Influence of solar proton events during the declining phase of solar cycle 23 on the total ozone concentration in India

Depletion of ozone under the influence of solar proton events (SPEs) is an important natural phenomenon affecting the middle mesospheric and upper stratospheric ozone content. When the Sun went through the declining phase of its activity in solar cycle 23, it unleashed a series of large eruptions, which were unusually intense flares, and accelerated particles to unprecedented energy levels. The severe impact of these events was felt in the Earth's atmosphere, not only at higher latitudes but also at the middle latitudes and tropics. The impact of nine such SPEs, having different proton flux and time duration on the total ozone content at Indian latitude belts, was studied using the ozone data obtained from Earth Probe Total Ozone Mapping Spectrometer and Ozone Monitoring Instrument. It is observed that, for high proton flux, the depletion in ozone levels extended up to low latitudes. The observed depletion in ozone was found to be higher for longer time duration of the SPE.