Winds, Eddies and Flow through Straits

Abstract

A reversal of the mean flow through the Philippines Mindoro Strait occurred in early February 2008. The flow was southward through the strait during late January and northward during most of February. The flow reversal coincided with the period between two intensive observing cruises (IOP08-1 and IOP08-2) sponsored by Office of Naval Research (ONR) as part of the Philippine Straits Experiment (PhilEx). Employing high-resolution models of the ocean and atmosphere along with in situ ocean and air measurements, we detail the regional and local features that influenced this flow reversal. High-resolution air/sea modeling simulations captured the flow reversal and agreed with measured currents from two moorings in the vicinity of Mindoro Strait. A short (24-27 January) easterly monsoon surge and a longer (9-16 February) northerly surge were represented in the model as well as in QuikSCAT and underway wind data taken during IOP08-2. Mesoscale oceanic dipole eddies off Mindoro and Luzon (Pullen et al., 2008) were formed/enhanced and subsequently detached by these wind events. The cyclonic eddy associated with the easterly surge was opportunistically sampled during the IOP08- 1 cruise and the modeled eddy characteristics were verified using in situ shipboard data. The presence of the cyclonic eddy near Mindoro Strait favored a geostrophic flow southward through the strait. This dominant flow was interrupted by a strong and sustained wind-driven (by the northerly surge) flow reversal in early February when the cyclonic eddy was absent. Enhanced upper ocean stratification in winter 2008 due to anomalously high precipitation served to isolate the near-surface circulation in the observations.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2010
Accession Number
ADA535734

Entities

People

  • Arnold L. Gordon
  • Craig Lee
  • James D. Doyle
  • Janet Sprintall
  • Julie Pullen
  • Matthew H. Alford
  • Paul May

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Space

DTIC Thesaurus Topics

  • Archipelagoes
  • Atmospheres
  • Computer Science
  • Fluid Mechanics
  • High Resolution
  • Islands
  • Measurement
  • Military Research
  • Observation
  • Ocean Currents
  • Oceanography
  • Oceans
  • Philippines
  • Physics Laboratories
  • Shipboard
  • Simulations
  • Underwater Acoustics

Fields of Study

  • Environmental science

Readers

  • Atmospheric Science/Meteorology
  • Coastal Oceanography