Linear Model Equatorial Wave Dynamics: Animations (Keith Rogers)

(1) Introduction

A series of model runs using the linear ocean circulation model of Cane and Patton have been set up to demonstrate the behavior of equatorial wave dynamics. Specifically, the focus is on equatorial Kelvin and Rossby waves, which have been shown to play an important role in El Nino. The rectangular model is configured for an equatorial domain, with artificial boundaries at 30 degrees north and 30 degrees south. The width of the model domain, approximately 16 thousand kilometers, is approximately equal to that of the Pacific Ocean, from Papua New Guineau to Peru.

The model runs differ in the wind forcing used to excite equatorial waves. The first two examples (Climatological winds and Observed Winds) use measured winds from the Pacific Ocean, so that the waves excited by these winds are analogous to the actual waves one would expect to find in the Pacific Ocean.

The remaining runs use artificial wind forcing functions, which have been chosen to highlight specific qualities of the oceanic wave response.

What you see in the animation is dynamic height, which is roughly equivalent to sea surface elevation. The horizontal axis is longitude and the vertical axis is latitude, with the equator running horizontally across the middle of the frame. The color scale is set so that red represents a maximum in sea surface elevation, and blue represents a minimum.

The animations use Benno Blumenthal's Ingrid-interfaced version of Cane and Patton (1984) linear model for the tropical ocean.

(2) Model Runs

Questions? Email:

alexeyk@ldeo.columbia.edu

Linear Model Equatorial Wave Dynamics: Animations (Keith Rogers)

(1) Introduction

(2) Model Runs

Dynamic Height with Realistic Winds

Dynamic Height with Spatially Constant Zonal Winds[taux=-0.5; tauy=0.]

Dynamic Height with Spatially Constant Meridional Winds [taux = 0.; tauy=0.5]

Dynamic Height with banded zonal winds

Dynamic Height with Gaussian zonal wind distribution

Linear Model Animations: Zonal Velocity