Last major update issued on August 2, 2006 at 04:35 UTC.
geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update July 19, 2006)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update July 19, 2006)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update July 19, 2006)]
[Historical solar and geomagnetic data charts 1954-2005 (last update March 3, 2006)]
[Archived reports (last update July 9, 2006)]
The geomagnetic field was quiet to active on August 1. Solar wind speed ranged between 482 and 716 km/s (all day average 572 km/s - increasing 83 km/s over the previous day) under the influence of a high speed stream from CH234.
Solar flux measured at 20h UTC on 2.8 GHz was 72.8. The planetary A index
was 12 (STAR Ap - based on the mean of three hour interval ap
Three hour interval K indices: 24432212 (planetary), 24433211 (Boulder).
The background x-ray flux is at 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 10902 developed slowly and was quiet.
July 30 - August 1: 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 coronal hole (CH235) in the southern hemisphere (with a trans equatorial extension) will likely rotate into an Earth facing position on August 3-4.
Processed SOHO/EIT 284 image at 01:06 UTC on August 2. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to unsettled on August 2 due to a high speed stream from CH234 and mostly quiet on August 3-5. A high speed stream from CH235 could arrive on August 6 and cause quiet to active conditions that day and on August 7.
|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 poor. Propagation on long distance northeast-southwest paths is poor. A few stations from Venezuela (1290, 1470 and 1500 kHz), Colombia, Cuba (670 and 1180 kHz), USA (surprisingly good signal from 1130 WBBR) and Canada (Newfoundland on 590, 620, 640, 650, 710, 740, 750, 800, 930 kHz) were heard. Southeast Brazil and Argentina were represented by weaker than average signals from the most often heard stations.
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|
|10902||2006.07.30||1||3||S08W62||0010||AXX||classification was CSO, area 0020 at midnight|
|Total spot count:||1||3|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2006.02||76.5||4.7||(18.4 predicted, -2.4)|
|2006.03||75.4||10.8||(16.6 predicted, -1.8)|
|2006.04||89.0||30.2||(15.9 predicted, -0.7)|
|2006.05||80.9||22.2||(15.1 predicted, -0.8)|
|2006.06||76.5||13.9||(12.9 predicted, -2.2)|
|2006.07||75.7||12.2||(11.4 predicted, -1.5)|
|2006.08||72.8 (1)||0.3 (2)||(11.4 predicted, -0.0)|
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.