Last major update issued on July 5, 2006 at 04:50 UTC.
geomagnetic data - last month (updated daily)]
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[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update June 7, 2006)]
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The geomagnetic field was quiet to active on July 4. Solar wind speed ranged between 298 and 615 km/s (all day average 396 km/s - increasing 96 km/s over the previous day). A high speed stream from CH230 gradually increased its influence on the solar wind after 07h UTC.
Solar flux measured at 17h UTC on 2.8 GHz was 87.7 (values at 20 and 23h UTC
were influenced by long duration activity in AR 10898). The planetary A index
was 13 (STAR Ap - based on the mean of three hour interval ap
Three hour interval K indices: 11124334 (planetary), 11224334 (Boulder).
The background x-ray flux is at the class B1 level.
At midnight there were 2 spotted regions on the visible solar disk. The solar flare activity level was low. A total of 2 C class events was recorded during the day.
Region 10898 increased the areal coverage of the large penumbra. A large area surrounding this region appears to be somewhat unstable and a long duration event with an associated Earth directed CME is possible. Flare: C1.4 long duration event peaking at 20:29 UTC.
Spotted regions not numbered by NOAA/SEC:
[S667] This region rotated into view at the southeast limb late on July 4. Location at midnight: S05E81. Flare: C1.1 at 21:03 UTC.
July 2-4: No partly or fully Earth directed CMEs were detected in LASCO imagery.
Coronal hole history (since late October 2002)
Compare today's report to the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago
A recurrent trans equatorial coronal hole (CH230) was in an Earth facing position on July 1-3. A recurrent coronal hole (CH231) in the southern hemisphere will likely rotate into an Earth facing location on July 8-10.
Processed SOHO/EIT 284 image at 01:06 UTC on July 5. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be unsettled to minor storm on July 5 and quiet to active on July 6 due to a high speed stream from CH230. Mostly quiet is likely on July 7-8
|Coronal holes (1)||Coronal mass ejections (2)||M and X class flares (3)|
1) Effects from a coronal hole could reach Earth
within the next 5 days. When the high speed stream has arrived the color changes to green.
2) Effects from a CME are likely to be observed at Earth within 96 hours.
3) There is a possibility of either M or X class flares within the next 48 hours.
Green: 0-20% probability, Yellow: 20-60% probability, Red: 60-100% probability.
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is very poor. Propagation on long distance northeast-southwest paths is poor. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Radio Cristal del Uruguay had company from several other stations including Radio Vibración. On other frequencies most of the stations noted were from Brazil and Uruguay.
Compare to the previous day's image.
Data for all numbered solar regions according to the Solar Region Summary provided by NOAA/SEC. Comments are my own, as is the STAR spot count (spots observed at or inside a few hours before midnight) and data for regions not numbered by SEC or where SEC has observed no spots. SEC active region numbers in the table below and in the active region map above are the historic SEC/USAF numbers.
|Active region||Date numbered||SEC
|Location at midnight||Area||Classification||Comment|
|10898||2006.06.28||18||10||S07W14||0360||DKI||classification was CKO at midnight|
|Total spot count:||20||13|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2006.01||83.4||15.4||(20.7 predicted, -2.3)|
|2006.02||76.5||4.7||(18.2 predicted, -2.5)|
|2006.03||75.4||10.8||(16.4 predicted, -1.8)|
|2006.04||89.0||30.2||(15.7 predicted, -0.7)|
|2006.05||80.9||22.2||(14.9 predicted, -0.8)|
|2006.06||76.5||13.9||(12.7 predicted, -2.2)|
|2006.07||86.6 (1)||4.8 (2)||(11.3 predicted, -1.4)|
1) Running average based on the
daily 20:00 UTC observed solar flux
value at 2800 MHz.
2) Unofficial, accumulated value based on the Boulder (NOAA/SEC) sunspot number. The official international sunspot number is typically 30-50% lower.
This report has been prepared by Jan Alvestad. It is based partly on my own observations and analysis, and partly on data from some of these solar data sources. All time references are to the UTC day. Comments and suggestions are always welcome.