Last major update issued on July 7, 2007 at 02:05 UTC.
geomagnetic data - last month (updated daily)]
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[Solar cycles 21-23 (last update June 3, 2007)]
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[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update June 3, 2007)]
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[Archived reports (last update July 1, 2007)]
The geomagnetic field was quiet on July 7. Solar wind speed ranged between 439 and 463 km/s (average speed was 448 km/s, increasing 3 km/s over the previous day).
Solar flux measured at 20h UTC on 2.8 GHz was 73.1. The planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 5.8). Three hour interval K indices: 21111222 (planetary), 22111222 (Boulder).
The background x-ray flux is at the class A8 level.
At midnight there was 1 spotted region on the visible solar disk. The solar flare activity level was low. A single C class event was recorded during the day.
New region 10963 rotated into view at the southeast limb. This region is fairly active and could produce further C flares. Flare: C1.9 at 14:30 UTC.
July 5-7: No obvious fully or partially Earth directed CMEs were observed in incomplete LASCO imagery.
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 coronal hole (CH277) in the southern hemisphere was in an Earth facing position on July 6-7.
Processed STEREO 195 image at 23:25 UTC on July 7. The darkest areas on the solar disk are likely coronal holes.
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor to fair. Propagation on long distance northeast-southwest paths is poor to fair.
Monitoring remarks from a location near N58E06: July 8: A few stations from Newfoundland and the northeastern US were audible at 02h UTC, 1510 WWZN had a fairly good signal.
The geomagnetic field is expected to be quiet on July 8-9. CH277 could cause some unsettled and active intervals late on July 9 and on July 10.
|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/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|
|10961||2007.06.25||2||S08W86||0060||HSX||rotated out of view|
|10963||2007.07.07||1||4||S09E83||0050||AXX||classification was DAO at midnight, area 0100|
|Total spot count:||3||4|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2007.01||83.3||16.9||(11.9 predicted, -0.2)|
|2007.02||77.7||10.6||(11.3 predicted, -0.6)|
|2007.03||72.2||4.8||(10.8 predicted, -0.5)|
|2007.04||72.4||3.7||(10.8 predicted, unchanged)|
|2007.05||74.4||11.7||(10.6 predicted, -0.2)|
|2007.06||73.7||12.0||(10.7 predicted, +0.1)|
|2007.07||72.4 (1)||4.1 (2)||(11.0 predicted, +0.3)|
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.