All Stories

  1. A new parameterisation for homogeneous ice nucleation driven by highly variable dynamical forcings

    Article • December 2024, Copernicus GmbH

    Ulrich Achatz

  2. A Constrained Spectral Approximation of Subgrid‐Scale Orography on Unstructured Grids

    Article • Journal of Advances in Modeling Earth Systems, August 2024, American Geophysical Union (AGU)

    Ulrich Achatz

  3. MS-GWaM: A Three-Dimensional Transient Gravity Wave Parametrization for Atmospheric Models

    Article • Journal of the Atmospheric Sciences, July 2024, American Meteorological Society

    Ulrich Achatz, Dr. Young-Ha Kim

  4. Stratospheric Gravity Waves Impact on Infrasound Transmission Losses Across the International Monitoring System

    Article • Pure and Applied Geophysics, April 2024, Springer Science + Business Media

    Ulrich Achatz, Dr. Young-Ha Kim

  5. Crucial role of obliquely propagating gravity waves in the quasi-biennial oscillation dynamics

    Article • Atmospheric Chemistry and Physics", March 2024, Copernicus GmbH

    Ulrich Achatz, Dr. Young-Ha Kim

  6. The effect of transient lateral internal gravity wave propagation on the resolved atmosphere in ICON/MS-GWaM

    Article • March 2024, Copernicus GmbH

    Ulrich Achatz

  7. Formation and modulation of ice clouds by gravity waves

    Article • March 2024, Copernicus GmbH

    Ulrich Achatz

  8. A constrained spectral approximation of subgrid-scale orography on unstructured grids

    Article • March 2024, Copernicus GmbH

    Ulrich Achatz

  9. Impact of small-scale gravity waves on tracer transport

    Article • March 2024, Copernicus GmbH

    Ulrich Achatz

  10. Interaction of cirrus clouds and gravity waves: towards a coupled representation in coarse resolution model

    Article • March 2024, Copernicus GmbH

    Ulrich Achatz

  11. Validation of an orographic source in a Lagrangian gravity wave parameterization

    Article • March 2024, Copernicus GmbH

    Ulrich Achatz

  12. Atmospheric Gravity Waves: Processes and Parameterization

    Article • Journal of the Atmospheric Sciences, February 2024, American Meteorological Society

    Ulrich Achatz

  13. Crucial role of obliquely propagating gravity waves in the quasi-biennial oscillation dynamics

    Article • November 2023, Copernicus GmbH

    Ulrich Achatz

  14. Theory for the description of the effect of short-wavelength waves in weather and climate models

    Article • Journal of Mathematical Physics, November 2023, American Institute of Physics

    Ulrich Achatz, Dr. Young-Ha Kim

  15. Cirrus cloud formation by gravity waves

    Article • May 2023, Copernicus GmbH

    Ulrich Achatz

  16. MS-GWaM - A three dimensional transient parameterization for internal gravity waves in atmospheric models

    Article • May 2023, Copernicus GmbH

    Ulrich Achatz

  17. Simulation of the quasi-biennial oscillation using a fully 3D transient gravity-wave parameterization

    Article • May 2023, Copernicus GmbH

    Ulrich Achatz

  18. The impact of subgrid-scale gravity waves on the Brewer-Dobson circulation

    Article • May 2023, Copernicus GmbH

    Ulrich Achatz

  19. Towards an implementation of topography in a next-generation gravity-wave parameterisation

    Article • May 2023, Copernicus GmbH

    Ulrich Achatz

  20. Quantifying the impact of gravity waves on infrasound propagation using high-resolution global models for atmospheric specifications

    Article • March 2022, Copernicus GmbH

    Ulrich Achatz

  21. Atmospheric Dynamics

    Article • January 2022, Springer Science + Business Media

    Ulrich Achatz

  22. Towards a transient gravity wave parametrization in atmospheric models

    Article • December 2021, Copernicus GmbH

    Ulrich Achatz

  23. Toward a Numerical Laboratory for Investigations of Gravity Wave–Mean Flow Interactions in the Atmosphere

    Article • Monthly Weather Review, December 2021, American Meteorological Society

    Ulrich Achatz

  24. Interaction Between Stratospheric Kelvin Waves and Gravity Waves in the Easterly QBO Phase

    Article • Geophysical Research Letters, September 2021, American Geophysical Union (AGU)

    Ulrich Achatz, Dr. Young-Ha Kim

  25. Toward Transient Subgrid-Scale Gravity Wave Representation in Atmospheric Models. Part I: Propagation Model Including Nondissipative Wave–Mean-Flow Interactions

    Article • Journal of the Atmospheric Sciences, April 2021, American Meteorological Society

    Ulrich Achatz, Dr. Young-Ha Kim

  26. Toward Transient Subgrid-Scale Gravity Wave Representation in Atmospheric Models. Part II: Wave Intermittency Simulated with Convective Sources

    Article • Journal of the Atmospheric Sciences, April 2021, American Meteorological Society

    Ulrich Achatz, Dr. Young-Ha Kim

  27. A semi-implicit pseudo-incompressible flow solver for diabatic dynamics: Baroclinic-wave life cycles 

    Article • March 2021, Copernicus GmbH

    Ulrich Achatz

  28. Interaction between equatorial stratospheric Kelvin waves and gravity waves in a QBO phase

    Article • March 2021, Copernicus GmbH

    Ulrich Achatz

  29. Reappraising the appropriate calculation of the potential temperature

    Article • March 2021, Copernicus GmbH

    Ulrich Achatz

  30. Numerical investigation of inertia gravity-wave activity in the differentially heated rotating annulus: The impact of boundary conditions

    Article • March 2021, Copernicus GmbH

    Ulrich Achatz

  31. An application of WKBJ theory for triad interactions of internal gravity waves in varying background flows

    Article • Quarterly Journal of the Royal Meteorological Society, January 2021, Wiley

    Ulrich Achatz

  32. Reappraising the appropriate calculation of a common meteorological quantity: potential temperature

    Article • Atmospheric Chemistry and Physics", December 2020, Copernicus GmbH

    Ulrich Achatz

  33. Reappraising the appropriate calculation of a common meteorological quantity: Potential Temperature

    Article • May 2020, Copernicus GmbH

    Ulrich Achatz

  34. A Parametrization for Triad Interactions of Internal Gravity Waves in Varying Background Flows for WKBJ Ray-Tracing Methods

    Article • March 2020, Copernicus GmbH

    Ulrich Achatz

  35. Generation of inertia-gravity waves in idealized baroclinic-wave life cycles: Explicit vs. semi-implicit time stepping in a finite-volume solver for the pseudo-incompressible equations

    Article • March 2020, Copernicus GmbH

    Ulrich Achatz

  36. Intermittency of gravity waves modelled by a transient gravity-wave parametrization coupled with convective sources

    Article • March 2020, Copernicus GmbH

    Ulrich Achatz

  37. Mountain wave parametrization in a transient gravity wave model

    Article • March 2020, Copernicus GmbH

    Ulrich Achatz

  38. Planetary geostrophic Boussinesq dynamics: barotropic flow, baroclinic instability and forced stationary waves

    Article • March 2020, Copernicus GmbH

    Ulrich Achatz

  39. Towards the implementation of a transient gravity wave drag parameterization in atmospheric models

    Article • March 2020, Copernicus GmbH

    Ulrich Achatz

  40. A new laboratory experiment to study gravity waves emission in the atmosphere

    Article • Experiments in Fluids, November 2019, Springer Science + Business Media

    Costanza Rodda, Ulrich Achatz

  41. Planetary geostrophic Boussinesq dynamics: Barotropic flow, baroclinic instability and forced stationary waves

    Article • Quarterly Journal of the Royal Meteorological Society, October 2019, Wiley

    Ulrich Achatz

  42. Efficient Modeling of the Interaction of Mesoscale Gravity Waves with Unbalanced Large-Scale Flows: Pseudomomentum-Flux Convergence versus Direct Approach

    Article • Journal of the Atmospheric Sciences, August 2019, American Meteorological Society

    Ulrich Achatz

  43. Recent progress in modeling imbalance in the atmosphere and ocean

    Article • Physical Review Fluids, January 2019, American Physical Society (APS)

    Ulrich Achatz

  44. Climate Dependence in Empirical Parameters of Subgrid-Scale Parameterizations using the Fluctuation–Dissipation Theorem

    Article • Journal of the Atmospheric Sciences, November 2018, American Meteorological Society

    Martin Pieroth, Ulrich Achatz

  45. Interactions between Mesoscale and Submesoscale Gravity Waves and Their Efficient Representation in Mesoscale-Resolving Models

    Article • Journal of the Atmospheric Sciences, July 2018, American Meteorological Society

    Ulrich Achatz

  46. Stochastic subgrid‐scale parametrization for one‐dimensional shallow‐water dynamics using stochastic mode reduction

    Article • Quarterly Journal of the Royal Meteorological Society, July 2018, Wiley

    Ulrich Achatz

  47. Spontaneous inertia–gravity wave emission in the differentially heated rotating annulus experiment

    Article • Journal of Fluid Mechanics, January 2018, Cambridge University Press

    Steffen Hien, Ulrich Achatz

  48. Finite-amplitude gravity waves in the atmosphere: travelling wave solutions

    Article • Journal of Fluid Mechanics, August 2017, Cambridge University Press

    Mark Schlutow, Ulrich Achatz

  49. Stochastic Parameterization: Toward a New View of Weather and Climate Models

    Article • Bulletin of the American Meteorological Society, March 2017, American Meteorological Society

    Antje Weisheimer, Ulrich Achatz

  50. The interaction between synoptic‐scale balanced flow and a finite‐amplitude mesoscale wave field throughout all atmospheric layers: weak and moderately strong stratification

    Article • Quarterly Journal of the Royal Meteorological Society, December 2016, Wiley

    Ulrich Achatz

  51. The Interaction between Atmospheric Gravity Waves and Large-Scale Flows: An Efficient Description beyond the Nonacceleration Paradigm

    Article • Journal of the Atmospheric Sciences, December 2016, American Meteorological Society

    Ulrich Achatz

  52. Parameterization of stochastic multiscale triads

    Article • Nonlinear Processes in Geophysics, November 2016, Copernicus GmbH

    Ulrich Achatz

  53. The interaction between gravity waves and solar tides in a linear tidal model with a 4‐D ray‐tracing gravity‐wave parameterization

    Article • Journal of Geophysical Research Space Physics, September 2016, American Geophysical Union (AGU)

    Ulrich Achatz

  54. Parametrization of stochastic multiscale triads

    Article • June 2016, Copernicus GmbH

    Ulrich Achatz

  55. Erratum

    Article • Quarterly Journal of the Royal Meteorological Society, October 2015, Wiley

    Stefan Hickel, Ulrich Achatz

  56. Validation of Large-Eddy Simulation Methods for Gravity Wave Breaking

    Article • Journal of the Atmospheric Sciences, September 2015, American Meteorological Society

    Stefan Hickel, Ulrich Achatz

  57. The interaction between gravity waves and solar tides: Results from 4‐D ray tracing coupled to a linear tidal model

    Article • Journal of Geophysical Research Space Physics, August 2015, American Geophysical Union (AGU)

    Ulrich Achatz

  58. Finite-volume models with implicit subgrid-scale parameterization for the differentially heated rotating annulus

    Article • Meteorologische Zeitschrift, January 2015, Schweizerbart

    Stefan Hickel, Ulrich Achatz

  59. Benchmarking in a rotating annulus: a comparative experimental and numerical study of baroclinic wave dynamics

    Article • Meteorologische Zeitschrift, January 2015, Schweizerbart

    Stefan Hickel, Ulrich Achatz

  60. Direct Numerical Simulation of Breaking Atmospheric Gravity Waves

    Article • December 2014, Springer Science + Business Media

    Stefan Hickel, Ulrich Achatz

  61. On the construction of a direct numerical simulation of a breaking inertia-gravity wave in the upper mesosphere

    Article • Journal of Geophysical Research Atmospheres, October 2014, American Geophysical Union (AGU)

    Dr Stefan Hickel, Stefan Hickel, Ulrich Achatz

  62. Gravity wave emission in an atmosphere-like configuration of the differentially heated rotating annulus experiment

    Article • Journal of Fluid Mechanics, October 2014, Cambridge University Press

    Ulrich Achatz

  63. On the application of Wentzel–Kramer–Brillouin theory for the simulation of the weakly nonlinear dynamics of gravity waves

    Article • Quarterly Journal of the Royal Meteorological Society, June 2014, Wiley

    Dr Stefan Hickel, Stefan Hickel, Ulrich Achatz

  64. Range of validity of an extended WKB theory for atmospheric gravity waves: one-dimensional and two-dimensional case

    Article • Journal of Fluid Mechanics, July 2013, Cambridge University Press

    Ulrich Achatz

  65. Fluctuation–Dissipation Supplemented by Nonlinearity: A Climate-Dependent Subgrid-Scale Parameterization in Low-Order Climate Models

    Article • Journal of the Atmospheric Sciences, May 2013, American Meteorological Society

    Ulrich Achatz

  66. A Conservative Integration of the Pseudo-Incompressible Equations with Implicit Turbulence Parameterization

    Article • Monthly Weather Review, March 2013, American Meteorological Society

    Dr Stefan Hickel, Stefan Hickel, Ulrich Achatz

  67. Subgrid-scale closure for the inviscid Burgers-Hopf equation

    Article • Communications in Mathematical Sciences, January 2013, International Press of Boston

    Ulrich Achatz

  68. Stochastic closure for local averages in the finite-difference discretization of the forced Burgers equation

    Article • Theoretical and Computational Fluid Dynamics, May 2012, Springer Science + Business Media

    Ulrich Achatz

  69. Secondary Instabilities in Breaking Inertia–Gravity Waves

    Article • Journal of the Atmospheric Sciences, January 2012, American Meteorological Society

    Ulrich Achatz

  70. On the impact of middle-atmosphere thermal tides on the propagation and dissipation of gravity waves

    Article • Journal of Geophysical Research Atmospheres, December 2011, American Geophysical Union (AGU)

    Ulrich Achatz

  71. Regime of Validity of Soundproof Atmospheric Flow Models

    Article • Journal of the Atmospheric Sciences, October 2010, American Meteorological Society

    Ulrich Achatz

  72. Gravity waves, scale asymptotics and the pseudo-incompressible equations

    Article • Journal of Fluid Mechanics, September 2010, Cambridge University Press

    Ulrich Achatz

  73. Mechanisms controlling the diurnal solar tide: Analysis using a GCM and a linear model

    Article • Journal of Geophysical Research Atmospheres, August 2008, American Geophysical Union (AGU)

    Ulrich Achatz

  74. Modal and Nonmodal Perturbations of Monochromatic High-Frequency Gravity Waves: Primary Nonlinear Dynamics

    Article • Journal of the Atmospheric Sciences, June 2007, American Meteorological Society

    Ulrich Achatz

  75. Gravity-wave breaking: Linear and primary nonlinear dynamics

    Article • Advances in Space Research, January 2007, Elsevier

    Ulrich Achatz

  76. The Primary Nonlinear Dynamics of Modal and Nonmodal Perturbations of Monochromatic Inertia–Gravity Waves

    Article • Journal of the Atmospheric Sciences, January 2007, American Meteorological Society

    Ulrich Achatz

  77. Optimal Growth in Inertia–Gravity Wave Packets: Energetics, Long-Term Development, and Three-Dimensional Structure

    Article • Journal of the Atmospheric Sciences, February 2006, American Meteorological Society

    Ulrich Achatz

  78. Shear and Static Instability of Inertia–Gravity Wave Packets: Short-Term Modal and Nonmodal Growth

    Article • Journal of the Atmospheric Sciences, February 2006, American Meteorological Society

    Ulrich Achatz

  79. On the role of optimal perturbations in the instability of monochromatic gravity waves

    Article • Physics of Fluids, September 2005, American Institute of Physics

    Ulrich Achatz

  80. The dependence of the nonmigrating diurnal tide in the mesosphere and lower thermosphere on stationary planetary waves

    Article • Journal of Atmospheric and Solar-Terrestrial Physics, April 2004, Elsevier

    Ulrich Achatz

  81. Primitive-Equation-Based Low-Order Models with Seasonal Cycle. Part I: Model Construction

    Article • Journal of the Atmospheric Sciences, February 2003, American Meteorological Society

    Ulrich Achatz

  82. Primitive-Equation-Based Low-Order Models with Seasonal Cycle. Part II: Application to Complexity and Nonlinearity of Large-Scale Atmosphere Dynamics

    Article • Journal of the Atmospheric Sciences, February 2003, American Meteorological Society

    Ulrich Achatz

  83. A Two-Layer Model with Empirical Linear Corrections and Reduced Order for Studies of Internal Climate Variability

    Article • Journal of the Atmospheric Sciences, September 1999, American Meteorological Society

    Ulrich Achatz

  84. On the Closure Problem in the Reduction of Complex Atmospheric Models by PIPs and EOFs: A Comparison for the Case of a Two-Layer Model with Zonally Symmetric Forcing

    Article • Journal of the Atmospheric Sciences, October 1997, American Meteorological Society

    Ulrich Achatz

  85. Principal Interaction Patterns in Baroclinic Wave Life Cycles

    Article • Journal of the Atmospheric Sciences, September 1995, American Meteorological Society

    Ulrich Achatz

  86. Cosmic-ray particle transport in weakly turbulent plasmas. Part 2. Mean free path of cosmic-ray protons

    Article • Journal of Plasma Physics, August 1993, Cambridge University Press

    Ulrich Achatz

  87. Interplanetary transport of solar electrons and protons: Effect of dissipative processes in the magnetic field power spectrum

    Article • Journal of Geophysical Research Atmospheres, August 1993, American Geophysical Union (AGU)

    Ulrich Achatz

  88. Cosmic-ray particle transport in weakly turbulent plasmas. Part 1. Theory

    Article • Journal of Plasma Physics, February 1993, Cambridge University Press

    Ulrich Achatz