EXCITATION OF INTERMEDIATE-FREQUENCY EQUATORIAL WAVES AT A WESTERN OCEAN BOUNDARY - WITH APPLICATION TO OBSERVATIONS FROM THE INDIAN-OCEAN

A linear, continuously stratified model is used to study the equatorial waves that are generated at the western boundary of the ocean by wind fields oscillating at periods of 30 and 60 days. Solutions are found in ocean basins with a western boundary oriented meridionally or slanted at a 45°angle, like the one in the Indian Ocean. The possible equatorial waves are Kelvin and Yanai waves, and at the 60-day period there are a few Rossby waves. Because Yanai and Rossby waves typically have short wavelengths, they are not directly forced by the wind; however, they can be strongly excited at the western boundary. When the western boundary is slanted, zonal winds also excite antisymmetric equatorial waves, resulting in considerable meridional flow on the equator. -from Authors