Last major update issued on June 6, 2005 at 04:35 UTC.
[Solar and
geomagnetic data - last month (updated daily)]
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[Solar cycles 21-23
(last update June 4, 2005)]
[Solar cycles 1-20]
[Graphical comparison
of cycles 21, 22 and 23 (last update June 4, 2005)]
[Graphical
comparison of cycles 2, 10, 13, 17, 20 and 23 (last update June 4, 2005)]
[Historical solar and
geomagnetic data charts 1954-2004 (last update February 1, 2005)]
[Archived reports
(last update June 4, 2005)]
The geomagnetic field was quiet to minor storm on June 5. Solar wind speed ranged between 461 and 689 km/sec under the influence of a high speed stream from CH169.
Solar flux measured at 20h UTC on 2.8 GHz was 105.4. The planetary
A
index was 20 (STAR Ap - based on the mean of three hour interval ap
indices: 20.1).
Three hour interval K indices: 43532333 (planetary), 43532233 (Boulder).
The background x-ray flux is at the class B2 level.
At midnight there were 5 spotted regions on the visible solar disk. The solar flare activity level was low. A total of 2 C class events was recorded during the day.
Region 10772 decayed significantly and lost both spots and penumbral area. Flare:
C1.2 at 03:28 UTC.
Region 10773 did not change much and was quiet.
Region 10774 developed penumbra on both polarities.
Region 10775 developed slowly and quietly.
New region 10776 rotated partly into view at the southeast limb on June 4 and was numbered the next day by SEC. The region
has an interesting magnetic field layout and could produce M class flares. Flare: C3.5 long
duration event peaking at 13:50 UTC.
June 3-5: No obvious fully or partly Earth directed CMEs were observed in LASCO images.
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 large, recurrent coronal hole (CH169) in the northern hemisphere with a trans equatorial extension was in an Earth facing position on June 1-3.
Processed SOHO/EIT 284 image at 01:06 UTC on June 6. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to active on June 6 due to a diminishing high speed stream from CH169. Quiet to unsettled conditions are likely on June 7-8.
| 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 very poor. Propagation along long distance north-south paths is poor. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: Radio Cristal del Uruguay. On other frequencies some stations from Uruguay and Argentina were noted with mostly weak or very weak signals.
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 spot count |
STAR spot count |
Location at midnight | Area | Classification | Comment |
|---|---|---|---|---|---|---|---|
| 10769 | 2005.05.28 | S06W18 | plage | ||||
| 10772 | 2005.05.31 | 15 | 14 | S18W18 | 0110 | DSO | |
| 10773 | 2005.06.01 | 6 | 8 | S13E23 | 0120 | DAO | location: S13E21 |
| 10774 | 2005.06.04 | 2 | 7 | N04W21 | 0010 | HRX |
classification was DAO at midnight, area 0050 location: N05W19 reversed polarities |
| 10775 | 2005.06.04 | 1 | 4 | N12E61 | 0160 | HSX | classification was CAO at midnight, area 0220, location: N11E59 |
| 10776 | 2005.06.05 | 3 | 10 | S05E71 | 0230 | DAO |
formerly region S554 area was 0400 at midnight |
| Total spot count: | 27 | 43 | |||||
| SSN: | 77 | 93 | |||||
| Month | Average solar flux at Earth |
International sunspot number | Smoothed sunspot number |
|---|---|---|---|
| 2000.04 | 184.2 | 125.5 | 120.8 cycle 23 sunspot max. |
| 2000.07 | 202.3 | 170.1 | 119.8 |
| 2001.12 | 235.1 | 132.2 | 114.6 (-0.9) |
| 2004.04 | 101.2 | 39.3 | 45.5 (-1.6) |
| 2004.05 | 99.8 | 41.5 | 43.8 (-1.7) |
| 2004.06 | 97.4 | 43.2 | 41.6 (-2.2) |
| 2004.07 | 119.1 | 51.1 | 40.2 (-1.4) |
| 2004.08 | 109.6 | 40.9 | 39.2 (-1.0) |
| 2004.09 | 103.1 | 27.7 | 37.5 (-1.7) |
| 2004.10 | 105.9 | 48.0 | 35.9 (-1.6) |
| 2004.11 | 113.2 | 43.5 | 35.3 (-0.6) |
| 2004.12 | 94.5 | 17.9 | (34.8 predicted, -0.5) |
| 2005.01 | 102.2 | 31.3 | (32.8 predicted, -2.0) |
| 2005.02 | 97.2 | 29.1 | (30.4 predicted, -2.4) |
| 2005.03 | 89.9 | 24.8 | (28.8 predicted, -1.6) |
| 2005.04 | 86.0 | 24.4 | (26.9 predicted, -1.9) |
| 2005.05 | 99.3 | 42.6 | (24.3 predicted, -2.6) |
| 2005.06 | 97.6 (1) | 12.3 (2) | (22.8 predicted, -1.5) |
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.
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