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• 04/03/2025 - Markus HOLZNER: "Transport in environmental fluid dynamics: from turbulent dispersion to soil respiration"

  

  Markus HOLZNER (BOKU University Vienna)

  In this talk, I sketch some recent themes from my research group in environmental fluid dynamics, starting with a brief survey of the main fluid flow problems that we have been investigating in recent years. Then, I discuss in more depth two topics: the dispersion of particle pairs in turbulence and the emission of carbon dioxide from soils via heterotrophic respiration.

  Tuesday, 16:45h - 18:15h

  Location: Room 2F513, (Exner-Raum), Josef-Holaubek-Platz 2, UZA 2, 1090 Vienna and online!
• 11/03/2025 - Efrem MACONI: "The Solar System's passage through the Radcliffe wave during the middle Miocene" Changed time 17:00h!!!

  

  Efrem MACONI (University of Vienna)

  As our Solar System orbits the Milky Way, it encounters Galactic environments with varying interstellar densities. The Gaia mission has revolutionized our understanding of the local stellar neighborhood, revealing coherent gas structures such as the Radcliffe Wave and their motion in space. Our research reveals that the Sun's trajectory intersected this Galactic structure in the Orion star-forming region between 11.5 and 18.2 Myr, with the most likely transit around 14 Myr ago, coinciding with a period of Earth's climate reorganization known as the Middle Miocene transition.

  Paper

  Press release

  Tuesday, new 17:00h - 18:15h

  Location: Room 2F513, (Exner-Raum), Josef-Holaubek-Platz 2, UZA 2, 1090 Vienna and online!
• 18/03/2025 - Andreas DÖRNBRACK: "Transient tropopause waves"

  Andreas DÖRNBRACK (DLR, Deutsches Zentrum für Luft- und Raumfahrt)

  Flight-level airborne observations have often detected gravity waves with horizontal wavelengths λx≲10km near the tropopause. Here, in situ and remote sensing aircraft data of these short gravity waves trapped along tropopause inversion layer and collected during a mountain-wave event over southern Scandinavia are analyzed to quantify their spectral energy and energy fluxes and to identify nonstationary modes. A series of three-dimensional numerical simulations are performed to explain the origin of these transient wave modes and to investigate the parameters on which they depend. It turns out that mountain-wave breaking in the middle atmosphere and the subsequent modification of the stratospheric flow are the key factors for the occurrence of trapped modes with λx≲10km. In particular, the intermittent and periodic breaking of mountain waves in the lower stratosphere forms a wave duct directly above the tropopause, in which the short gravity waves are trapped. The characteristics of the trapped, downstream-propagating waves are mainly controlled by the sharpness of the tropopause inversion layer. It could be demonstrated that different settings for optimizing the numerical solver have a significantly smaller influence on the solutions.

  Tuesday, 16:45h - 18:15h

  Location: Room 2F513, (Exner-Raum), Josef-Holaubek-Platz 2, UZA 2, 1090 Vienna and online!
• 25/03/2025 - Ulrike ROMATSCHKE: "TBA"

  Ulrike ROMATSCHKE (NCAR)

  Abstract will follow.
  

  Tuesday, 16:45h - 18:15h

  Location: Room 2F513, (Exner-Raum), Josef-Holaubek-Platz 2, UZA 2, 1090 Vienna and online!
• 08/04/2025 - Steve SHERWOOD: "Physics, meteorology and impacts of extreme humid heat"

  Steve SHERWOOD (UNSW Climate Change Research Centre)

  Heat stress is now regarded as the most economically costly impact of climate change, and one that could test our limits of adaptation. I will go through the physics of moist heat, how it is limited by atmospheric processes, and how those processes do not always work.

   

  Tuesday, 16:45h - 18:15h

  Location: Room 2F513, (Exner-Raum), Josef-Holaubek-Platz 2, UZA 2, 1090 Vienna and online!
• 06/05/2025 - Takemasa MIYOSHI: "TBA"

  Takemasa MIYOSHI (RIKEN Center for Computational Science)

  Abstract will follow.
  

  Tuesday, 16:45h - 18:15h

  Location: Room 2F513, (Exner-Raum), Josef-Holaubek-Platz 2, UZA 2, 1090 Vienna and online!