SORCE TIM Observations of Recent Flares (10/03-11/03)

The Total Irradiance Monitor (TIM) on board the SOlar Radiation and Climate Experiment launched in January 2003 has recorded two unprecedented events in total solar irradiance (TSI): 1) The decrease of 0.34% (4.5 W/m2) in TSI due to the passage of two large sunspot groups on 29 Oct. is larger than any short-term TSI decrease in the composite 25-year spacecraft TSI record.

2) The X17 flare on 28 Oct. caused a sudden 270 ppm increase in TSI. To our knowledge, this is the first time a flare has been observed in TSI measurements.