EGU2020-21191
https://doi.org/10.5194/egusphere-egu2020-21191
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Macroturbulence Response to Vertical Stratification Change Using Linear Response Function of an Idealized Dry Atmosphere

Pak-Wah Chan1, Pedram Hassanzadeh2, and Zhiming Kuang1,3
Pak-Wah Chan et al.
  • 1Department of Earth and Planetary Sciences, Harvard University, United States of America
  • 2Department of Mechanical Engineering, and Department of Earth, Environmental and Planetary Sciences, Rice University, United States of America
  • 3John A. Paulson School of Engineering and Applied Sciences, Harvard University, United States of America

Rossby radius and Rhines scale are two popular scaling arguments for eddy length scale. They have not been tested in a well-controlled experiment with increased vertical stratification and unchanged jet. This is done using the linear response function of an idealized dry atmosphere calculated by Hassanzadeh and Kuang (2016). The resulting change in zonal wind is mostly less than 0.2m/s when temperature near surface is cooled by more than 2K. In such experiment, energy-containing zonal scale decreases, which is against the prediction of Rossby radius but consistent with the prediction of Rhines scale. Eddy kinetic energy decreases for all wavenumbers and latitudes, but eddy momentum flux strengthens locally around zonal wavenumber 8 and 40°S. This local strengthening is associated with a stronger Pearson correlation between u and v.

How to cite: Chan, P.-W., Hassanzadeh, P., and Kuang, Z.: Macroturbulence Response to Vertical Stratification Change Using Linear Response Function of an Idealized Dry Atmosphere, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21191, https://doi.org/10.5194/egusphere-egu2020-21191, 2020

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Presentation version 1 – uploaded on 05 May 2020
  • AC1: Title change, Pak Wah Chan, 05 May 2020

    Welcome! The uploaded 14-page slides focus on eddy length scale. The new title in the slides reflects such change. We find that no single length scale (Rossby radius, Rhines scale, maximum baroclinic growth scale, or Kuo scale) matches well.
    Author will be present in session NP6.3 for text-based chat during 15:00-15:30 (UTC +2) on 8 May (Fri).