Last update issued on August 29, 2003 at 04:00 UTC.
[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update August 18, 2003)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update August 18, 2003)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update August
18, 2003)]
[Historical solar and geomagnetic data charts 1954-2003 (last update July 23, 2003)]
[Archived reports (last update August 28, 2003)]
The geomagnetic field was unsettled to active on August 28. Solar wind speed ranged between 400 and 489 km/sec, probably under the influence of a weak stream from coronal hole CH53.
Solar flux measured at 20h UTC on 2.8 GHz was 118.7. The planetary A
index was 18 (STAR Ap - based on the mean of three hour interval ap indices: 18.6).
Three hour interval K indices: 34443333 (planetary), 34443433 (Boulder).
The background x-ray flux is at the class B3 level.
At midnight there were 11 spotted regions on the visible disk. Solar flare activity was low. A total of 3 C class events was recorded during the day.
Region 10441 decayed quickly and could become spotless today or tomorrow..
Region 10442 decayed and lost the leader spots.
Region 10444 decayed slowly and quietly.
Region 10445 decayed losing spots and penumbral area. Flares: C1.3 at 13:35 (there
was activity at the southeast limb at the same time) and C1.4 at 17:26 UTC.
Region 10446 decayed and could become spotless today.
New region 10447 emerged in the northeast quadrant to the north of region 10444 on August 27 and was numbered the next day
by SEC. Slow decay was observed on August 28.
New region 10448 emerged on August 26 in the northeast quadrant and numbered two days later by SEC. The region developed
slowly both on August 27 and 28.
New region 10449 rotated into view on August 27 at the southeast limb and was numbered the next day by SEC. No significant
changes were observed on August 28. Flare: C1.0 at 08:42 UTC.
Spotted regions not numbered by NOAA/SEC:
[S242] This region emerged in the southwest quadrant on August 28. Location at
midnight: S11W53.
[S243] A new region emerged in the southeast quadrant on August 28. Location at midnight: S08E17.
[S244] A new region rotated into view at the southeast limb on August 28 trailing region 10449. While this region currently
appears to be a separate region it could be part of region 10449. Location at midnight: S17E79.
August 26-28: No potentially geoeffective CMEs observed.
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 coronal hole (CH54) in the northern hemisphere will rotate into a geoeffective position on August 30-31.
Processed GOES SXI coronal structure image at 00:00 UTC on August 29. Base SXI image courtesy of NOAA/SEC. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to active until September 1. On September 2-3 a high speed stream from coronal hole CH54 will likely cause unsettled to minor storm conditions.
Long distance low frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor. Propagation along north-south paths is poor. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant station tonight: Radio Vibración (Venezuela).]
| 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.
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.
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.
| Solar region | Date numbered | SEC spot count |
STAR spot count |
Location at midnight | Area | Classification | Comment |
|---|---|---|---|---|---|---|---|
| 10436 | 2003.08.17 | 4 | N07W80 | 0060 | CRO | spotless | |
| 10441 | 2003.08.21 | 11 | 6 | N14W47 | 0040 | DAO |
classification was CSO at midnight, area 0020 |
| 10442 | 2003.08.22 | 3 | 2 | S13W06 | 0080 | CSO |
classification was HSX at midnight |
| 10443 | 2003.08.22 | N14W72 | plage | ||||
| 10444 | 2003.08.25 | 10 | 9 | N09W06 | 0060 | DAO | |
| 10445 | 2003.08.25 | 11 | 7 | N03W04 | 0060 | DAO | |
| 10446 | 2003.08.27 | 2 | 1 | S23E23 | 0020 | CRO |
classification was AXX at midnight, area 0010 |
| 10447 | 2003.08.28 | 5 | 5 | N16W05 | 0020 | CSO | formerly region S240 |
| 10448 | 2003.08.28 | 7 | 13 | N19E34 | 0050 | CSO |
formerly region S239 classification was DAO at midnight, area 0080 |
| 10449 | 2003.08.28 | 3 | 5 | S16E69 | 0080 | DAO | formerly region S241 |
| S237 | emerged on 2003.08.24 |
N24W64 | plage | ||||
| S242 | emerged on 2003.08.28 |
4 | S11W53 | 0020 | CSO | ||
| S243 | emerged on 2003.08.28 |
1 | S08E17 | 0020 | HSX | ||
| S244 | visible on 2003.08.28 |
1 | S17E79 | 0030 | HSX | ||
| Total spot count: | 56 | 54 | |||||
| SSN: | 146 | 164 | |||||
| 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) |
| 2002.07 | 173.5 | 99.6 | 102.7 (-3.5) |
| 2002.08 | 183.6 | 116.4 | 98.7 (-4.0) |
| 2002.09 | 175.8 | 109.6 | 94.6 (-4.1) |
| 2002.10 | 167.0 | 97.5 | 90.5 (-4.1) |
| 2002.11 | 168.7 | 95.5 | 85.2 (-5.3) |
| 2002.12 | 157.2 | 80.8 | 82.0 (-3.2) |
| 2003.01 | 144.0 | 79.7 | 81.0 (-1.0) |
| 2003.02 | 124.5 | 46.0 | (77.2 predicted, -3.8) |
| 2003.03 | 131.4 | 61.1 | (71.5 predicted, -5.7) |
| 2003.04 | 126.4 | 60.0 | (66.6 predicted, -4.9) |
| 2003.05 | 115.7 | 55.2 | (61.7 predicted, -4.9) |
| 2003.06 | 129.3 | 77.4 | (57.7 predicted, -4.0) |
| 2003.07 | 127.7 | 85.0 | (54.1 predicted, -3.6) |
| 2003.08 | 123.0 (1) | 102.9 (2) | (52.3 predicted, -1.8) |
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 sources noted in solar links. All time references are to the UTC day. Comments and suggestions are always welcome.
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