Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 04 Sep 2008

By SpaceRef Editor

September 5, 2008

Filed under Earth, Space and Naval Warfare Systems Command, Space Weather Solar-Geophysical Activity, US

Product: Report of Solar-Geophysical Activity
Issued: 2008 Sep 04 2200 UTC
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Weather Prediction Center and the U.S. Air Force.

Joint USAF/NOAA Report of Solar and Geophysical Activity SDF Number 248 Issued at 2200Z on 04 Sep 2008

IA. Analysis of Solar Active Regions and Activity from 03/2100Z to 04/2100Z: Solar activity was very low. No flares occurred during the past 24 hours. The solar disk continues to be spotless.

IB. Solar Activity Forecast: Solar activity is expected to be very low.

IIA. Geophysical Activity Summary 03/2100Z to 04/2100Z: The geomagnetic field was initially quiet to unsettled, but activity increased to minor to major storm levels from 0000-0600Z. Active levels prevailed from 0600-1500Z, after which conditions decreased to unsettled levels. The activity was driven by a prolonged period of southward Bz (about -10 nT) occurring together with elevated solar wind speeds. Solar wind velocity continued to rise during the past 24 hours with day-end values near 600 km/s. The solar wind signatures are generally consistent with a high speed stream from a coronal hole. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels during the past 24 hours.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be unsettled to active for the first day (05 September) as the high speed wind stream is expected to continue. Conditions should gradually decline to predominantly unsettled for the second day (06 September) and quiet to unsettled for the third day (07 September).

III. Event Probabilities 05 Sep-07 Sep