AMT paper Faber et al. 2023 published

Article

The manuscript "Acquiring high-resolution wind measurements by modifying radiosonde sounding procedures" by Faber et al. has been published on Atmospheric Measurement Techniques.

https://doi.org/10.5194/amt-16-4183-2023

 

Short summary


Weather forecasters around the world use uncrewed balloons to measure wind and temperature for their weather models. In these measurements, wind is recorded from the shift of the balloon by the moving air. However, the balloons and the measurement devices also move by themselves in still air. This creates artificial wind measurements that are normally removed from the data. We show new techniques to avoid these movements and increase the altitude resolution of the wind measurement by 6 times.

Title

Acquiring high-resolution wind measurements by modifying radiosonde sounding procedures

Authors

Faber, J., Gerding, M., and Köpnick, T.

Published

by Atmospheric Measurement Techniques (AMT) at 2023-09-19

Abstract

High-resolution wind measurements are crucial for the understanding of dynamic processes in the atmosphere. In the troposphere and lower stratosphere, radiosondes provide a good vertical resolution of a few metres, but the wind data are usually low-pass filtered by the manufacturer in order to suppress disturbances in the data caused by the spurious motions of the sonde. As an example, the filter within the standard processing of Vaisala radiosondes becomes effective at vertical scales below 300 m for an ascent rate of 5 m s−1.

We describe a method for increasing the usable resolution of radiosonde wind measurements. The main ideas are to avoid self-induced motions of the balloon by keeping it in the subcritical Reynolds number range, to avoid typical pendulum motions of a 15 s period by using a shorter string, and to use data from a descending balloon in order to avoid disturbances from the wake of the balloon affecting temperature and humidity measurements due to the decreased string length. We demonstrate that our changes in hardware and software allow for artefact-free wind data down to scales of 50 m, while the remaining disturbances on even smaller scales are removed. Accordingly, the usable resolution of the wind data has been increased by a factor of 6, compared to the standard data output, at relatively low cost.
 

Citation

Faber, J., Gerding, M., and Köpnick, T.: Acquiring high-resolution wind measurements by modifying radiosonde sounding procedures, Atmos. Meas. Tech., 16, 4183–4193, https://doi.org/10.5194/amt-16-4183-2023, 2023.

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