Equatorial currents at semi-annual period in the Indian Ocean

Journal Article · Sat May 01 04:00:00 EDT 1982 · J. Phys. Oceanogr.; (United States)

DOI:https://doi.org/10.1175/1520-0485(1982)012<0406:ECASAP>2.0.CO;2· OSTI ID:5081298

Luyten, J R; Roemmich, D H

Moored records of zonal velocity in the western equatorial Indian Ocean are dominated by motion of semi-annual period. The motion is coherent over an array spanning more than 1000 Km along the equator, 160 km across the equator, and 500 m in the vertical. The signal has an amplitude of 0.15 m s/sup -1/. It has zonal, vertical and meridional length scales which are long compared to the dimensions of the array, and it shows upward propagation of phase. Behavior is characteristic of an eastward propagating equatorial Kelvin wave and a westward long equatorial Rossby wave. The vertical wavelength is an estimated 5000 m, implying an equatorial trapping scale of 400 km. Zonal wavelengths are approx.8000 km for the equatorial Rossby wave and 24 000 km for the equatorial Kelvin wave. A downward energy flux, estimated to be 3 x 10/sup 16/ erg s/sup -1/, most likely represents propagation away from surface forcing by the zonal wind.

• Research Organization: Woods Hole Oceanographic Institute, Woods Hole, Ma 02543
• OSTI ID: 5081298
• Journal Information: J. Phys. Oceanogr.; (United States), Journal Name: J. Phys. Oceanogr.; (United States) Vol. 12:5; ISSN JPYOB
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580500* -- Oceanography-- (1980-1989)
CURRENTS
DATA ANALYSIS
INDIAN OCEAN
SEAS
SEASONAL VARIATIONS
SURFACE WATERS
TROPICAL REGIONS
VARIATIONS
WATER CURRENTS