Last major update issued on July 5, 2007 at 03:45 UTC.
geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)
[Solar cycles 21-23 (last update June 3, 2007)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update June 3, 2007)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update June 3, 2007)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports (last update July 1, 2007)]
The geomagnetic field was quiet to active on July 4. Solar wind speed ranged between 462 and 692 km/s (average speed was 562 km/s, increasing 190 km/s over the previous day) under the influence of a high speed stream from CH276.
Solar flux measured at 20h UTC on 2.8 GHz was 72.4. The planetary A index was 16 (STAR Ap - based on the mean of three hour interval ap indices: 16.3). Three hour interval K indices: 44343232 (planetary), 34343221 (Boulder).
The background x-ray flux is below the class A1 level.
At midnight there was 1 spotted region on the visible solar disk. The solar flare activity level was very low. No C class events were recorded during the day.
Region 10961 was quiet and stable.
July 2-4: No obvious fully or partially Earth directed CMEs were observed in 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 new trans equatorial coronal hole (CH276) formed while near the center of the visible solar disk on June 29-30. A recurrent coronal hole (CH277) in the southern hemisphere will likely be in an Earth facing position on July 7.
Processed SOHO/EIT 195 image at 00:00 UTC on July 5. 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 very poor. Propagation on long distance northeast-southwest paths is good.
Monitoring remarks from a location near N58E06: July 5: Many stations from Brazil were audible near LSR with the best signal noted on 1560 kHz. A few stations from Venezuela could be heard as well with 1310 kHz having the best signal.
The geomagnetic field is expected to be quiet to unsettled on July 5 due to effects from CH276 and quiet on July 6-9. CH277 could cause some unsettled and active intervals on July 10-11.
|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||3||2||S09W44||0100||HSX||classification was HAX at midnight|
|Total spot count:||3||2|
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||72.8 (1)||2.2 (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.