Currently the temporal soil net, which is measuring soil moisture and soil temperature down to 50cm below ground surface, is removed. The soil net was partly installed in the middle of agricultural used fields, currently wheat is growing there. Since the crop is harvested soon and soil tillage follows, the sensors have to be taken out from the fields. After the farmers field works they will be set up again for the next measuring period.
The very dry conditions in the last week are also visible at this field works. Big drought cracks are present all around and the very dry and hard soil makes it quite a tough job to dig the sensors out.
Last week several doctoral students of the doctoral programme were busy in the HOAL in repairing and maintaining equipment in the research catchment.
Casings of data and power supply cables were checked for damages, which e.g. sometimes can occur by animals and were repaired. Also weathered logger boxes and discharge measuring weirs were smoothed and repainted. It was a relatively little effort to extend the lifetime of all the installations, which are permanent exposed to the influences of weather and environment.
Yesterday Patrick Hogan and Borbala Szeles have been in the field to calibrate the Eddy covariance devices. Borbala will now gradually take over the responsibilty for the weather station installations with the support of Patrick. For the calibration a dew point generator was used. This device is used for providing a stream of gas with a precisely controlled dew point which for example is used for calibrating the H2O channel of gas analyzers.
Currently an infiltrometer measurement campaign is operated by Tommaso Picciafuoco (guest student from University of Perugia, Italy) at the HOAL catchment. With several Double Ring infiltrometer sets and one Csiro infiltrometer device he is determining the saturaded hydraulic conductivity on a grass land field. Later, some other representative spots in the catchment will be investigated.
Some days ago atmospheric scientist Patrick Hogan was in the field, supported by Matthias Oismüller, to maintain some of the weather station devices. The present weather station (which is measuring raindrop distribution) and the mobile eddy covariance systems (evaporation) were checked and prepared for calibration. Since warmer temperatures are on the way to come evaporation and other parameters are again important to be monitored.