SGER: Quantifying Upper Ocean Response to an Ensemble of Surface Wind Field Forcing During a Madden-Julian Oscillation

Northwest Research Associates, Incorporated, Seattle WA

Investigators

Abstract

The PI will study the upper ocean response to surface wind forcing during a Madden-Julian Oscillation. He will use tropical surface wind data for the western Pacific and Indian Oceans to force several integrations of the Community Climate System Model (CCSM) ocean model component. This study is important for near-term improvements of the CCSM because the model is weak in simulating realistic intraseasonal variability in both the atmospheric and coupled atmosphere-ocean modes. In the coupled mode, modeled ocean annual average zonal velocities and temperature distributions in the equatorial western Pacific depart significantly from well-accepted ocean analyses in the region. The PI will examine the hypothesis that these coupled model deficiencies are related, that is, the surface winds associated with the MJO in the active convective regions of the Indian and western Pacific Oceans are not oscillations about a background state, but rather impulse forcings, often of opposite sign (i.e., westerly wind bursts) to the prevailing easterlies on the equator. If successful, this research will improve climate models and their predictions, which is a service to society.