HR: 10:35h
AN: OS52B-02    [Abstracts]
TI: Intraseasonal to Interannual Variability in the Tropical Indo-Pacific of Global POP.
AU: * McClean, J L
EM: mcclean@nps.edu
AF: Naval Postgraduate School, Department of Oceanography (OC/Mn), Monterey, CA 93943 United States
AU: Maltrud, M E
EM: maltrud@lanl.gov
AF: Los Alamos National Laboratory, MS B216, Los Alamos, NM 87545 United States
AU: Ivanova, D P
EM: dpivanov@nps.edu
AF: Naval Postgraduate School, Department of Oceanography (OC/Mn), Monterey, CA 93943 United States
AU: Sprintall, J
EM: janet@beqa.ucsd.edu
AF: Scripps Institution of Oceanography, UCSD, San Diego 9500 Gilman Drive, La Jolla, CA 92093 United States
AB: Remote forcing from both the Pacific and Indian Ocean basins, as well as regional monsoon forcing, complicates property flux estimates within the Indonesian seas and causes variability over a range of time scales. Two global configurations of the Parallel Ocean Program (POP), one eddy-permitting (1/3$\deg$, 32-levels) and the other eddy-resolving (1/10$\deg$, 40-levels), both forced with synoptic atmospheric fluxes are used to characterize the variability on scales ranging from intraseasonal to interannual. Mesoscale variability is examined in the tropical Indo-Pacific of the eddy-resolving model (1994-2001), particularly intraseasonal Throughflow eddies to the west of Timor Strait. Extended Empirical Orthogonal Function (EEOF) analyses of the eddy-permitting model (1979-1997) for both biennial (1.9-3.0 years) and narrow-band interannual (3.2-6.3 years) periodicities in the tropical western Pacific reveal that the strongest variability can be identified as off-equatorial Rossby waves. These off-equatorial Rossby waves interact with the North Pacific western boundary to form coastally trapped waves that propagate through the Indonesian Seas (Ombai Strait) and along the northwest Australian coast of Australia, progressively pulling off into the Indian Ocean as free Rossby waves. Cross-spectra analyses confirm that these coastally trapped waves on interannual scales, but not biennial, partially account for the strong low-frequency signal in the southern tropical Indian Ocean off Australia. They also confirm the contribution of coastally-trapped waves excited by Pacific equatorial Rossby at the tip of Irian Jaya that propagate along the Arafura/Timor Strait waveguide as documented in observational studies.
UR: http://www.oc.nps.navy.mil/navypop
DE: 4215 Climate and interannual variability (3309)
DE: 4231 Equatorial oceanography
DE: 4255 Numerical modeling
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting