The Simple Ocean Data Assimilation (SODA) reanalysis (1958–2001) is used to investigate the decadal variability in the equatorial thermocline in the Pacific.Whereas the thermocline depth exhibits weak variation at decadal time scales, the temperature change in the vicinity of the thermocline in the western Pacific is significant and has a vertical scale of;150 m. Based on a modal decomposition ...

A large fraction (35%–50%) of observed La Niña events last two years or longer, in contrast to the great majority ofElNiño events, which last one year. Here, the authors explore the nonlinear processes responsible for the multiyear persistence of La Niña in the Community Climate System Model, version 4 (CCSM4), a coupled climate model that simulates the asymmetric duration of La Niña and El Niñ...

Observations of the interactions of large amplitude internal seiches with the sloping boundary of Lake Simcoe, Canada show a pronounced asymmetry between up- and downwelling. Data were obtained during a 42-day period in late summer with an ADCP and an array of four thermistor chains located in a 5 km line at the depths where the thermocline intersects the shallow slope of the lakebed. The therm...

Lake Analyzer is a numerical code coupled with supporting visualization tools for determining indices of mixing and stratification that are critical to the biogeochemical cycles of lakes and reservoirs. Stability indices, including Lake Number, Wedderburn Number, Schmidt Stability, and thermocline depth are calculated according to established literature definitions and returned to the user in a...

The performance of acoustic modems in the ocean is strongly affected by the ocean environment. A storm can drive up the ambient noise levels, eliminate a thermocline by wind mixing, and whip up violent waves and thereby break up the acoustic mirror formed by the ocean surface. The combined effects of these and other processes on modem performance are not well understood. The authors have been c...

We assessed the performance of state-of-the-art coupled models in reproducing equatorial undercurrent (EUC) Indian Ocean based on outputs Coupled Model Intercomparison Project Phase 6 (CMIP6) and compared with 5 (CMIP5) models. Our results showed that CMIP6 reproduced boreal winter–spring EUC more realistically than CMIP5 models, although both generations underestimated strength observations. T...

The tropical Indian Ocean has experienced a faster warming rate in the west than in the east over the twentieth century. The warming pattern resembles a positive IndianOcean dipole (IOD) that is well captured by climate models from phase 5 of the CoupledModel Intercomparison Project (CMIP5), forced with the two main anthropogenic forcings, long-lived greenhouse gases (GHGs), and aerosols. Howev...

The turnabout and growth mechanisms of the ENSO are diagnostically studied by analyzing the SST budget of the Cane-Zebiak model. The SST change rates, which are directly linked to the phase transition and growth of the ENSO, are attributed to two processes: the anomalous vertical advection of subsurface temperature by the mean upwelling (thermocline feedback), and the zonal advection of the cli...

Interactions between the tropical oceans and atmosphere permit a spectrum of natural modes of oscillation whose properties—period, intensity, spatial structure, and direction of propagation—depend on the background climatic state (i.e., the mean state). This mean state can be described by parameters that include the following: the time-averaged intensity t of the Pacific trade winds, the mean d...