- Max Planck Institute for Dnamics and Self-Organization, Fluid Physics, Pattern Formation and Biocomplexity , Göttingen, Germany (eberhard.bodenschatz@ds.mpg.de)
It is impossible to build measurement towers that are several kilometers high. Traditionally, aircraft have been used for atmospheric measurements. Due to their high true air speed, time-resolved measurements from manned aircraft are very challenging. This is especially true for measurements in clouds. Dropsondes and sounding balloons are regularly used to measure atmospheric profiles. However, it is not possible to measure the transport properties of moisture, temperature and aerosols. Unmanned aerial vehicles and drones can be used to measure atmospheric properties. However, due to either the high true air speed or the downwash from the propeller system, measurements of 3D wind speed are quite limited. In addition, the payload of these systems is modest. It is impossible to measure for many hours or days. It would therefore be desirable to have a system that can serve the same purpose as a tower, but can reach heights of several kilometers.
In this talk I will present the Max Planck Cloud Kite Observatory. It is a tethered helikite system operated from a winch on the ground or from a research vessel. The tether holding the helikite is made of very low weight, high or low density pre-stretched polyethylene. The helikite is both a helium balloon and a kite. By this it is not pushed towards the ground at high windspeeds nor does it fall to the ground when the wind stops. By mounting two 250m^3 helikites on top of each other, we achieved a safe lift of 150kg on the tether. Remotely operated instruments can be easily mounted anywhere on the tether. The system is certified for wind speeds up to 25m/s. Due to its stationary location it has shown to supplement measurements with UAVs perfectly. In addition multiple tethered helikite observatories can be employed in close vicinity to each other. In other words, the Max Planck Cloud Kite is a mobile observatory platform with the same utility as a multi kilometer high tower.
I will present the system: winch, helikite, mounting strategies, the helium recovery system and the instruments we have developed to measure eddy covariances, aerosols, and cloud particle dynamics by holographic particle image velocimetry. I will give an outlook on how such a system can be used to highly resolve stratocumulus clouds and other situations.
How to cite: Bodenschatz, E. and Bagheri, G.: Tethered Helikite Observatories, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14053, https://doi.org/10.5194/egusphere-egu25-14053, 2025.
