Last major update issued on June 7, 2004 at 03:10 UTC.
[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update June 2, 2004)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update June 2, 2004)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update June 2, 2004)]
[Historical solar and geomagnetic data charts 1954-2004 (last update April 28, 2004)]
[Archived reports (last update May 30, 2004)]
The geomagnetic field was quiet to active on June 6. Solar wind speed ranged between 458 and 526 km/sec under the influence of a coronal hole flow.
Solar flux measured at 20h UTC on 2.8 GHz was 88.4. The planetary A
index was 11 (STAR Ap - based on the mean of three hour interval ap indices: 12.5).
Three hour interval K indices: 34333232 (planetary), 33332332 (Boulder).
The background x-ray flux is at the class A7 level.
At midnight there were 3 spotted regions on the visible disk. The solar flare activity level was very low. No C class events were recorded during the day.
Region 10621 decayed further and could soon become spotless. This region was the source of a long duration C2.7 event
peaking at 00:44 UTC on June 7.
Region 10627 developed slowly and could produce C flares.
Spotted regions not numbered by NOAA/SEC:
[S413] This region rotated into view at the northeast limb on June 6. Location at midnight: N13E70.
June 4-6: No fully or partly Earth directed CMEs observed. A large full halo CME was observed during the morning of June 4, its source was a few days behind the west limb.
Coronal hole history (since late October 2002)
Compare today's report with the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago
A small recurrent coronal hole (CH100) in the northern hemisphere was in a geoeffective position on June 4.
Processed SOHO/EIT 284 image at 19:05 UTC on June 6. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to unsettled on June 7-9.
|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) Material from a CME is likely to impact 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 along long distance north-south paths is fair. Trans Atlantic propagation conditions are monitored every night on 1470 kHz. Dominant stations tonight: Radio Cristal del Uruguay before 02h UTC, afterwards Radio Vibración (Venezuela) had a good signal until after local sunrise. While some of the stronger stations from Brazil (740, 980, 1350 and 1440 kHz) still had good signals, the number of stations from the southeastern and eastern parts of South America was greatly reduced compared to one day ago. Instead stations from Venezuela were significantly better. Some North American stations were observed as well. As usual 1510 WWZN had the best signal, while 930 CJYQ and 590 VOCM became audible again.
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|
classification was BXO
at midnight, area 0010
classification was DAI
at midnight, area 0070
|Total spot count:||20||21|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2003.12||114.9||46.5||(54.4 predicted, -2.3)|
|2004.01||114.1||37.2||(50.5 predicted, -3.9)|
|2004.02||107.0||46.0||(46.2 predicted, -4.3)|
|2004.03||112.0||48.9||(43.5 predicted, -2.7)|
|2004.04||101.2||39.3||(41.4 predicted, -2.1)|
|2004.05||99.8||41.5||(38.2 predicted, -3.2)|
|2004.06||88.8 (1)||13.0 (2)||(35.3 predicted, -2.9)|
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% less.
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.