Dematteis Giovanni, Le Boyer Arnaud, Pollmann Friederike, Polzin Kurt L, Alford Matthew H, Whalen Caitlin B, Lvov Yuri V
Dipartimento di Fisica, Università degli Studi di Torino, Torino, Italy.
Physical Oceanography Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA.
Nat Commun. 2024 Aug 29;15(1):7468. doi: 10.1038/s41467-024-51503-6.
Across the stable density stratification of the abyssal ocean, deep dense water is slowly propelled upward by sustained, though irregular, turbulent mixing. The resulting mean upwelling determines large-scale oceanic circulation properties like heat and carbon transport. In the ocean interior, this turbulent mixing is caused mainly by breaking internal waves: generated predominantly by winds and tides, these waves interact nonlinearly, transferring energy downscale, and finally become unstable, break and mix the water column. This paradigm, long parameterized heuristically, still lacks full theoretical explanation. Here, we close this gap using wave-wave interaction theory with input from both localized and global observations. We find near-ubiquitous agreement between first-principle predictions and observed mixing patterns in the global ocean interior. Our findings lay the foundations for a wave-driven mixing parameterization for ocean general circulation models that is entirely physics-based, which is key to reliably represent future climate states that could differ substantially from today's.
在深海稳定的密度分层中，深厚的高密度水体通过持续但不规则的湍流混合缓慢向上推进。由此产生的平均上升流决定了诸如热量和碳输送等大规模海洋环流特性。在海洋内部，这种湍流混合主要由内波破碎引起：这些内波主要由风和潮汐产生，它们非线性相互作用，将能量向下传递，最终变得不稳定、破碎并混合水柱。这种长期以来通过启发式参数化的范式仍然缺乏完整的理论解释。在这里，我们利用波 - 波相互作用理论，并结合局部和全球观测数据来填补这一空白。我们发现第一性原理预测与全球海洋内部观测到的混合模式几乎普遍一致。我们的研究结果为海洋环流模型中基于完全物理的波驱动混合参数化奠定了基础，这对于可靠地描绘未来可能与当前有很大差异的气候状态至关重要。
