Global cascade of kinetic energy in the ocean and the atmospheric imprint

Benjamin A Storer; Michele Buzzicotti; Hemant Khatri; Stephen M Griffies; Hussein Aluie

doi:10.1126/sciadv.adi7420

Global cascade of kinetic energy in the ocean and the atmospheric imprint

Sci Adv. 2023 Dec 22;9(51):eadi7420. doi: 10.1126/sciadv.adi7420. Epub 2023 Dec 20.

Authors

Benjamin A Storer¹, Michele Buzzicotti², Hemant Khatri³, Stephen M Griffies^{4

5}, Hussein Aluie^{1

6}

Affiliations

¹ Department of Mechanical Engineering, University of Rochester, Rochester, NY, USA.
² Department of Physics, University of Rome Tor Vergata and INFN, Rome, Italy.
³ Department of Earth, Ocean and Ecological Sciences, University of Liverpool, Liverpool, UK.
⁴ NOAA Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA.
⁵ Atmospheric and Oceanic Sciences Program, Princeton University, Princeton, NJ, USA.
⁶ Laboratory for Laser Energetics, University of Rochester, Rochester, NY, USA.

Abstract

Here, we present an estimate for the ocean's global scale transfer of kinetic energy (KE), across scales from 10 to 40,000 km. Oceanic KE transfer between gyre scales and mesoscales is induced by the atmosphere's Hadley, Ferrel, and polar cells, and the intertropical convergence zone induces an intense downscale KE transfer. Upscale transfer peaks at 300 gigawatts across mesoscales of 120 km in size, roughly one-third the energy input by winds into the oceanic general circulation. Nearly three quarters of this "cascade" occurs south of 15°S and penetrates almost the entire water column. The mesoscale cascade has a self-similar seasonal cycle with characteristic lag time of ≈27 days per octave of length scales; transfer across 50 km peaks in spring, while transfer across 500 km peaks in summer. KE of those mesoscales follows the same cycle but peaks ≈40 days after the peak cascade, suggesting that energy transferred across a scale is primarily deposited at a scale four times larger.