Correlation of upper‐atmospheric ⁷Be with solar energetic particle events

Production and behavior of beryllium 7 radionuclide in the upper atmosphere

“…Although 7 Be produced in the upper atmosphere by solar protons associated with this event was not reported, correlation of upper-atmospheric 7 Be with solar proton events was found from the observation above 320 km altitudes in 1996-1999(Phillipes et al, 2001. However, the contribution of solar protons to the global average production rate is less than a few % of that of GCR protons.…”

Short‐term production and synoptic influences on atmospheric 7Be concentrations

“…Although the enhanced production of nuclei due to SEPs in the uppermost atmosphere can be directly observed from satellites [ Phillips et al , 2001; Share et al , 2002], the effect in the lower atmosphere needs to be studied. In order to resolve the SEP effect, we compare the results of the “SEP” and “no SEP” runs of the 7 Be production/transport model, which are identical to each other in all respects except for including/ignoring the additional 7 Be production by the SEP event on 20 January 2005 (see section 2.3).…”

A model of the secondary radiation belt

“…For example, atmospheric 14 C, used in radiocarbon dating, forms in cosmic ray interactions with the upper atmosphere, but the significance of a contribution from the radiation belt source is unknown, and similarly for 10 Be obtained from polar ice cores and used to study solar activity and cosmic ray modulation [ Solanki et al , 2004]. High 7 Be concentrations in the upper atmosphere have been attributed to cosmic ray and solar particle interactions [ Phillips et al , 2001], while a secondary radiation belt source has again not been considered. Radiation belt trapping of the secondary particles is not required for them to contribute to atmospheric concentrations, which are therefore determined by the source functions averaged over all secondary directions.…”