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Post by af4ex on Oct 16, 2010 17:25:15 GMT
> SDO's EVE has been showing the 304A reading > shooting up like a rocket for the last 4 hours Bob, Paul/n0nbh has a nice gadget that lets you plot 304A. Green -> EVE (SOHO) Blue -> SEM (SD) www.hamqsl.com/solar.htmlI don't really see a rapid shootup, but perhaps it's not visible at this scale. It looks like maybe the 304a levels are climbing out of a depression, back to some previous higher level. Why does the newer instrument (SEM) have a flatter response than EVE? I've been reading up on solar 304A and was surprised to learn (from Graham Bailey's site) that there are helium ions in the Earth's plasmasphere that also emit photons at 304A. gbailey.staff.shef.ac.uk/researchoverview.htmlNote that these plasmasphere researchers always seem to refer to it as "30.4 nm", (10 Angstrom = 1 nm). In fact it produces a bright 'airglow' which is readily seen by the IMAGE spacecraft: My questions for Bob or Leif: 1. Where does this plasmaspheric helium come from? the Sun? or perhaps just alpha particle artifacts from cosmic ray collisions? 2. Is this 30.4nm emission significant enough to play a role in the ionosphere similar to solar 30.4nm?
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Post by af4ex on Oct 16, 2010 19:14:22 GMT
The ACE Bz magnetometer just started diving South, so I suspect a connection is looming which will cause some magnetic fireworks.
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Post by Bob k6tr on Oct 16, 2010 19:34:19 GMT
Why does the newer instrument (SEM) have a flatter response than EVE? Equipment degradation. SOHO is an old bird and took quite a few CME Hits during the last cycle. Diodes can be rebiased to regain some performance but the recovered performance is small when compare to the cumulative loss of repeated hits. RE the Atmospheric 304A stuff I will have to dig into it but don't have the time right now.
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Post by Bob k6tr on Oct 16, 2010 19:35:55 GMT
The ACE Bz magnetometer just started diving South, so I suspect a connection is looming which will cause some magnetic fireworks. We had an M3 flare. I believe that is the largest of Cycle 24 thus far.
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Post by Kevin VE3EN on Oct 16, 2010 19:45:27 GMT
Largest Flare was..
M8.3 (2/12/2010)
Kevin
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Post by france on Oct 16, 2010 20:39:54 GMT
- thanks for the links af4ex the Professor Graham Balley researches are very interesting - Dr Svalgaard or Bob do you know something about this fact I read on french news that UV turned down 4 times more than expected during the last solar minimum but an enhancement of visible wavelengths is observed since 2003 ?
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Post by af4ex on Oct 16, 2010 21:13:37 GMT
> We had an M3 flare. I believe that is the largest of > Cycle 24 thus far.
Was the M3 flare related to the dip in Bz (which is now back to zero)?
I thought it took a while for solar wind disturbances to propagate.
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Post by ouxly40 on Oct 16, 2010 21:48:00 GMT
A new spot forming to the west of 1113?
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Post by lsvalgaard on Oct 16, 2010 22:51:22 GMT
> We had an M3 flare. I believe that is the largest of > Cycle 24 thus far. Was the M3 flare related to the dip in Bz (which is now back to zero)? I thought it took a while for solar wind disturbances to propagate. no, it takes 3-4 days for any changes to show up in Bz.
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Post by af4ex on Oct 17, 2010 0:34:55 GMT
>> Was the M3 flare related to the dip in Bz .... ? > no, it takes 3-4 days for any changes to show up in Bz. That's what I thought, the Bz disturbance was triggered by something else, which apparently kicked off early this morning. The USGS Pt. Barrow and Dead Horse magnetometers registered some anomalies on the order of 500nt around 1400Z, possibly related to this. geomag.usgs.gov/realtime/(I should add that those kinds of readings are not unusual for stations sitting so close to the auroral jets.) [Following report may be of interest to the Hams on this net] Now (2355Z) am hearing a West Coast station (w6iys) on 21015 Mhz chatting with a Japanese station (ja1dkt). I could hear both sides of the QSO here in Florida, but the JA station was barely readable (peak S2 or so, with fading). My antenna is a 40-meter dipole about 15ft above the ground. Haven't that kind of DX on 15 meters for a long time, though I don't listen very often. Maybe a sign that conditions are picking up a bit due to increased solar activity. (or at least wishful thinking). John/af4ex
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Post by farkstick on Oct 17, 2010 0:43:00 GMT
Canadian magnos Attachments:
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Post by af4ex on Oct 17, 2010 1:15:23 GMT
> Canadian magnos
Very interesting, thanks. First time I've seen these Canadian reports. I assume the plots are arranged so that the topmost report is furthest North. Eureka appears to be in Nunavut, sitting pretty close to the magnetic pole!
The readings are somewhat different from the USGS, with smaller peak-to-peak amplitudes, on the order of 200nt. Some early morning (UTC) stuff, which is not apparent on the USGS array and the midday stuff, which seems to coincide with the Alaskan sensors.
Is this data available real-time on the Web?
Thanks, John/af4ex
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Post by farkstick on Oct 17, 2010 1:23:22 GMT
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Post by af4ex on Oct 17, 2010 2:05:35 GMT
Thanks for the links. > Any idea what'd cause the bZ field deviation Perhaps something on the Sun a few days ago, maybe a coronal hole (CH425)? But solen downplays this possibility: www.solen.info/solar/Looking at the NOAA alerts this month, I see only 3 events. www.swpc.noaa.gov/alerts/alerts_timeline.html1. the CME on Oct 6, which caused the K-5 event 4 days later 2. An electron flux alert on Oct 13 3. Today's M3 flare So, I'm guessing, by elimination, it must have been from one of the sunspots. :-|
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Post by Bob k6tr on Oct 17, 2010 2:35:04 GMT
To expand on what Leif said. CMEs are composed of Three Principle Constituents. 1) Electromagnetic Radiation in the form of UV and X-Rays 2) Cosmic Rays in the form of high energy protons and alpha particles 3) Magnetic Storm Particles in the form low energy protons and electrons The speed of Category 1 is the speed of light (3 x 10 8m/s or 186,000 miles/sec) The sun is 93 million miles away. It takes 8.33 minutes for the X-Ray and UV energy to reach earth. This energy does not influence the earth's magnetic field but it does cause radio black-outs. The speed of Category 2 and 3 emissions does vary and that inturn affects their arrival time. Category 2 Particles can reach the earth in 15 minutes if they are motoring along but 2 hours is closer to typical. Category 3 Particles take anywhere from 1 to 4 days Remember CMEs are like snowflakes. No two are the same. Some are loaded with Energy, others are loaded with Charged Particles. And some have equal amounts of all 3 constituents. These are still relatively small flares. When we start having the bigger ones in a year or so it will be common to hear of Ground Level Proton events where ejected Protons stream down to earth at the poles. You will also hear about Polar Cap Absorption as X-Rays pump up the D- Layer of the Ionosphere You will also hear about Radio Sweeps or Radio Burst. Kevin has a good write-up about them in the Help Section www.solarcycle24.com/help.htmDo you want to hear the sun ? www.heliotown.com/Solar_Radio_Sweeps.htmlAnd even more. Here are some of the different types of sweeps. www.heliotown.com/Radio_Sun_Introduction.htmlThe effects of flares are easily recognizable. They are pretty much an impulse function so there is an initial shock to the ionosphere and not much else. Everything settles back down in a few hours. A geomagnetic storm from a Coronal Hole lasts at least 6 hours and can drag on for several days.
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