Modulation Of Solar Activity Change On Tropical Convection

Using the 1975～2013 Outgoing Longwave Radiation data, multiple 1954～2013 monthly reanalysis data and the 1954～2013 10.7cm Flux (F10.7) index, which represent the intensity of solar activity, this paper analyzed the modulation of solar activity on tropical Pacific, tropical Indian Ocean and tropical Atlantic Ocean. By correlation analysis, empirical orthogonal functions (EOF), compositing analysis, and spectral analysis, this paper drew these conclusions:(1) In the boreal summer of the second years following high solar years, the convection over the tropical western Pacific presents a dipole mode, which is independent of El Nino and Southern Oscillation (ENSO), along with the eastward shifting of deep convection and the ascending of Walker circulation. The possible mechanism is that solar activity causes lagged sea surface temperature (SST) mode modulates vertical air temperature, and the vertical air temperature anomaly affects the convection. (2) In the boreal winter of high solar years, the convection over the tropical southern Indian Ocean, the west side of Australia and the south of Arabian Peninsula is enhanced. (3) In the boreal winter and summer of high solar years, the convection over the tropical southern Atlantic Ocean is enhanced.