The Impact of Solar on the Convection dipole over the Tropical Western Pacific Ocean

The impact of solar activity (F10.7) on tropical Pacific convection in the boreal summer (Jun-Aug) has been studied by analyzing based on reanalysis data. The analysis showed that there was a significant lagged correlation between outgoing long-wave radiation (OLR) over the tropical western Pacific and F10.7 index, with the former lagging the latter by about 1-2 years. The OLR anomaly over the tropical western Pacific and the maritime continent shows a dipole mode in the first and the second year after high solar (HS) years. Furthermore, the first mode of the empirical orthogonal function (EOF) analysis on OLR without ENSO signal is similar to OLR anomaly in the first and the second year after HS years. After correlation analysis and composite analysis of OLR and vertical velocity, we found that this dipole convection mode indicated that the central position of deep convection had been shifted eastward because of the influencing by solar activity over the tropical western Pacific. Further analysis showed that the evolutionary process of the solar signal in ocean-atmosphere system over the tropical western Pacific was consistent with the analysis of OLR and vertical velocity. By ocean-atmosphere coupling, the solar signal in tropical convection probably was good for triggering a lagged convection dipole mode, and showed a modulation to climate system there.