Upper ocean variations across the tropical Atlantic are strongly seasonal due to corresponding seasonality in surface forcing and continental runoff. This implies that many features regional upper state or transport anomalies may also be seasonally locked. In boreal summer autumn, remote sensing sea salinity (SSS) observations show presence of eastward propagating concurrent with development fr...

Field experiments show that the poleward velocity of high-altitude weather balloons may, on rare occasions, be much higher than the observed poleward winds, while their eastward velocity is much slower than the observed eastward winds. Considering a simple physical model of horizontal particle’s motion in the atmosphere, which includes a realistic model of the pressure field, it is shown that t...

Data from a subsurface mooring deployed in the western South China Sea shows clear intra-seasonal oscillations (ISO) at the period of 40~70 days. Analysis of remotelysensed sea surface height (SSH) anomalies in the same area indicates that these ISO signals propagate both eastward and westward. Time-longitude diagrams of ISO signals in SSH anomalies and wind-stress curl indicate that the eastwa...

The boreal winter Madden–Julian oscillation (MJO) remains very weak and irregular in the National Center for Atmospheric Research (NCAR) Community Atmosphere Model version 2 (CAM2) as in its direct predecessor, the Community Climate Model version 3 (CCM3). The standard version of CAM2 uses the deep convective scheme of Zhang and McFarlane, as in CCM3, with the closure dependent on convective av...

The effects of the Indonesian Throughflow (ITF) on ENSO dynamics are studied in a coupled climate model by comparing two simulations, one with an open ITF and the other with a closed ITF. Closing the ITF results in an El Niño–like climate state in the Pacific, which is characterized by weakened trade winds, a flatter equatorial thermocline, and weaker equatorial upwelling. A weakened South Equa...

An oceanic general circulation model is used to investigate the annual cycle of the near-surface currents in the eastern equatorial Pacific Ocean; in particular, the causes of the springtime increase of eastward momentum that reverses the westward surface flow and intensifies the Equatorial Undercurrent are examined. A set of process experiments are carried out that isolates effects due to thre...