Our programme

Themes

  1. Observing turbulent and convective processes

    We are inviting studies that use observations to inform understanding and representation of turbulence and convection in a variety of atmospheric conditions. This includes descriptions of and results from field campaigns with a focus on turbulence processes and convection; process-based studies based on single or multi-instrument measurements (including satellites and lab-based studies); model evaluation studies; and more. Studies may focus on any region of the world, on turbulence and dynamical processes in and around convective clouds, and may consider the pre-convective environment, cold pools, and the boundary-layer. We particularly invite observational studies that help address the challenges that arise in NWP models run at kilometre and sub-kilometre scales when aiming to represent turbulent and convective processes.

  2. Representing the turbulent grey zone

    The Grey-zone poses significant challenges for modelling turbulent transfer in the atmospheric boundary layer (ABL). The representation of the ABL becomes highly sensitive to choices in sub-grid transport, which in turn directly shapes the resolved flow field. This session invites contributions that explore physical process understanding, modelling challenges and model behaviour at grey zone resolutions. It will focus on recent advances in parametrisation development – novel approaches to modelling turbulent mixing aiming to improve the representation of energy transfer across the grey-zone – and their evaluation.

  3. Representing the convective grey zone

    We welcome studies focussed on developing better representations of moist convection for the grey zone of resolutions, typically 1-5km grid length. Topics could include the design of new representations, comparisons of the behaviours of existing representations, and theoretical and modelling studies of how, when and why assumptions behind fully-parameterized or fully-explict treatments prove inadequate. Studies of the scale dependency of results within the grey zone, and interactions with larger-scale phenomena will also be welcomed.

  4. Interactions between microphysics and turbulence

    Cloud microphysical properties vary across a wide range of scales and interact with turbulent processes through thermodynamic and radiative feedbacks. The choice of microphysics scheme – including its coupling with other parametrization schemes – has significant impacts on the representation of clouds and precipitation and resulting forecasts. This session invites contributions that explore how cloud microphysical processes affect turbulent and dynamical processes – and vice versa – including model sensitivity studies and studies using Lagrangian or “super-drop” approaches.

  5. Role of dynamics representation in representing turbulent processes

    Physics-dynamics coupling aims to understand the interaction of sub-grid processes with the advective dynamics. It thus aims to fill the gap between developing individual dynamics and physics schemes. Examples include: the coupling of moist processes and boundary layers to the large scale and understanding the interplay between dynamics and sub-grid models in large-eddy simulations of turbulence.

  6. Upscale transfer of turbulence-driven uncertainty in predictability

    The predictability theme of the ParaChute Programme aims to quantify how and on what spatial and temporal scales, turbulent processes impact ensemble predictions. A particular focus is the upscale transfer of uncertainty, its sensitivity to the representation of different physical processes within the model, and the use of this information to identify potential improvements to ensemble reliability at different scales . Participants are invited to submit abstracts on the following topics:

    • Ensemble design and how it might change at different scales
    • Upscale transfer of uncertainty
    • Impact of model changes on predictability (including stochastic physics)
    • Ensemble evaluation techniques across scales

  7. Diurnal cycle of deep convection

    This session invites contributions addressing the diurnal cycle of deep convection, the unified representation of shallow and deep convection, the shallow-to-deep transition, and the initiation mechanisms of deep convection. Particular emphasis is placed on advancing the unified parameterization of shallow and deep convection and improving the theoretical and modelling understanding of the processes governing the shallow-to-deep transition. We welcome both oral and poster presentations employing a broad range of methodologies, including idealized theoretical modelling, large-eddy and convection-permitting simulations, machine learning approaches, as well as observational analyses and field campaign data.