Dissipation and Bathymetric Sensitivities in an Unstructured Mesh Global Tidal Model
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- Department of Civil and Environmental Engineering and Earth Sciences University of Notre Dame Notre Dame IN USA
- Environmental Science Division Argonne National Laboratory Lemont IL USA
- NOAA National Ocean Service Office of Coast Survey National Oceanic and Atmospheric Administration Silver Spring MD USA, University Corporation for Atmospheric Research Boulder CO USA
- NOAA National Ocean Service Office of Coast Survey National Oceanic and Atmospheric Administration Silver Spring MD USA
- Coastal and Hydraulics Laboratory Engineer Research and Development Center U.S. Army Corps of Engineers Vicksburg MS USA
Abstract The mechanisms and geographic distribution of global tidal dissipation in barotropic tidal models are examined using a high resolution unstructured mesh finite element model. Mesh resolution varies between 2 and 25 km and is especially focused on inner shelves and steep bathymetric gradients. Tidal response sensitivities to bathymetric changes are examined to put into context response sensitivities to frictional processes. We confirm that the Ronne Ice Shelf dramatically affects Atlantic tides but also find that bathymetry in the Hudson Bay system is a critical control. We follow a sequential frictional parameter optimization process and use TPXO9 data‐assimilated tidal elevations as a reference solution. From simulated velocities and depths, dissipation within the global model is estimated and allows us to pinpoint dissipation at high resolution. Boundary layer dissipation is extremely focused with 1.4% of the ocean accounting for 90% of the total. Internal tide friction is much more distributed with 16.7% of the ocean accounting for 90% of the total. Often highly regional dissipation can impact basin‐scale and even ocean wide tides. Optimized boundary layer friction parameters correlate very well with the physical characteristics of the locality with high friction factors associated with energetic tidal regions, deep ocean island chains, and ice covered areas. Global complex M 2 tide errors are 1.94 cm in deep waters. Total global boundary layer and internal tide dissipation are estimated, respectively, at 1.83 and 1.49 TW. This continues the trend in the literature toward attributing more dissipation to internal tides.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- National Oceanic and Atmospheric Administration (NOAA); National Science Foundation (NSF); USDOE
- Grant/Contract Number:
- AC02-06CH11357; SC0021105
- OSTI ID:
- 1867900
- Journal Information:
- Journal of Geophysical Research. Oceans, Journal Name: Journal of Geophysical Research. Oceans Journal Issue: 5 Vol. 127; ISSN 2169-9275
- Publisher:
- American Geophysical Union (AGU)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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