Last major update issued on August 6, 2010 at 05:15 UTC.
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The geomagnetic field was quiet to active on August 5. Solar wind speed ranged between 447 and 504 km/s.
Solar flux measured at 20h UTC on 2.8 GHz was 82.7. The planetary A index was 10 (STAR Ap - based on the mean of three hour interval ap indices: 9.6). Three hour interval K indices: 43011222 (planetary), 44111212 (Boulder).
The background x-ray flux is at the class B1 level.
At midnight UTC the visible solar disk had 4 spotted regions.
Region 11092 lost the small spots from the previous day. However, two
new small spots emerged, one of them distant from the leader spot. The other
small spot is a little problematic. Although it appears to be part of region
11092 and is located due south of the leader spot, it could also be part of an
emerging reversed polarity region as indicated by magnetograms.
Region 11093 decayed slowly and simplified magnetically. Further C flares are possible. Flare: long duration C1.3 event peaking at 21:35 UTC.
New region 11094 emerged in the northwest quadrant. Actually a spot was observed in this region already on August 2 but disappeared the next day.
New region 11095 rotated into view at the southeast limb on August 4 and was numbered the next day by NOAA/SWPC. All spots have the same polarity.
August 3-5: No obviously Earth directed CMEs were seen in LASCO or STEREO images.
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 small, recurrent trans equatorial coronal hole (CH416) was Earth facing on August 5.
Image courtesy of SDO (NASA) and the AIA consortium. Annotations are my own. The darkest areas on the solar disk are likely coronal holes.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over high and upper middle latitudes is poor. Propagation on long distance northeast-southwest paths is poor to fair.
The geomagnetic field is expected to be quiet to unsettled on August 6-9, on August 8-9 due to effects from CH416.
|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.
Compare to the previous day's image
Data for all numbered solar regions according to the Solar Region Summary provided by NOAA/SWPC. 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 SWPC or where SWPC has observed no spots. SWPC active region numbers in the table below and in the active region map above are the historic SWPC/USAF numbers.
|Active region||Date numbered||Spot count||Location at midnight||Area||Classification||SDO (NASA) / AIA 4500
|11094||2010.08.05||7||6||N25W58||0050||CSO||CRO||formerly region S795|
|11095||2010.08.05||2||3||S18E46||0010||BXO||AXX||formerly region S797|
|Total spot count:||14||16|
|Month||Average measured solar flux||International sunspot number (SIDC)||Smoothed sunspot number||Average ap
cycle 23 sunspot max.
|2008.07||65.7 (SF minimum)||0.5||2.8 (-0.4)|
|2009.07||68.2||3.2||3.6 (+0.9)||5.49 / 4.55|
|2009.08||67.3||0.0||4.8 (+1.2)||5.70 / 4.89|
|2009.09||70.5||4.3||6.2 (+1.4)||3.88 / 3.61|
|2009.10||72.6||4.8||7.1 (+0.9)||3.66 / 3.56|
|2009.11||73.6||4.1||7.6 (+0.5)||2.45 / 2.63|
|2009.12||76.7||10.8||8.3 (+0.7)||1.41 / 1.92|
|2010.01||81.1||13.2||9.3 (+1.0)||2.93 / 3.07|
|2010.02||84.7||18.8||(10.6 predicted, +1.3)||4.15 / 4.61|
|2010.03||83.4||15.4||(12.3 predicted, +1.7)||4.58 / 4.65|
|2010.04||75.9||7.9||(13.9 predicted, +1.6)||10.22 / 10.24|
|2010.05||73.8||8.8||(15.3 predicted, +1.4)||9.18 / 8.15|
|2010.06||72.5||13.5||(16.7 predicted, +1.4)||8.17 / 6.85|
|2010.07||79.8||16.1||(18.3 predicted, +1.6)||6.31|
|2010.08||80.6 (1)||4.0 (2)||(19.5 predicted, +1.2)||(16.13)|
1) Running average based on the
daily 20:00 UTC observed solar flux
value at 2800 MHz.
2) Current impact on the monthly sunspot number based on the Boulder (NOAA/SWPC) sunspot number (accumulated daily sunspots / month days). The official international sunspot number is typically 30-50% lower.
3) Running average based on the daily SWPC ap indices. Values in red are based on the official NGDC ap indices.
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.