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• 07/10/2025 - Klaus HASLINGER: "Hydrometeorological extreme events in a changing climate - an Austrian perspective"

  

  Klaus HASLINGER (Geosphere, Vienna)

  The presentation highlights hydrometeorological extremes in Austria in the context of climate change - ranging from droughts and precipitation variability to heavy rainfall and floods. It discusses historical developments, atmospheric drivers, and recent trends, showing how both droughts and extreme rainfall events are changing in intensity and frequency. The goal is to improve understanding of the interactions between natural climate variability and climate change in order to better assess future risks.
• 14/10/2025 - Thomas AUGUST: "Climate, from space to action: Accurate eyes on Earth’s Energy Balance"

  

  Thomas AUGUST (ESA)

  Short abstract
  Our climate is changing and humankind is already taking some actions. But do we yet have the observing and modelling systems to evaluate, at policy timescales, whether climate measures restore Earth’s energy balance?
  Earth Observations are crucial to decision-making. This talk presents ESA satellite mission concepts designed to provide timely feedback on climate policies and to help adjust societies and our course of action in the climate emergency.

  Full abstract
  Our climate is changing. This is now beyond doubt, as evidenced by decades of direct in situ measurements, surface and satellite observations. At the root of this change lies a delicate balance between the incoming solar energy that powers the Earth system and the energy our planet reflects and emits back to space. Since the Industrial Revolution, human activity has upset this balance, primarily by burning fossil fuels. Anthropogenic greenhouse gas emissions continue to trap energy, causing Earth Energy Imbalance (EEI) and increasing ocean and surface temperatures at an unprecedented pace. This, in turn, impacts our climate, upsets the water cycle, and threatens ecosystems.
   
  Scientists model our Earth system and project different climate trajectories, depending on how humanity manages fossil fuel use. To meet the Paris Agreement target of limiting warming to 1.5 °C above pre-industrial levels, global carbon emissions must peak by 2025, fall by 43% by 2030, and reach net-zero by 2050. While the climate direction is clear, uncertainties remain in the magnitude of the changes ahead of us. These uncertainties stem from the complexity of physical processes, the limits of our knowledge and computational tools, and from the limitations of the observations used to inform models.
   
  Space-based observations are crucial to climate models, providing global and process-dedicated measurements to better understand and predict the Earth system. With the current knowledge and observing systems, the effect of today’s climate measures can, however, only be verified in a couple of decades from now. In this seminar, we will introduce two ESA mission concepts aimed at advancing climate science. TRUTHS (Traceable Radiometry Underpinning Terrestrial- and Helio-Studies) was designed as an in-orbit calibration reference, ensuring the accuracy of current and future Earth observation satellites. ECO (Earth Climate Observatory), a candidate Earth Explorer 12 mission, would for the first time directly measure the Earth’s Energy Imbalance and deliver complementary observations to close the Earth’s Radiation Budget. 
   
  Such missions aim to provide timely feedback on the effectiveness of climate policies and to help societies and decision-makers to adjust our course of actions in the climate emergency.

  Further info here: ESA Application
• 21/10/2025 - Günter BLÖSCHL: "Flood Risks in a Changing Climate: Scientific Insights and Adaptive Strategies" Changed Time: 17:30h!!!

  

  Günter BLÖSCHL (WU Wien)

  Flooding is an escalating challenge under climate change, shaped by meteorological, hydrological, and human factors. This lecture examines the scientific drivers, including intense rainfall, atmospheric circulation, soil moisture, and snowmelt, which vary regionally. Human activities such as land use change, infrastructure, and river regulation further influence flood risks. Addressing these complexities requires integrated flood risk management that combines scientific insight with practical measures like retention basins, river restoration, and early warning systems.

  Changed Time: 17:30 h!!!
• 28/10/2025 - Aleš KUCHAR: "Hunga Tonga eruption's indirect impacts on climate"

  

  Aleš KUCHAR (BOKU)

  In January 2022, the Hunga Tonga-Hunga Ha’apai volcano erupted, sending massive amount of water vapor into the atmosphere. This event had a significant impact on stratospheric and lower mesosphere chemical composition. I will provide mainly a modelling perspective of how these changes may have consequently impacted surface climate.

  Further info to Aleš KUCHAR.
• 04/11/2025 - Dana GRUND: "Calibration of High-Resolution Boundary Layer Simulations"

  

  Dana GRUND (ETH Zurich)

  High-resolution (large-eddy) simulations are the tool of choice to resolve and understand turbulent atmospheric processes. They also serve as ground truth to calibrate larger-scale (climate) models. But how to calibrate these ground truth simulations themselves? This talk explores how to use ensemble data assimilation to calibrate a boundary layer simulation to campaign measurements, as opposed to the time-cycling known from numerical weather prediction. A special focus lies on how the calibration is influenced by different numerical schemes.
• 11/11/2025 - Tomislava VUKICEVIC: "Scale separation challenge for convective scale data assimilation in the presence of convection"

  

  Tomislava VUKICEVIC (University of Belgrade)

  This study investigates scale-dependent sensitivity of three-dimensional (3D) state of convection to coincident atmospheric environment within local meso-gamma scale neighborhoods using a 4500-member ensemble of cloud-resolving model simulations. It is shown that variability of the 3D vertical velocity and total condensate at the convective scales is nearly insensitive to variability of the near-neighborhood atmospheric state environment at horizontal scale of about 26 km.

  In contrast, the total condensate at the neighborhood scale and the vertical velocity at the convective scales exhibit notable co-variability with the environment state variables at the convective scales. These findings point to scale separation problems for convective-scale data assimilation and a need for convective-scale specific background uncertainty representation to combat lack of observational constraint of the thermodynamic states at these scales.
• 18/11/2025 - Peter BLOSSEY: "Multiscale convective circulations and extreme precipitation in a global storm resolving model and observations"

  

  Peter BLOSSEY (University of Washington)

  Global storm resolving models (GSRMs) have opened new possibilities for studying many aspects of the tropical atmosphere including extreme precipitation and the coupling of circulations across scales.  In this talk, we study the evolution of large-scale ascent in a stratiform-convective phase space along with its relationship to smaller-scale circulations in one GSRM (the Global System for Atmospheric Modeling or gSAM).  In addition, using radar retrievals of precipitation from the Global Precipitation Measurement Mission (GPM), we construct a database of precipitation features and evaluate the relationship between extreme precipitation, feature size and the localization of precipitation within the features in both GPM and gSAM.
  This presentation is based on joint work with Pedro Angulo-Umaña, Daehyun Kim and Marat Khairoutdinov.
• 02/12/2025 - Annika VOGEL: "Parametric Kalman Filtering: complex flow-dependent forecast uncertainties without ensembles"

  

  Annika VOGEL (University of Cologne)

  This talk introduces a novel approach to estimate complex case-dependent uncertainties in high-dimensional atmospheric systems.
  Instead of sampling forecast uncertainties from an ensemble, this parametric Kalman Filter (PKF) explicitly propagates key parameters of the uncertainty distribution. This enables (1) an understanding of forecast error dynamics and (2) improved data assimilation of sparse observations at low computational costs. After a general introduction to the method, a case-study application to Canadian wildfire smoke dispersal in the operational meteorological-air quality model GEM-MACH is presented.
• 16/12/2025 - Titouan MUZELLEC: "TBA"

  

  Titouan MUZELLEC (University of Vienna)

  Abstract will follow.
• 13/01/2026 - Evelyn McDONALD: "TBA"

  Evelyn McDONALD (University of Vienna)

  Abstract will follow.