TurPhyCloud · The role of Turbulence in the Physics of Clouds

Earth’s dominant cloud type per area covered is Stratocumulus. These low-level, shallow, and Earth’s dominant cloud type per area covered is Stratocumulus. These low-level, shallow, and horizontally spread-out clouds cover one-fifth of the Earth’s surface. Changes in cloud cover may amplify rather than mitigate global warming but the magnitude of this is highly uncertain. One of the greatest challenges in climate science is to predict how clouds in general, and stratocumuli in particular, will change in a warming world. TurPhyCloud brings together 4 teams from Experimental and Theoretical Physics and Meteorology to address the full range of processes governing the formation of these clouds across scales, with particular attention to the role of turbulence. The team will (i) deliver high resolution in-situ measurements with unprecedented spatial resolution, from two field campaigns at Utö Atmospheric and Marine Research Station in the Baltic Sea capturing the full complexity of processes in midlatitude stratocumulus from submicrons to kilometres, (ii) derive statistical models for the turbulent processes of the cloud microphysics, not resolved by large-eddy simulations in a way that exceeds current parameterizations, in accuracy and resolution, (iii) will use their superdroplet method to incorporate the statistical models and use this to (iv) develop a new Microphysics Informed Large-Eddy-Simulation (MiLES) model, guided and verified by the results from the campaigns. The tested and verified MiLES will be embedded in weather and climate models. As a result, TurPhyCloud by a combination of unique measurements with realistic simulations of the MiLES model, will develop major advances in our understanding of how cloud-microphysical processes in stratocumulus interact with radiation and turbulence. TurPhyCloud will reduce uncertainties in climate projections and weather predictions through breakthroughs in measuring, modelling, and understanding stratocumulus dynamics.