An Evaluation of Kolmogorov's −5/3 Power Law Observed Within the Turbulent Airflow Above the Ocean

In 1941, Kolmogorov postulated that the energy distribution of turbulence, across a particular range of eddy sizes cascading to dissipation, could be uniquely described as a universal −5/3 power law. This theory was readily accepted as the basis for conceptualizing the phenomenological characteristi...

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Veröffentlicht in:Geophysical research letters 2019-12, Vol.46 (24), p.14901-14911
Hauptverfasser: Ortiz‐Suslow, David G., Wang, Qing
Format: Artikel
Sprache:eng
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Zusammenfassung:In 1941, Kolmogorov postulated that the energy distribution of turbulence, across a particular range of eddy sizes cascading to dissipation, could be uniquely described as a universal −5/3 power law. This theory was readily accepted as the basis for conceptualizing the phenomenological characteristics of turbulence and remains central to continued experimental and theoretical developments in turbulence study. However, the theory's own validity lacks final certainty. Here we present the first observation‐based evaluation of Kolmogorov's power law within the atmospheric flow above the ocean. Using a unique platform and a novel analytical approach, we found that the expected power law varies systematically with height above the surface and the local environmental state. Our findings suggest that Kolmogorov's idealized value (−5/3) is approximately valid but, under certain conditions, may depend strongly on the unique processes and dynamics near the ocean surface. This discovery should motivate a reevaluation of how Kolmogorov's framework is applied to geophysical turbulence in the vicinity of the air‐sea interface. Plain Language Summary In 1941, a Russian scientist (A. N. Kolmogorov) put forth a relatively straight‐forward solution to the question that had puzzled fluid scientists and keen observers for a long time: how the large scale fluid motions, which have kinetic energy (E), engender the fine‐scale whorls and eddies endemic in almost any sufficiently vigorous fluid? In a nutshell, Kolmogorov's hypotheses to explain this stated that the distribution of E within the fluid follows a fairly simple formula with the universal power −5/3. Since it was proposed, this theory has formed the basis by which we conceptualize and study fluid turbulence. In the atmosphere, this −5/3 power law is used to study the fundamental physics underlying some of our most pressing problems: forecasting storm intensity, climate‐regulating atmosphere‐ocean exchange, and ocean wave growth. Using a unique ocean observing platform and a novel analytical method, we have conducted the first evaluation of Kolmogorov's −5/3 power law within the marine atmosphere. We demonstrate that this classical theory breaks down near the ocean surface, suggesting that ocean waves play a critical role in the atmospheric motion and energy balance. These findings provide tangible evidence that Kolmogorov's theory needs to be re‐evaluated in the context of flow near ocean waves. While our work represents
ISSN:0094-8276
1944-8007
DOI:10.1029/2019GL085083