Solar Influence on Ozone Variations over ENSO Regions

The most important source of ENSO (El-Nino Southern Oscillation) excitation is the influence of harmonics of solar activity cycles. The solar activity is reveling mainly by the Total Solar Irradiance (TSI) variations, solar wind and variations of solar magnetic field. While the TSI variations affect directly earth surface temperature, the solar wind and magnetic field modulate changes of the heliosphere, geomagnetic field and cosmic ray variations. The cosmic ray variations drive ozone production in low stratosphere near the tropopause, and next a chain process affects surface temperature. These effects are proved in polar and ENSO regions. In previous studies, a strong correlation has been found between ozone and El Nino variations; and between the variations of indices of N-S solar asymmetry and Nino 3.4. So, the possible transmitter between solar signals and ENSO event is low stratospheric ozone, whose variations are affected by solar activity. The solar influence on ozone variations over ENSO regions is investigated by means of time series of solar activity indices and ozone variations at 70 HPa over Nino 3.4 regions around equatorial part of Pacific Ocean. The common harmonics of solar and ozone cycles are determined by means of recently developed Method of Partial Fourier Approximation, where the trigonometric coefficients are estimated by the Method of Least Squares. The results of common frequency bands with interannual, decadal and centennial periodicity of solar and ozone data may improve models of solar influence on Pacific temperature anomalies and recent climate change.