Mapping Jets and Eddies in an Eastern Boundary Current.
Abstract
A high-resolution upper-ocean survey of a cyclonic meander and an adjacent eddy in the California Current region near 38N, 126W was conducted in summer 1993. Temperature and salinity were measured from a SeaSoar vehicle, and velocity was measured by a shipboard acoustic Doppler current profiler (ADCP). SeaSoar data show a density front at a depth of 70-100 m with strong cyclonic curvature.The geostrophic velocity fields, referenced to the ADCP data at 200 m, show a surface-intensified jet (0.8-1.0 m/s) that follows the density front through a cyclonic meander. Relative vorticities within the jet are large, ranging from -0.4f t +1.Of, where f is the Coriolis parameter. The SeaSoar density and ADCP velocity data, are used to diagnose vertical velocity via the Q-vector form of the quasigeostrophic omega equation. The diagnosed vertical velocity field shows velocities of 30-40 mldc and is characterized by horizontal scales of 20-30 km. Geostrophic streamline analysis indicates that water parcels make vertical excursions of 20-30 m in 2-3 days, resulting in net vertical velocities of 10-15 miday. Water parcels moving along geostrophic streamlines experience maximum vertical velocities in regions of maximum alongstream change in relative vorticity, an indication of potential vorticity conservation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1997
- Accession Number
- ADA328754
Entities
People
- John A. Barth
Organizations
- Oregon State University