The Effect of Barotropic and Baroclinic Tides on Three‐Dimensional Coastal Dispersion
Abstract
The effects of barotropic and baroclinic tides on three‐dimensional (3‐D) coastal dispersion are examined with realistic, 200‐m horizontal resolution simulations of the Central Californian continental shelf during upwelling. Over multiple tidal cycles, the horizontal relative dispersion and vertical dispersion of 3‐D drifters are similar between simulations with no tides and with barotropic tides. In contrast, baroclinic tides, which dissipate across the shelf and induce vertical mixing, result in a factor of 2–3 times larger horizontal and vertical dispersion. The increase in horizontal dispersion with vertical mixing is qualitatively consistent with weak‐mixing shear dispersion. Without shear dispersion, horizontal dispersion of surface‐trapped (2‐D) drifters was similar in all simulations. However, 2‐D drifter trajectory differences relative to no tide simulations are 3–4 times larger with baroclinic tides than barotropic tides alone. These results demonstrate the need to include baroclinic tides and 3‐D tracking for coastal passive tracer dispersion.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 16, 2018
- Source ID
- 10.1029/2018gl079884
Entities
People
- Ata Suanda
- Falk Feddersen
- Matthew S. Spydell
- Nirnimesh Kumar
Organizations
- National Science Foundation
- Office of Naval Research
- Scripps Institution of Oceanography
- University of Otago
- University of Washington