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Abstract This work serves as an observation‐based exploration into the role of wave‐driven turbulence at the air‐sea interface by measuring Turbulent Kinetic Energy (TKE) dissipation rates above and below the sea surface. Subsurface ocean measurements confirm a TKE dissipation rate enhancement relative to the predicted law‐of‐the‐wall (εobs > εp), which appears to be fully supported by wave breaking highlighting the role of the transport terms in balancing the subsurface TKE budget. Simultaneous measurements of TKE dissipation rates on the atmospheric side capture a deficit relative to the law‐of‐the‐wall (εobs < εp). This deficit is explained in terms of wave‐induced perturbations, with observed convergence to the law‐of‐the‐wall at 14 m above mean sea level. The deficit on the atmospheric side provides an estimate of the energy flux divergence in the wave boundary layer. An exponential function is used to integrate in the vertical and provide novel estimates of the amount of energy going into the wave field. These estimates correlate well with classic spectral input parameterizations and can be used to derive an effective wave‐scale, capturing wind‐wave coupling purely from atmospheric observations intimately tied to wave‐induced perturbations of the air‐flow. These atmospheric and oceanic observations corroborate the commonly assumed input‐dissipation balance for waves at wind speeds in the 8‐14 ms−1range in the presence of developed to young seas. At wind speeds above 14 ms−1under young seas ()observations suggest a deviation from the TKE input‐dissipation balance in the wave field.
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Impact of Atmospheric Compressibility and Stokes Drift on the Vertical Transport of Heat and Constituents by Gravity Waves
Abstract Vertical transport of heat and atmospheric constituents by gravity waves plays a crucial role in shaping the thermal and constituent structure of the middle atmosphere. We show that atmospheric mixing by non‐breaking waves can be described as a diffusion process where the potential temperature (KH) and constituent (KWave) diffusivities depend on the compressibility of the wave fluctuations and the vertical Stokes drift imparted to the atmosphere by the wave spectrum. KHand KWaveare typically much larger than the eddy diffusivity (Kzz), arising from the turbulence generated by breaking waves, and can exceed several hundred m2s−1in regions of strong wave dissipation. We also show that the total diffusion of heat and constituents caused by waves, turbulence, and the thermal motion of molecules, is enhanced in the presence of non‐breaking waves by a factor that is proportional to the variance of the wave‐driven lapse rate fluctuations. Diffusion enhancements of both heat and constituents of 50% or more can be experienced in regions of low atmospheric stability, where the lapse rate fluctuations are large. These important transport effects are not currently included in most global chemistry‐climate models, which typically only consider the eddy diffusion that is induced when the unresolved, but parameterized waves, experience dissipation. We show that the theoretical results compare favorably with observations of the mesopause region at midlatitudes and describe how the theory may be used to more fully account for the unresolved wave transport in global models.
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- PAR ID:
- 10512772
- Editor(s):
- Randel, William
- Publisher / Repository:
- American Geophysical Union
- Date Published:
- Journal Name:
- Journal of Geophysical Research: Atmospheres
- Edition / Version:
- 1
- Volume:
- 129
- Issue:
- 8
- ISSN:
- 2169-897X
- Page Range / eLocation ID:
- 1-22
- Subject(s) / Keyword(s):
- gravity waves, atmospheric dynamics
- Format(s):
- Medium: X Size: 555.6 kbytes Other: pdf/A
- Size(s):
- 555.6 kbytes
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1029/2023JD040436
