Oceanic Physics-based Parameterizations of Internal Wave-driven Mixing

Descripción del proyecto

Descifrar la cascada energética de la mezcla oceánica

El clima de la Tierra se rige por una cinta transportadora mundial de agua, con corrientes a gran escala que transportan calor y nutrientes por todo el planeta. La energía necesaria para mantener este movimiento depende de la mezcla turbulenta a escala milimétrica. Sin embargo, el proceso por el que las enormes fuerzas de la marea se descomponen en diminutos remolinos que dispersan el calor sigue siendo un misterio. Los modelos climáticos actuales suelen basarse en un mosaico empírico de aproximaciones, lo que genera incertidumbre en las previsiones a largo plazo. El equipo del proyecto OPPIWaM, financiado por el CEI, pretende sustituir estas suposiciones por una comprensión del interior del océano basada en la física. Se centra en las ondas internas, que actúan como conducto principal de la energía. El resultado previsto es una hoja de ruta del flujo de energía desde la superficie hasta el abismo.

Objetivo

Oceanic Physics-based Parameterizations of Internal Wave-driven Mixing (OPPIWaM) tackles one of the most pressing open problems in physical oceanography: how energy cascades toward the small scales to fuel turbulent mixing, one of the main drivers of the large-scale overturning circulation with huge impacts on the Earth’s climate. Mixing scales are below the resolution of ocean circulation models, and the current parameterizations are static and empirical, resulting in high uncertainty in model outputs.
Internal waves (IWs) represent the crucial conduit of energy from the large-scale forcings, such as winds or tides, down to the mixing scales. A grand challenge to upgrade the models’ quality is to leverage the physical properties of this IW interscale energy hub to reach a quantitative understanding of mixing based on the ocean’s equations instead of on empirical numbers.
To do so, OPPIWaM sets up an unprecedented multilevel investigation of the physics of IW-driven mixing, with three main objectives: 1. Develop a first-principle solver for the IW interscale dynamics; 2. Develop reduced-model dynamical approximations to provide interpretation as opposed to a black-box package; 3. Constrain the first-principle and reduced-model dynamics with high-resolution field studies and global observational datasets. Finally, OPPIWaM’s findings will integrate into a dynamical first-principle component ready for implementation in the models. The groundbreaking approach to achieve the objectives hinges upon concurring revolutions in theory (wave turbulence recent breakthroughs), (clustering and equation learning) algorithmic efficiency and availability, and (Argo-led) ocean-observation paradigm change.
High stakes for climate and cutting-edge theoretical, numerical and observational challenges make OPPIWaM’s objectives ambitious. Right timing and PI’s key experience and positioning within nonlinear waves and ocean mixing communities make OPPIWaM’s ambitious objectives achievable.