HR: 1340h
AN: OS13A-1005    [Abstracts]
TI: Measured and Modeled Currents at a Deep Ocean Volcano: Brothers
AU: * Lavelle, J W
EM: j.william.lavelle@noaa.gov
AF: NOAA/Pacific Marine Environmental Laboratory, 7600 Sand Point Way N.E., Seattle, WA 98115, United States
AU: Massoth, G J
EM: gary.massoth@gmail.com
AF: GNS Science, 1 Fairway Drive, Avalon PO Box 30-368, Lower Hutt, 5040, New Zealand
AU: Baker, E T
EM: Edward.Baker@noaa.gov
AF: NOAA/Pacific Marine Environmental Laboratory, 7600 Sand Point Way N.E., Seattle, WA 98115, United States
AU: de Ronde, C E
EM: Cornel.deRonde@gns.cri.nz
AF: GNS Science, 1 Fairway Drive, Avalon PO Box 30-368, Lower Hutt, 5040, New Zealand
AB: Ocean currents to depths of 1600 m at Brothers volcano (34° 52.25' S, 179 ° 04' E) north of New Zealand have been measured and modeled. Three moorings separated laterally by only 10 km and sampling from September 2004 to May 2005 show high energy flows near summit depth (1300 m) with average speeds > 6 cm s^-1 and maximum speeds > 17 cm s^-1. A primitive equation model shows observed flows to be part of a anticyclonic flow toroidaround Brothers' summit with current maxima of approximately 5 cm s^-1. Nearer the sea surface (200-500 m) M₂ tidal currents vary in amplitude by a factor of three, suggesting that internal tides bathe the site. The variation of sub-tidal currents at the shallowest three current meters is mimicked by time series of geostrophic currents based on Aviso sea level anomalies (SLA). Sea level anomaly distributions over the site often show an E-W oriented SLA ridge to the south of Brothers, which causes westward surface flow; less frequently SLA gradients are in the E-W direction, resulting in intermittent meridional flows.
DE: 4255 Numerical modeling (0545, 0560)
DE: 4512 Currents
DE: 4562 Topographic/bathymetric interactions
SC: Ocean Sciences [OS]
MN: 2007 Fall Meeting