Near‐Surface Oceanic Kinetic Energy Distributions From Drifter Observations and Numerical Models
Abstract
The geographical variability, frequency content, and vertical structure of near‐surface oceanic kinetic energy (KE) are important for air‐sea interaction, marine ecosystems, operational oceanography, pollutant tracking, and interpreting remotely sensed velocity measurements. Here, KE in high‐resolution global simulations (HYbrid Coordinate Ocean Model; HYCOM, and Massachusetts Institute of Technology general circulation model; MITgcm), at the sea surface (0 m) and at 15 m, are compared with KE from undrogued and drogued surface drifters, respectively. Global maps and zonal averages are computed for low‐frequency (<0.5 cpd), near‐inertial, diurnal, and semidiurnal bands. Both models exhibit low‐frequency equatorial KE that is low relative to drifter values. HYCOM near‐inertial KE is higher than in MITgcm, and closer to drifter values, probably due to more frequently updated atmospheric forcing. HYCOM semidiurnal KE is lower than in MITgcm, and closer to drifter values, likely due to inclusion of a parameterized topographic internal wave drag. A concurrent tidal harmonic analysis in the diurnal band demonstrates that much of the diurnal flow is nontidal. We compute simple proxies of near‐surface vertical structure—the ratio 0 m KE/(0 m KE + 15 m KE) in model outputs, and the ratio undrogued KE/(undrogued KE + drogued KE) in drifter observations. Over most latitudes and frequency bands, model ratios track the drifter ratios to within error bars. Values of this ratio demonstrate significant vertical structure in all frequency bands except the semidiurnal band. Latitudinal dependence in the ratio is greatest in diurnal and low‐frequency bands.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 01, 2022
- Source ID
- 10.1029/2022jc018551
Entities
People
- Arin D. Nelson
- Aurélien Ponte
- Brian K. Arbic
- Daniel Garcia
- Dimitris Menemenlis
- Edward D Zaron
- Jay F. Shriver
- Jonathan M. Brasch
- Lingxiao Guan
- Maarten C Buijsman
- Matthew H. Alford
- Paige Martin
- Ryan Abernathey
- Shane Elipot
- Xiaolong Yu
Organizations
- Agence Nationale de la Recherche
- California Institute of Technology
- Columbia University
- Division of Ocean Sciences
- IFREMER
- NASA Earth Science
- Office of Naval Research
- Oregon State University
- Sun Yat-sen University
- United States Naval Research Laboratory
- University of California, San Diego
- University of Miami
- University of Michigan
- University of Rhode Island
- University of Southern Mississippi