International Journal of Technology Enhancements and Emerging Engineering Research (ISSN 2347-4289)

IJTEEE >> Volume 3 - Issue 9, September 2015 Edition

International Journal of Technology Enhancements and Emerging Engineering Research  
International Journal of Technology Enhancements and Emerging Engineering Research

Website: http://www.ijteee.org

ISSN 2347-4289

Semi-Annual Variability In The Observed And OGCM Simulated Zonal Currents In The Equatorial Indian Ocean

[Full Text]



M. Anil Kumar



Keywords: OGCM model, Monsoon, semi-annual, ADCP, EEIO



ABSTRACT: Analysis of time series of currents measured along the equator at 77E, 83E and 93E locations is presented with an emphasis on the semi-annual variability of zonal currents in the Eastern equatorial Indian Ocean (EEIO) during November 2004 July 2006. The observed currents are compared with the Ocean General Circulation Model (OGCM) simulated currents for the study period. Semi-annual Wave (SAW) harmonic is fitted to the Acoustic Doppler Current Profiler (ADCP) measured currents at each depth (at 8m depth bins) in the upper 200m time series of zonal velocity revealed i) predominant semi-annual equatorial jets in spring (April-May) and fall (September October) with velocity ranging between 120 and 160 cm/s at 77E and 83E and weaker jets at 93E with inter-annual variability, and ii) eastward flowing spring and monsoon Equatorial Undercurrents (EUC) at around 80-100 m depth. The amplitude of the SAW is large (57 cm/s) at 77E and small (13 cm/s) at 93E. The Observed variation of zonal velocity is compared well with the model simulations at 77E and 83E, but deviated at 93E.



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