Winter bistatic radar campaign at Jungfraujoch
In February/March 2022 we successfully carried out the second stage of our bistatic radar measurements at the High Altitude Research Station Jungfraujoch, this time focused on radar observations of fresh winter snow, as well as in-situ snow pit measurements.
Making use of the lessons learned from last year's August campaign, we were able to make preparations for the rougher winter conditions at 3500m altitude, including strong windgusts, as well as windchill temperatures down to -30°C. Due to logistical considerations the secondary radar receiver placed on the terrace of the East Ridge building needed to be able to endure the winter weather without any personnel intervention. We thus took appropriate precautions to ensure that the radar can withstand both extreme wind gusts, as well as very low temperatures.
In order to relate the acquired monostatic and bistatic polarimetric radar observations of the Jungfraufirn area to snow properties, in-situ observations were performed by Philipp Bernhard and Michael Arnold, including several snow pits with depth down to 380cm. This data will allow us to correlate the Ku-band radar data to the snow properties such as density, temperature, and snow grain size. Philipp and Michael also placed calibration targets in order to ensure polarimetric calibration of both radars, which were simultaneously operated by Marcel Stefko and Pol Villalvilla.
The two campaigns provided a dataset containing both monostatic and bistatic, full-polarimetric observations of the snow cover on top of the Aletsch glacier during both the summer and winter seasons, allowing us to evaluate the difference in the Ku-band polarimetric signature of these two diametrally different states of the snow cover. Furthermore, we acquired uninterrupted time series of lengths up to 30 hours, which will allow us to assess the temporal changes of the area's scattering properties over the course of the daily cycle, with temporal resolution of only a few minutes.
We would like to express our thanks to the team members Philipp Bernhard, Michael Arnold, Pol Villalvilla and Marcel Stefko for their vital contributions to the campaign, as well as staff of the external page High Altitude Research Station Jungfraujoch, especially the custodians Daniela Bissig, Erich Furrer, and Christine and Ruedi Käser for their support over the course of the measurements.