Velocity and Transport from Oceanic Electric Fields: Principles and Practice

Session ID#: 9654

Session Description:
Electric fields in the ocean are generated by the movement of conductive seawater through the earth's magnetic field.  The technique of measuring these electric fields to calculate velocity has a long history in oceanography, and in recent decades has provided high quality velocity measurements from a strong theoretical basis.  In this tutorial, we explain the physical basis behind this approach through well-known examples: cable voltages across the Straits of Florida provide the transport of the Florida Current, a fundamental element for calculating overturning transport at 26N; while voltages from profiling floats provide velocity profiles used to investigate internal waves and vertical shear.  Best practices are presented for obtaining high quality measurements with commercial electromagnetic instruments, including variable deployment configurations, avoiding noise sources, and calculating depth-averaged velocity.
Moderator:  Karen L Casciotti, Stanford University, Earth System Science, Stanford, United States
Primary Presenter:  Zoltan B Szuts, University of Washington, Seattle, WA, United States
Presenters:  James B Girton, University of Washington, Applied Physics Laboratory, Seattle, WA, United States and Thomas Bayes Sanford, Univ Washington, Applied Physics Lab, Seattle, WA, United States
Index Terms:

4594 Instruments and techniques [OCEANOGRAPHY: PHYSICAL]
  • IS - Instrumentation & Sensing Technologies
  • OD - Ocean Observing and Data Management
  • PO - Physical Oceanography/Ocean Circulation