Analysis of variations in the nitrogen oxide content in the polar atmosphere of the northern hemisphere during the solar proton flare of July 14, 2000, based on the UARS satellite data

Nitrogen oxides, produced as a result of ionizing proton impacts, have long lifetimes and substantially affect the ozone balance. Photochemical models give an increased production level of nitrogen oxides during solar proton flares. The usage of an increased NO production effectiveness value (molecule number per each ion pair) during increased ionization of the atmosphere in models can be among the causes. This value has been estimated based on satellite observational data. Data on the solar proton fluxes and the composition of the atmosphere have been used. The period of the proton event of July 14, 2000, has been considered. The NO production effectiveness, obtained when the observational data were analyzed, was much smaller than the value obtained previously theoretically. The causes of these differences should be studied additionally.