This project is a component of a coordinated study called the Tropical Instability Waves Experiment (TIWE). The P.I. will deploy an array of four current measurement moorings, centered at about 4 deg N, 140 deg W. These moorings will be instrumented with Profiling Current Meters (PCM), which cycle through a specified depth range, and are capable of measuring profiles of near-surface currents, as well as temperature and salinity, with a high degree of vertical and temporal resolution. In collaboration with other TIWE components, and existing NOAA current and temperature moorings, the P.I. will attempt to calculate balances of momentum flux, Reynolds heat flux convergence, energy production by barotropic instability, and background current upwelling. Information on background mean currents will also be analyzed in terms of annual variability.