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Post by af4ex on Feb 4, 2011 19:13:41 GMT
Just noticed that Solar Wind Bz is dropping rapidly into negative territory. (Hence Auroral Alert is lit up). Also spotted a huge spike in the ACE telemetry plot. Is that an internally generated artifact, or something going on in the wind stream? Attachments:
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Post by af4ex on Feb 4, 2011 19:48:07 GMT
... more spikes in the ACE telemetry. Looks real (whatever it is). Attachments:
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Post by af4ex on Feb 4, 2011 20:10:34 GMT
The North American magnetometer chains (USGS and Canadian) started to pick up magnetic disturbances about 0240Z today. Expect more geomagnetic activity when that spike stuff out at the ACE observatory gets here in a few hours. Attachments:
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Post by lsvalgaard on Feb 4, 2011 22:24:38 GMT
... more spikes in the ACE telemetry. Looks real (whatever it is). The spikes in Phi are artifacts stemming from the fact that the angle wraps around from 360 degrees to 0 degrees. There are no spikes. Phi went from 0.0 degrees to 359.9 degrees, a very small change of 0.1 degree.... then back to 0.0 degrees |
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Post by af4ex on Feb 4, 2011 22:47:54 GMT
@leif
> Phi went from 0.0 degrees to 359.9 degrees, a
> very small change of 0.1 degree.... then back to 0.0 degrees
Ok, I see. Didn't know it was an angle. Perhaps they should just clip values below zero, or plot them as separate lines at the top, without trying to connect the points at the bottom.
In any case, looks like we'll see some geomagnetic effects from all of this negative Bz activity.
Thanks
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Post by lsvalgaard on Feb 4, 2011 23:38:39 GMT
@leif > Phi went from 0.0 degrees to 359.9 degrees, a > very small change of 0.1 degree.... then back to 0.0 degrees Ok, I see. Didn't know it was an angle. Perhaps they should just clip values below zero, or plot them as separate lines at the top, without trying to connect the points at the bottom. In any case, looks like we'll see some geomagnetic effects from all of this negative Bz activity. Thanks Phi is the angle the magnetic field makes to the direction of the Sun. It is 0 towards the sun, 90 and 270 along the Earth's orbit, and 180 away from the Sun. The heliospheric magnetic field at Earth has phi = 315 degrees for field towards the Sun, and 135 degrees for field away from the Sun along the Parker Spiral. |
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Post by af4ex on Feb 5, 2011 13:05:24 GMT
... and we did get hit by a big geomagnetic storm last night. Kp=6, which I believe is a record for SC24(?) The daily Ap index also went up to 21 yesterday. Usually hovering between 5-10. But it was just a brief episode, Kp went back to zero, but the solar winds are still very fast ~600 km/s. Bz is postive again, so 'protecting' us from further solar wind action, I guess. Attachments:
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Post by af4ex on Feb 5, 2011 13:13:04 GMT
The new sunspot AR1152 has produced seven flares since yesterday. All B-class. AR1150 seems to be fading away. The 1152 B3.1 flare at 0007Z was captured by the Nobeyama radioheliograph, which recorded an intensely bright 17Ghz microwave spot. It seemed to be much brighter than a B3 x-ray flare normally produces. Perhaps an indication that the flare propelled more charged particles to relativistic speeds (or to higher speeds) than usual. Attachments:
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bradk
Level 3 Rank
Posts: 199
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Post by bradk on Feb 5, 2011 13:19:04 GMT
Nice catch on the solar wind early yesterday John.
Looks like every spot on the earth facing side is fading...http://www.solen.info/solar/
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Post by af4ex on Feb 5, 2011 13:43:47 GMT
Nice catch on the solar wind early yesterday John. Looks like every spot on the earth facing side is fading...http://www.solen.info/solar/ ... making the outlook bleak for any spike in activity. In fact, the USAF 45-day forecasts for Ap and SFI look like straight-line extrapolations of the current activity => SFI will be only 82 on Mar 21! :-( Apparently they're not using the 'optimistic' models Hathaway et al. are using. www.swpc.noaa.gov/ftpdir/forecasts/45DF/020445DF.txt
Product: 45 Day AP Forecast 45DF.txt
:Issued: 2011 Feb 04 2100 UTC
# Prepared by the U.S. Air Force.
# Retransmitted by the Dept. of Commerce, NOAA, Space Weather Prediction Center
# Please send comments and suggestions to SWPC.Webmaster@noaa.gov
#
#
#-------------------------------------------------------------
45-DAY AP FORECAST
05Feb11 008 06Feb11 005 07Feb11 005 08Feb11 005 09Feb11 005
10Feb11 005 11Feb11 005 12Feb11 005 13Feb11 005 14Feb11 005
15Feb11 005 16Feb11 005 17Feb11 005 18Feb11 005 19Feb11 005
20Feb11 005 21Feb11 005 22Feb11 005 23Feb11 005 24Feb11 005
25Feb11 005 26Feb11 005 27Feb11 005 28Feb11 005 01Mar11 007
02Mar11 010 03Mar11 010 04Mar11 007 05Mar11 005 06Mar11 005
07Mar11 005 08Mar11 007 09Mar11 007 10Mar11 005 11Mar11 005
12Mar11 005 13Mar11 005 14Mar11 005 15Mar11 005 16Mar11 005
17Mar11 005 18Mar11 005 19Mar11 005 20Mar11 005 21Mar11 005
45-DAY F10.7 CM FLUX FORECAST
05Feb11 082 06Feb11 082 07Feb11 082 08Feb11 082 09Feb11 082
10Feb11 080 11Feb11 080 12Feb11 080 13Feb11 082 14Feb11 081
15Feb11 081 16Feb11 082 17Feb11 088 18Feb11 088 19Feb11 084
20Feb11 083 21Feb11 081 22Feb11 080 23Feb11 081 24Feb11 081
25Feb11 081 26Feb11 083 27Feb11 081 28Feb11 082 01Mar11 082
02Mar11 082 03Mar11 084 04Mar11 084 05Mar11 084 06Mar11 084
07Mar11 084 08Mar11 086 09Mar11 088 10Mar11 088 11Mar11 088
12Mar11 088 13Mar11 088 14Mar11 088 15Mar11 088 16Mar11 088
17Mar11 088 18Mar11 088 19Mar11 088 20Mar11 084 21Mar11 082
FORECASTER: Weaver / Westlund
99999
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Post by lsvalgaard on Feb 5, 2011 14:52:16 GMT
Nice catch on the solar wind early yesterday John. Looks like every spot on the earth facing side is fading...http://www.solen.info/solar/ ... making the outlook bleak for any spike in activity. In fact, the USAF 45-day forecasts for Ap and SFI look like straight-line extrapolations of the current activity => SFI will be only 82 on Mar 21! :-( Apparently they're not using the 'optimistic' models Hathaway et al. are using. www.swpc.noaa.gov/ftpdir/forecasts/45DF/020445DF.txtBeware of the difference between the observed [what the ionosphere sees] and adjusted [what the Sun puts out] solar flux. |
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bradk
Level 3 Rank
Posts: 199
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Post by bradk on Feb 5, 2011 15:05:19 GMT
Dr Svalgaard-
How are the observed and adjusted values related? Does the SIM data on wavelength changes have any meaningful effect on observed?
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Post by af4ex on Feb 5, 2011 15:07:00 GMT
@leif
> Beware of the difference between the observed [what the
> ionosphere sees] and adjusted [what the Sun puts out]
> solar flux.
I thought that amounted to normalization to 1 A.U. Is there more to it? Which measurement does the USAF report?
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Post by lsvalgaard on Feb 5, 2011 15:15:32 GMT
@leif > Beware of the difference between the observed [what the > ionosphere sees] and adjusted [what the Sun puts out] > solar flux. I thought that amounted to normalization to 1 A.U. Is there more to it? Which measurement does the USAF report? It is the normalization. USAF forecasts the observed rate as that is what matters for them. You get both numbers here: ftp.geolab.nrcan.gc.ca/data/solar_flux/daily_flux_values/fluxtable.txtP.S. the URSI numbers is the REAL flux [10% smaller than the observed flux, but nobody cares about that one]. |
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Post by af4ex on Feb 5, 2011 15:49:38 GMT
@leif
> USAF forecasts the observed rate as that is what matters
> for them.
Ouch. That means the SFI of "82" that they're forecasting for 21 Mar is really "79.9".
"It's worse than we thought!" :-\
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