Solar Terrestrial Activity Report

Last update issued on March 3, 2003 at 03:40 UTC.

[Solar and geomagnetic data - last 4 weeks (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update March 3, 2003)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update March 3, 2003)]
[Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update March 3, 2003)]
[Historical solar and geomagnetic data charts 1954-2002 (last update January 27, 2003)]
[Archived reports (last update March 3, 2003)]

Recent activity

The geomagnetic field was quiet to active on March 2. Solar wind speed ranged between 351 and 426 km/sec.

Solar flux measured at 18h UTC on 2.8 GHz was 133.3 (the value measured at 20h UTC deviated at lot from the the 18 and 22h UTC measurements). The planetary A index was 14 (STAR Ap - based on the mean of three hour interval ap indices: 14.5).
Three hour interval K indices: 23334333 (planetary), 13333233 (Boulder).

The background x-ray flux is at the class B4 level.

At midnight there were 8 spotted regions on the visible disk, 4 of which have not yet been numbered by SEC/NOAA. Solar flare activity was low. A total of 5 C class events was recorded during the day.

Region 10294 decayed further and could become spotless today or tomorrow.
Region 10295 was quiet and stable.
Region 10296 was mostly quiet and added some small intermediate spots. M class flares are possible. Flare: C1.0 at 13:46 UTC.
Region 10297 did not change much and was quiet.

Spotted regions not yet numbered by SEC/NOAA:
[S113] A new region emerged in the southwest quadrant on March 1. The region developed further on March 2 and may be capable of producing a minor M class flare while rotating over the southwest limb. Location at midnight: S10W78 (southeast of spotless region 10292). Flares: C1.1 at 07:52, C1.1 at 09:27, C1.3 at 10:21 and C1.2 at 10:39 UTC.
[S115] A new region emerged in the southeast quadrant (west of region 10295) on March 2. Location at midnight: S19E18.
[S116] A new region emerged in the northwest quadrant on March 2. Location at midnight: N13W04.
[S117] A new region rotated into view at the southeast limb on March 2. Location at midnight: S25E74.

Coronal mass ejections (CMEs)

February 28-March 2: No obviously geoeffective CMEs observed.

Coronal holes

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 (CH23) in the northern hemisphere with a trans equatorial extension was in a geoeffective position on March 1. A coronal hole (CH24) in the southern hemisphere will be in a geoeffective position on March 2-3.

Processed SOHO EIT 284 image at 01:06 UTC on March 3. Any black areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be quiet to unsettled initially on March 3. During the latter half of the day a high speed stream from coronal hole CH23 is likely to arrive and cause unsettled to active conditions, possibly with isolated minor storm intervals early on. Unsettled to active conditions are likely to persist until March 7 as this high speed coronal hole stream will be overlapped by a high speed stream from CH24. Quiet to unsettled conditions are likely from March 8. 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 poor. [Propagation conditions are currently monitored every night. Main monitoring frequency: 1470 kHz. Dominant station tonight: Radio Vibración (weak 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.

Active solar regions (Recent map)

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.

Monthly solar cycle data

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.