Winds, Eddies and Flow through Straits
NAVAL RESEARCH LAB MONTEREY CA
Pagination or Media Count:
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 airsea 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 formedenhanced 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.
- Physical and Dynamic Oceanography
- Fluid Mechanics