First detection of flare from total solar irradiance observations

An analysis of total solar irradiance data has allowed researchers to make the first detections of a solar flare from radiation-sensing satellites. Woods et al. report that total solar irradiance dropped by an unprecedented 0.34 percent during the strong solar storm in October-November 2003, because of large, dark sunspots observed by two NASA satellite missions.

They also present data showing marked short-term solar radiation increases during one of the strongest X-class events seen during the event. The two-week solar storm included unusually powerful flare and particle eruptions that produced 44 M (moderate)-class flares and 11 X (extreme)-class flares, including a powerful X28-sized flare.

The satellite data provide the first definitive measurement of a flare detected using total solar irradiance instruments, which also recorded unexpected ultraviolet variations over a broad wavelength from the Sun’s storm.

Title: Solar irradiance variability during the October 2003 solar storm period