Last major update issued on February 16, 2005 at 04:10 UTC.
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The geomagnetic field was quiet on February 15. Solar wind speed ranged between 336 and 436 km/sec. Early in the day the solar wind was under the influence of a low speed stream from CH146. Late in the day and early on February 16 the stream from CH145 arrived.
Solar flux measured at 20h UTC on 2.8 GHz was 121.7. The planetary
A
index was 5 (STAR Ap - based on the mean of three hour interval ap
indices: 4.6).
Three hour interval K indices: 11201122 (planetary), 11211101 (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 1 C class event was recorded during the day.
Region 10733 decayed slowly and quietly.Spotted regions not numbered by NOAA/SEC:
[S513] This region emerged to the northwest of region 10735 on February 15. This region has penumbra on both
polarities. Location at midnight: S04E03.
[S514] A new region emerged in the southeast quadrant on February 15. Location at midnight: S08E56
February 13: A CME observed after a C2.7 flare in region 10733 at 10:47 UTC could have geoeffective components.
February 14-15: No obvious fully or partly Earth directed CMEs
were 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 coronal hole (CH145) in the northern hemisphere was in a geoeffective position on February 13-15.
Processed SOHO/EIT 284 image at 13:06 UTC on February 15. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to active on February 16 due to effects from CH145. Unsettled to active conditions are likely on February 17-18 with a possibility of minor storm intervals.
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 to 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 Vibración (Venezuela). Only a few North American stations were noted with weak signals, amongst them WWZN on 1510 kHz.
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 |
---|---|---|---|---|---|---|---|
10730 | 2005.02.04 | S19W70 | plage | ||||
10732 | 2005.02.06 | 4 | N08W60 | 0020 | BXO | spotless for the second consecutive day | |
10733 | 2005.02.07 | 6 | 8 | S08W26 | 0180 | DAO | |
10734 | 2005.02.09 | 4 | 7 | S04W10 | 0070 | CSO |
classification was CAO at midnight |
10735 | 2005.02.10 | 15 | 18 | S08E06 | 0420 | CKO | beta-gamma |
S509 | emerged on 2005.02.09 |
S07W70 | plage | ||||
S511 | emerged on 2005.02.11 |
S06W19 | plage | ||||
S512 | emerged on 2005.02.14 |
S04W57 | plage | ||||
S513 | emerged on 2005.02.15 |
4 | S04E03 | 0040 | DAO | ||
S514 | emerged on 2005.02.15 |
2 | S08E56 | 0010 | BXO | ||
Total spot count: | 29 | 39 | |||||
SSN: | 69 | 89 |
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) |
2003.12 | 114.9 | 46.5 | 54.8 (-1.9) |
2004.01 | 114.1 | 37.3 | 52.0 (-2.8) |
2004.02 | 107.0 | 45.8 | 49.3 (-2.7) |
2004.03 | 112.0 | 49.1 | 47.1 (-2.2) |
2004.04 | 101.2 | 39.3 | 45.5 (-1.6) |
2004.05 | 99.8 | 41.5 | 43.9 (-1.6) |
2004.06 | 97.4 | 43.2 | 41.7 (-2.2) |
2004.07 | 119.1 | 51.0 | 40.3 (-1.4) |
2004.08 | 109.6 | 40.9 | (38.9 predicted, -1.4) |
2004.09 | 103.1 | 27.7 | (36.6 predicted, -2.3) |
2004.10 | 105.9 | 48.4 | (34.4 predicted, -2.2) |
2004.11 | 113.2 | 43.7 | (32.5 predicted, -1.9) |
2004.12 | 94.5 | 17.9 | (30.2 predicted, -2.3) |
2005.01 | 102.2 | 31.3 | (27.6 predicted, -2.6) |
2005.02 | 102.8 (1) | 30.7 (2) | (25.2 predicted, -2.4) |
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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