Last update issued on August 30, 2003 at 04:10 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 quiet to active on August 29. Solar wind speed ranged between 427 and 677 km/sec under the influence of a high speed stream from coronal hole CH53.
Solar flux measured at 20h UTC on 2.8 GHz was 116.3. The planetary A
index was 15 (STAR Ap - based on the mean of three hour interval ap indices: 15.6).
Three hour interval K indices: 12143443 (planetary), 22243443 (Boulder).
The background x-ray flux is at the class B3 level.
At midnight there were 10 spotted regions on the visible disk. Solar flare activity was low. A total of 1 C class event was recorded during the day.
Region 10441 decayed further and had only a single small spot left at the end of the day.
Region 10442 was quiet and stable.
Region 10444 decayed slowly and quietly.
Region 10445 decayed slowly and quietly.
Region 10447 decayed and could become spotless today.
Region 10448 was quiet and displayed only minor changes in the layout of the spots.
Region 10449 was quiet and unchanged.
New region 10450 rotated into view at the southeast limb on August 28 and was numbered the next day by SEC. Flare: C1.0 at 19:59 UTC.
Spotted regions not numbered by NOAA/SEC:
[S245] This region emerged in the northwest quadrant on August 29. Location at midnight: N24W32.
[S246] A new region emerged near the center of the visible disk on August 29. Location at midnight: N10W05.
August 27-29: 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 with a trans equatorial extension, will rotate into a geoeffective position on August 29- September 2.
Processed GOES SXI coronal structure image at 00:00 UTC on August 30. 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 the first half of September 1. On September 1-5 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 stations tonight: Radio Vibración (Venezuela) and Radio Cristal del Uruguay].
|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
|Location at midnight||Area||Classification||Comment|
classification was AXX
at midnight, area 0000
classification was CSO
classification was HRX
classification was DSO
at midnight, area 0000
classification was HRX
|10450||2003.08.29||1||1||S18E66||0060||HSX||formerly region S244|
formerly region S242
formerly region S243
|Total spot count:||32||45|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|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||122.8 (1)||107.1 (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.