Understanding how droplets react
Area of research: hydrodynamics and self-organization Clouds produce rain. Or not, as the case may be. What actually goes on inside a cloud is still not fully understood, undermining the accuracy of both weather forecasts and climate models.
Scientists at the Max Planck Institute for Dynamics and Self-organization in Göttingen (Germany) have been simulating and modelling cloud formation for years in a high-tech laboratory setting. However, in a laboratory it is virtually impossible to simulate the process in which tiny droplets collide in turbulent flow, forming larger droplets and ultimately producing rain. Therefore the team decided to create a laboratory in the clouds. They built an installation at the Schneefernerhaus, Germany’s highest environmental research station. It’s location, near the summit of the Zugspitze (2,962 m / 9,718 ft), is frequently covered in dense clouds. When a cloud passes, four high-speed cameras can be run out along a seven-meter rail track, tracking the movement, relative distance and collisions of up to a thousand individual cloud particles. In this way, small cloud
patches of a few cubic centimeters can be studied in unprecedented detail. However, the researchers are hoping to take their studies one step further. Preparation is underway to fly a high-speed camera up into the clouds, using a hybrid balloon-kite. This would allow them to study (as yet hypothetical) “cloud holes”, regions free of droplets. The research on the Zugspitze will help to refine weather forecasting and climate models. However, the value of the research goes much further. Many other sciences and engineering puzzles stand to benefit from understanding how smaller droplets collide and combine to form larger droplets. Designing better diesel engines, or understanding how planets form? The Zugspitze’s “cloud computing” might just provide the answers…
Prof. Dr. Eberhard Bodenschatz is full Professor of Physics at the University of Göttingen (Germany) and Department Director of Fluid Dynamics, Pattern Formation and Nanobiocomplexity at the Max Planck Institute for Dynamics and Self-Organization. Together with Detlef Lohse he was one of the two founding fathers of the Max Planck – University of Twente Center for Complex Fluid Dynamics.