Accession Number : ADA570148


Title :   Size Distributions of Solar Flares and Solar Energetic Particle Events (POSTPRINT)


Descriptive Note : Journal article


Corporate Author : AIR FORCE RESEARCH LAB KIRTLAND AFB NM SPACE VEHICLES DIRECTORATE


Personal Author(s) : Cliver, E W ; Ling, A G ; Belov, A ; Yashiro, S


Full Text : http://www.dtic.mil/get-tr-doc/pdf?AD=ADA570148


Report Date : 20 Sep 2012


Pagination or Media Count : 8


Abstract : We suggest that the flatter size distribution of solar energetic proton (SEP) events relative to that of flare soft X-ray (SXR) events is primarily due to the fact that SEP flares are an energetic subset of all flares. Flares associated with gradual SEP events are characteristically accompanied by fast (greater than or equal to 1000 km s [expn -1]) coronal mass ejections (CMEs) that drive coronal/interplanetary shock waves. For the 1996 2005 interval, the slopes (values) of power-law size distributions of the peak 1-8 Angstrom fluxes of SXR flares associated with (a) 10 MeV SEP events (with peak fluxes greater than or equal to 1 pr cm [expn -2] s [expn-1] sr [expn]-1) and (b) fast CMEs were 1.3-1.4 compared to 1.2 for the peak proton fluxes of 10 MeV SEP events and 2 for the peak 1-8 Angstrom fluxes of all SXR flares. The difference of 0.15 between the slopes of the distributions of SEP events and SEP SXR flares is consistent with the observed variation of SEP event peak flux with SXR peak flux.


Descriptors :   *SOLAR FLARES , CORONAL MASS EJECTIONS , EMISSION , GAMMA RAYS , PARTICLE SIZE , SOLAR ENERGY , X RAYS


Subject Categories : Astrophysics


Distribution Statement : APPROVED FOR PUBLIC RELEASE