 5 XRA 1-8A M6.6 4.0E-02 Could it be two separate explosions at 1158? Here's a close up of the main flare at AR1158 (from SDO AIA 335A video). But I think the frames are more than a minute apart. [edit: just noticed "Obs"column. GOES-13 and GOES-15. Two reports for same event?] Two spacecraft... same event...different sensitivity... |
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Post by af4ex on Feb 14, 2011 0:24:35 GMT
Here's an interesting animation of the M-Flare, rendered in UV 1700A light, which shows the build up of magnetism (UV sunspots). The spots are relatively small before the flare and grow very quickly during the flare. I think UV1700A captures the overall structure and magnetic intensity of the active regions better than visible light, and shows the sunspots as well. But they're evidently filtered at a greater high-pass field strength than visible light (1500 Gauss). (That's why I refer to them as 'super-strength' UV-sunspots)  |
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Post by lsvalgaard on Feb 14, 2011 0:27:48 GMT
X-posted from WUWT: The polar fields have been changing of late. There are several points to make here: 1) because of the large pixel size [1/11 of the solar diameter] the polar fields measured at WSO will be seen to reverse about a year before they actually do. See paragraph [7] of www.leif.org/research/Cycle%2024%20Smallest%20100%20years.pdf2) the polar fields in the two polar caps are not strongly correlated, one can change a year or more before the other one. 3) the reversal is not a slow, regular progression, but proceeds in random jerks or ‘surges’ of opposite polarity moving towards the poles. On average there are about five such surges. obs.astro.ucla.edu/torsional.html4) the total polar flux is small, only a one thousandth of the sunspot flux [over the cycle]. 5) the past few months have seen a very powerful surge of positive polarity towards the north pole [but none so far towards the south]. Because the polar fields were already weak, this surge has completely cancelled the north polar fields, even to the point that the polar coronal hole that normally lives there has virtually disappeared. You can see that here: stereo-ssc.nascom.nasa.gov/beacon/beacon_secchi.shtml6) since we expect more surges in the year(s) to come it thus seems possible that the north polar fields might build to be stronger than they have been at this last minimum, thus presaging a large cycle 25. We don’t know this for sure, of course, but it seems very possible to me. This is somewhat unexpected, so, yes, these are interesting times Leif, with this said does this mean we should expect to see the trend in Bill Livingston's measurements reverse themselves some time in the future ? Yeah, probably in 50-70 years time  |
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Post by Bob k6tr on Feb 14, 2011 2:55:29 GMT
The Sunspot Count for today is 84. A new record for the Cycle. Group 1158 counted 31 spots.
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Post by Kevin VE3EN on Feb 14, 2011 3:25:12 GMT
NOAA has two M-Flares listed coinciding in time, peaking one minute apart. No attribution. 1158 is obviously one of the sources. What is the second source? #Event Begin Max End Obs Q Type Loc/Frq Particulars Reg# #------------------------------------------------------------------------------- 6310 1728 1737 1748 G13 5 XRA 1-8A M4.8 3.2E-02 6310 1728 1738 1747 G15 5 XRA 1-8A M6.6 4.0E-02 Could it be two separate explosions at 1158? Here's a close up of the main flare at AR1158 (from SDO AIA 335A video). But I think the frames are more than a minute apart. [edit: just noticed "Obs"column. GOES-13 and GOES-15. Two reports for same event?] Thanks for this image. Very nice. I added to main page. |
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