:Product: Weekly Highlights and Forecasts :Issued: 2003 Mar 11 2212 UTC # Prepared by the US Dept. of Commerce, NOAA, Space Environment Center # Product description and SEC contact on the Web # http://www.sec.noaa.gov/weekly.html # # Weekly Highlights and Forecasts # Highlights of Solar and Geomagnetic Activity 03 - 09 March 2003 Solar activity was at very low to low levels. The period began with low level activity on 03 March, due to a long duration C2.4 flare at 2105 UTC from a spotless plage field near S27E72. A partial halo CME associated with this long duration event was observed in LASCO imagery. Region 296 (N11, L=179, class/area Dki/650 on 04 March) was the largest and most complex region during the period and the source of minor C-class activity early in the period. This region grew to a moderate size spot group and on 03 March developed a beta-gamma magnetic configuration. On 05 March, Region 296 entered a gradual decay phase. Activity was at very low levels on 04 – 07 March. Late in the period Region 306 (N05, L= 76, class/area Dko/540 on 09 March) rotated onto the visible disk and produce low level activity on 08 March. This region exhibited steady growth through the end of the period and developed a beta magnetic configuration. Region 304 (S11, L-168, class/area Dao/070 on 09 March) was the source of low level activity on 09 March with four C-class flares. For flare times and magnitudes please refer to the Energetic Event and Flare lists. Solar wind data were available from the NASA Advanced Composition Explorer (ACE) spacecraft for most of the summary period. The period began with a recurrent coronal hole early on 03 March and into 04 March. Solar wind velocity increased to near 550 km/s with peak values near 650 km/s. The Bz component of the interplanetary magnetic field exhibited southern oscillations near minus 15 nT. Solar wind velocity decreased to 450 km/s on 05 March when a second high speed stream increased velocity back to near 550 km/s. For the remainder of the period, 06 – 09 March solar wind velocity was in gradual decline and ended the period near 400 km/s. Bz remained in an oscillating pattern between plus and minus 8 nT. There were no greater than 10 MeV proton events at geo-synchronous orbit during the summary period. The greater than 2 MeV electron flux at geo-synchronous orbit reached high levels on 03 and 05 – 08 March. The geomagnetic field was at quiet to minor storm levels. Late on 03 March, a recurrent coronal hole in the northwest quadrant rotated into a geo-effective position resulting in active to minor storm levels on 03 – 04 March. A second high speed stream occurred late on 05 March and resulted in unsettled to active conditions on 05 – 06 March with one period of minor storm conditions. Activity on 07 – 09 March was mostly quiet to unsettled with two separate periods of isolated active conditions due to negative fluctuations in Bz. Forecast of Solar and Geomagnetic Activity 12 March - 07 April 2003 Solar activity is expected to be at low levels with a slight chance of moderate activity. Regions 296 and 306 have the potential for isolated M-class activity during the period. On 20 – 26 March activity is expected to be at very low to low levels as both Region 296 and Region 306 are transiting the backside of the sun. No greater than 10 MeV proton events are expected during the forecast period. The greater than 2 MeV electron flux may reach high levels on 19 – 24 March, 27 – 28 March and again on 04 – 06 April due to returning coronal holes. The geomagnetic field is expected to be at quiet to major storm levels. A large southern coronal hole is expected to return to a geo-effective position on 15 – 21 March and is expected to produce unsettled to isolated minor storm conditions. Two smaller but more intense coronal holes are due on 25 – 27 March and 30 – 31 March and are expected to produce active to isolated major storm levels. A weak but persistent coronal hole is expected on 01 – 04 April with unsettled to isolated active conditions. .