:Product: Weekly Highlights and Forecasts :Issued: 2004 Feb 17 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 09 - 15 February 2004 Solar activity ranged from very low to low levels. The period began at low levels on 09 February with nine C-class flares originating from Region 554 (S08, L=305, class/area Dhc/310 on 09 February). The largest of these flares was a C9 at 1102 UTC. Region 554 reached 310 millionths on 09 February and developed a beta-gamma-delta magnetic configuration. However, the delta configuration was no longer apparent by 10 February, and decayed to a simple beta configuration by 11 February. Activity was at very low levels from 10 – 15 February. On 12 – 13 February, both GOES XRS and NOAA SXI imager observed no flares. Toward the end of the period, five small spot groups appeared on the disk, but as of yet have not produced any flares. Solar wind data were available from the NASA Advanced Composition Explorer (ACE) spacecraft during most of the summary period. Late on 11 February, IMF total field increased to 15 nT and Bz decreased to –12 nT marking the beginning of a corotating interaction region (CIR). The CIR gave way to a coronal hole high speed stream on 12 February as solar wind speed increased to near 700 km/s. Solar wind decreased to near 630 km/s and remained there through 14 February. An increase in wind speed to near 800 km/s was observed on 15 February, before a steady decline began. The period ended with solar wind speed at 600 km/s and decreasing. There were no greater than 10 MeV proton events at geosynchronous orbit during the summary period. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels on 09 February and again on 12 – 15 February. The geomagnetic field ranged from quiet to major storm levels. Quiet to unsettled conditions were observed on 09 – 10 February. Isolated major storm levels were observed on 11 February due to the CIR and the onset of a large coronal hole. Activity remained at unsettled to minor storm levels on 12 February and decreased to active levels on 13 – 14 February. Unsettled to active condition dominated 15 February except for one period of isolated minor storm conditions due the increased solar wind speed. Forecast of Solar and Geomagnetic Activity 18 February - 15 March 2004 Solar activity is expected to range from very low to moderate levels. Predominantly very low to low activity levels are expected from late February through early March. Mostly low level activity may return by mid March. No greater than 10 MeV proton event are expected during the period. The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach high levels on 24 February – 05 March and again on 11 – 15 March, due to recurrent coronal holes. Geomagnetic activity is expected to range from quiet to minor storm levels. A number of recurrent coronal hole high speed streams are expected between 22 February – 03 March, which will likely produce occasional active to minor storm periods with isolated major storm periods possible. A coronal hole high speed stream is due to return on 09 – 14 March and is expected to produce active to minor storm conditions.