Last update issued on February 21, 2003 at 02:20 UTC.
[Solar and geomagnetic data
- last 4 weeks (updated daily)]
[Solar wind and electron
fluence charts (updated daily)]
[Solar cycles 21-23 (last
update February 2, 2003)]
[Solar cycles 1-20]
[Graphical comparison of
cycles 21, 22 and 23 (last update February 2, 2003)]
[Graphical comparison of
cycles 10, 13, 17, 20 and 23 (last update February 2, 2003)]
[Historical solar and geomagnetic
data charts 1954-2002 (last update January 27, 2003)]
[Archived reports (last update February 17, 2003)]
The geomagnetic field was unsettled to active on February 20. Solar wind speed ranged between 517 and 755 km/sec at SOHO under the influence of a high speed stream originating in CH (coronal hole) 21.
Solar flux measured at 20h UTC on 2.8 GHz was 118.3. The planetary A
index was 16 (STAR Ap - based on the mean of three hour interval ap indices: 16.9).
Three hour interval K indices: 33443433 (planetary), 24442333 (Boulder).
The background x-ray flux is at the class B3-B4 level.
At midnight there were 5 spotted regions on the visible disk, 2 of which have not yet been numbered by SEC/NOAA. Solar flare activity was low. A total of 2 C class events was recorded during the day, sub flare activity was high.
Region 10288 developed new trailing spots while the leading spots merged into a larger penumbra.
Region 10289 began to rotate over the northwest limb and appeared to be slowly decaying.
Region 10290 maintained its rapid growth with a weak magnetic delta structure forming in the southwestern part of the
leading penumbra. M class flares are possible. Flares: C1.7 at 02:56 and C1.3 at 17:28 UTC.
Spotted regions not yet numbered by SEC/NOAA:
[S104]: A new region emerged early on February 20 in the southeast quadrant. Location at midnight: S22E17.
[S105]: A new region emerged on February 20 southwest of region S104. Location at midnight: S28E10.
February 18-20: No obviously 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 recurrent, small trans equatorial coronal hole will rotate into a geoeffective position on February 23-24.
Processed SOHO EIT 284 image at 19:06 UTC on February 20. Any black areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to active on February 21 and quiet to unsettled on February 22-24. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is very poor, propagation along north-south paths is fair. [Propagation conditions are currently monitored every night. Main monitoring frequency: 1470 kHz. Dominant station tonight: Radio Vibración (fair signal)]
| 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 SEC/NOAA. 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 |
|---|---|---|---|---|---|---|---|
| 10285 | 2003.02.08 | S12W79 | plage | ||||
| 10288 | 2003.02.15 | 6 | 7 | N13E01 | 0050 | CSO |
classification was DAO at midnight, area 0080 |
| 10289 | 2003.02.18 | 8 | 7 | N10W81 | 0230 | DAO | |
| 10290 | 2003.02.18 | 22 | 35 | N17E18 | 0310 | EAI |
beta-gamma-delta classification was EKI at midnight, area 0450 |
| S100 | emerged on 2003.02.13 |
N11W56 | plage | ||||
| S101 | emerged on 2003.02.15 |
S03W78 | plage | ||||
| S102 | emerged on 2003.02.15 |
S08W25 | plage | ||||
| S104 | emerged on 2003.02.20 |
9 | S22E17 | 0030 | DRO | ||
| S105 | emerged on 2003.02.20 |
3 | S28E10 | 0000 | AXX | ||
| Total spot count: | 36 | 61 | |||||
| SSN: | 66 | 111 | |||||
| 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) |
| 2002.01 | 226.6 | 114.1 | 113.5 (-1.1) |
| 2002.02 | 205.0 | 107.4 | 114.6 (+1.2) |
| 2002.03 | 179.5 | 98.4 | 113.3 (-1.3) |
| 2002.04 | 189.8 | 120.7 | 110.5 (-2.9) |
| 2002.05 | 178.4 | 120.8 | 108.8 (-1.7) |
| 2002.06 | 148.7 | 88.3 | 106.2 (-2.6) |
| 2002.07 | 173.5 | 99.6 | 102.7 (-3.5) |
| 2002.08 | 183.6 | 116.4 | (99.7 predicted, -3.0) |
| 2002.09 | 175.8 | 109.6 | (96.7 predicted, -3.0) |
| 2002.10 | 167.0 | 97.5 | (93.2 predicted, -3.5) |
| 2002.11 | 168.7 | 95.0 | (88.0 predicted, -5.2) |
| 2002.12 | 157.2 | 81.6 | (83.6 predicted, -4.4) |
| 2003.01 | 144.0 | 79.5 | (80.6 predicted, -3.0) |
| 2003.02 | 130.0 (1) | 71.0 (2) | (75.5 predicted, -5.1) |
1) Running average based on the daily 20:00 UT observed solar flux value at 2800
MHz.
2) Unofficial, accumulated value based on the Boulder (SEC/NOAA) sunspot number. The official
international sunspot number is typically 25-45% less.
This report has been prepared by Jan Alvestad. It is based partly on my own observations and interpretations, 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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