HR: 0800h
AN: OS41B-0538    [Abstracts]
TI: Variability In The Solomon Sea From Altimetric Sea Level Data
AU: * Melet, A
EM: melet@hmg.inp.fr
AF: Laboratoire des Ecoulements Géophysiques et Industriels, ENSHMG, UJF, INPG 1025 rue de la piscine BP53, Grenoble, 38041, France
AU: Gourdeau, L
EM: lionel.gourdeau@noumea.ird.nc
AF: Institut de Recherche pour le Développement, UMR65 BPA5, Noumea, 98848, New Caledonia
AU: Kessler, W
EM: william.s.kessler@noaa.gov
AF: NOAA/PMEL/OCRD, 7600 Sand Point Way NE, Seattle, WA 98115, United States
AU: Verron, J
EM: verron@hmg.inpg.fr
AF: Laboratoire des Ecoulements Géophysiques et Industriels, ENSHMG, UJF, INPG 1025 rue de la piscine BP53, Grenoble, 38041, France
AB: In the southwest tropical Pacific, subtropical waters from the SEC flow in the Solomon Sea, mainly through the western boundary New Guinea Coastal Undercurrent, and join the equatorial western Pacific by three narrow straits. The NGCU transports part of the spiciness anomalies generated in the South East Pacific and subducted in the thermocline. Because the NGCU is a primary source of the EUC, variations of its characteristics are expected to play a role in the equatorial thermocline features and more generally on decadal climate variability. Therefore, the study of the Solomon Sea is a key issue of the SPICE program. In this study, we focus on the variability of the Solomon Sea in term of sea level. The Solomon Sea is semi closed with a complex topography and numerous islands. Thus, the use of classical gridded altimetric products is inadequate. Consequently, this work is based on original along track Topex/Poseidon data. New data processing (CTOH/LEGOS) has been applied to recover proper data and to gain more information on the altimetric signal in this region. A track-by-track specific and customized post processing has been used to finalize the dataset. These new altimetric data have been assessed against tide gauge data. The analysis of the resulting sea level anomalies exhibits the highest variability observed in the tropical Pacific in an area centred near 8°S and expanding from each side of the Solomon Islands, outside of the WBC. Sea level variability presents a wide temporal spectrum, from intraseasonal to interannual ranges with the notable influence of the monsoon and of ENSO. In the Solomon Sea, three frequencies emerge : 60, 365 and 2000 days. The 60-days frequency seems particularly important in the Solomon Sea compared with the surrounding waters and an EOF analysis is used to understand its features. We also depict the signature of the New Guinea Coastal Current (NGCC), the western boundary current flowing north along the eastern coast of Papua New Guinea, which is particularly important for the connection to the equator. In parallel to this study, a hierarchy of high resolution (1/4°, 1/12°) regional models is also being built. The altimetric dataset will be used to perform a realistic simulation of the region circulations through data assimilation.
DE: 4500 OCEANOGRAPHY: PHYSICAL
DE: 4556 Sea level: variations and mean (1222, 1225, 1641)
DE: 4576 Western boundary currents
SC: Ocean Sciences [OS]
MN: 2007 Fall Meeting