Relationships between radiation flux and ENSO in the tropical Pacific over the last 170a

Abstract We used synthetic analysis, EOF decomposition, correlation coefficient analysis and causal analysis to investigate relationships between radiation flux and ENSO in the tropical Pacific in recent 170a. Our results indicate that SDLR increased significantly, by c.0.05 W / (M 2 * a), TOLR decreased slightly, by c.0.02 W / (M 2 * a), SDSR did not change significantly, and TISR increased slightly, by c.0.001 W / (M 2 * a). In the tropical western Pacific region, the average state of the tropospheric atmosphere rising and sinking intersecting area shifted eastward by 0.05 ° / a, and El Niño Modoki events increased. In the Middle East Pacific, especially Niño 3.4 with an ocean depth > 700 m, ocean heat content increased significantly, the maximum ILD region moved eastward, upward movement in the intersecting area was abnormally enhanced, the number of westerly wind bursts weakened, and the probability of El Niño Modoki occurrence increased. There was a correlation and causal relationship between marine heat content in zones Niño3 and Niño4, radiation flux, w and u, v anomalies near the intersecting zone. When the time series of the factor was ahead or behind, the lead lag correlation coefficient generally increased. The location of the ILD maximum only affected TOLR, and only SDLR can affect the longitudinal location of the ILD maximum. The longitudinal location of the ILD maximum and H niño3 , H niño3.4 interact as both cause and effect.