High‐resolution measurements made across a tidal intrusion front

Publisher Website
Google Scholar
Abstract
High spatial resolution current and hydrographic measurements have been made across a tidal intrusion front in the James River estuary, Virginia, during the first few hours of flood. The current measurements were made with a surface‐towed acoustic Doppler current profiler which was used in both profile and side‐scan configurations. The profile data show a 30–50 cm s−1inflow of water from the Chesapeake Bay, a time‐evolving across‐front density gradient, and downward velocity beneath the front of about 15 cm s−1. The side‐scan observations directly measure the across‐front change in current and provide a view of the three‐dimensional character of the frontal interface. The near‐surface horizontal strain rate, a critical parameter for understanding the modulation of surface waves across the front, is estimated to be about 0.04 s−1. UsingPhillips' [1984] theory as a guide, fronts with such large strain rates as these should be discernible in imagery from the ERS 1 C band synthetic aperture radar for wind speeds of ≤4 m s−1.

This publication has 24 references indexed in Scilit: