Parameterizing Wave‐Driven Vertical Constituent Transport in the Upper Atmosphere

• Main Authors: Chester S. Gardner, Yafang Guo, Alan Z. Liu
• Format: Article
• Language: English
• Published: American Geophysical Union (AGU) 2019-06-01
• Series: Earth and Space Science
• Subjects: wave transport; upper atmosphere; global modeling
• Online Access: https://doi.org/10.1029/2019EA000625

Abstract Dissipating waves contribute to vertical mixing of the atmosphere, alter molecular and eddy diffusion, and induce chemical transport of reactive species. These processes induce strong vertical transport of atmospheric constituents in regions where wave dissipation is significant. The effective wave diffusivity is proportional to the Stokes drift velocity imparted by the spectrum of vertically propagating waves, which is related to the vertical heat and wave energy fluxes. Because the heat flux cannot be derived from wave parameterization schemes employed in most atmospheric models, wave‐driven constituent transport has not been fully incorporated. However, we show in this paper that wave diffusivity can also be expressed in terms of the eddy diffusivity and variances of the temperature and lapse rate fluctuations, quantities that are readily derived from many wave parameterizations. The theory is in good agreement with lidar measurements of heat fluxes in the mesopause region. Total dynamical diffusivity associated with dissipating waves and turbulence can exceed 300 m2/s near the mesopause.