发表机构
University of Washington; California Institute of Technology; ENS, PSL Université, Ecole Polytechnique, Sorbonne Université, CNRS（华盛顿大学; 加州理工学院; 法国高等师范学院、巴黎文理研究大学、巴黎综合理工学院、索邦大学、法国国家科学研究中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究结合多源卫星观测与生成式深度学习框架，发现次中尺度锋面是海洋能量级联的关键调控因子，其跨尺度能量转移效率更高，对中尺度涡旋季节性有重要影响。
AI 中文摘要
中尺度涡旋对海洋环流至关重要，但几公里尺度的次中尺度运动通过动能级联影响中尺度涡旋能量学的程度仍不确定。高分辨率模拟预测，次中尺度锋面是该级联的关键调控因子，既向下传递能量至耗散，也向上传递能量以维持和塑造中尺度涡旋的季节性。验证这些预测一直很困难，因为现有观测和状态估计无法在足够广阔的区域内解析次中尺度洋流。本文通过将多源卫星观测与生成式深度学习框架结合，绘制了海洋次中尺度能量级联图，该框架利用从模拟中学到的物理上合理的动力学，重建了无间隙、公里尺度的表层洋流。将其应用于多涡旋的阿古拉斯洋流系统，发现次中尺度在10公里以上通过向上能量级联为中尺度提供能量，促成中尺度涡旋的季节性；在10公里以下，次中尺度锋面的辐合驱动向下级联至耗散。向上和向下路径均集中在锋面内，跨尺度转移效率可高出一个数量级。尽管锋面范围有限，却占区域积分级联的很大比例，确立其为级联的关键调控因子及下一代涡旋参数化的目标。
英文摘要
Mesoscale eddies are fundamental to the ocean circulation, yet the extent to which submesoscale motions, a few kilometers across, influence mesoscale eddy energetics through a kinetic energy cascade remains uncertain. High-resolution simulations predict that submesoscale fronts are key regulators of the cascade, transferring energy both downscale towards dissipation and upscale to sustain and shape the seasonality of mesoscale eddies. Testing these predictions has remained difficult because existing observations and state estimates cannot resolve submesoscale currents over sufficiently broad domains. Here we map the ocean's submesoscale energy cascade by combining multi-source satellite observations with a generative deep learning framework, reconstructing gap-free, kilometer-scale surface currents with physically plausible dynamics learned from simulations. Applying this to the eddy-rich Agulhas Current system, we find that submesoscales energize the mesoscale through an upscale energy cascade above 10 km, contributing to the seasonality of mesoscale eddies. Below 10 km, convergence at submesoscale fronts drives a downscale cascade towards dissipation. Both upscale and downscale pathways concentrate within fronts, where cross-scale transfer is up to an order of magnitude more efficient. Despite their limited extent, fronts account for a substantial fraction of the domain-integrated cascade, establishing them as key regulators of the cascade and targets for next-generation eddy parameterizations.
CommentsUnder review at Communications Earth & Environment
