Turbulence and Diffusion

The impact of micro-scale turbulence on the dynamics can be described in the statistical mean as an effective diffusivity. The statistical behavior of large-scale waves can be described as macro-turbulence. Both concepts need to be considered for a correct treatment of resolved and unresolved scales in numerical simulations.

Methods

For the topic, circulation models with parameterized turbulence were used (KMCM, UA-ICON), partly coupled with a chemistry model (CTM-IAP). Theoretical contributions on this subject were devoted to the problem of wave-induced mixing and turbulent closure at different scales.

• Avsarkisov, V., E. Becker & T. Renkwitz, 2022: Turbulent Parameters in the Middle Atmosphere: Theoretical Estimates Deduced from a Gravity Wave–Resolving General Circulation Model. J. Atmos. Sci. 79,  4: 933-952, doi:10.1175/jas-d-21-0005.1.
• Avsarkisov, V. & J. F. Conte, 2023: The Role of Stratified Turbulence in the Cold Summer Mesopause Region. J. Geophys. Res. Atmos. 128,  19: 038322, doi:10.1029/2022jd038322.
• Gandía-Barberá, S., F. Alcántara-Ávila, S. Hoyas & V. Avsarkisov, 2021: Stratification effect on extreme-scale rolls in plane Couette flows. Phys. Rev. Fluids 6,  3, doi:10.1103/PhysRevFluids.6.034605.
• Ghosh, P., M. He, R. Latteck, T. Renkwitz, V. Avsarkisov, M. Zecha & J. L. Chau, 2022: Characteristics of Frequency-Power Spectra in the Troposphere and Lower Stratosphere Over Andøya (Norway) Revealed by MAARSY. J. Geophys. Res. Atmos. 127,  13, doi:10.1029/2021jd036343.
• Poblet, F. L., J. L. Chau, J. F. Conte, V. Avsarkisov, J. Vierinen & H. Charuvil Asokan, 2022: Horizontal Wavenumber Spectra of Vertical Vorticity and Horizontal Divergence of Mesoscale Dynamics in the Mesosphere and Lower Thermosphere Using Multistatic Specular Meteor Radar Observations. Earth Space Sci. 9,  9: 002201, doi:10.1029/2021ea002201.
• Poblet, F. L., J. Vierinen, V. Avsarkisov, J. F. Conte, H. Charuvil Asokan, C. Jacobi & J. L. Chau, 2023: Horizontal Correlation Functions of Wind Fluctuations in the Mesosphere and Lower Thermosphere. J. Geophys. Res. Atmos. 128,  6, doi:10.1029/2022jd038092.
• Schaefer-Rolffs, U., 2023: A Dynamic Mixed Model for General Circulation Models. Meteorol. Z. 32,  5: 413-429, doi:10.1127/metz/2023/1160.
• Söder, J., C. Zülicke, M. Gerding & F.-J. Lübken, 2021: High-resolution observations of turbulence distributions across tropopause folds. J. Geophys. Res. Atmos. 126,  6: 033857, doi:10.1029/2020JD033857.