Instrumentation

Instrumentation#

Eddy covariance#

  • Three-dimensional wind: R3–50, Gill Instruments Ltd., UK; mounted at 2.41m height

  • Gas analyzer for CO2 and H2O molar densities: LI-7500 open path infrared gas analyzer (IRGA), LICOR Biosciences, USA; mounted at 2.42m height, inclined (15°)

Fig. 5 Photo of the CH-CHA research site in April 2014. Photo: Lukas Hörtnagl, Grassland Sciences Group, ETH Zurich#

Meteo#

  • Air pressure (PA): PAA-33X, Keller AG, Switzerland

  • Air temperature (TA): HygroClip, Rotronic AG, Switzerland

  • Photosynthetic photon flux density (PPFD): PAR sensor, Kipp & Zonen, The Netherlands

  • Precipitation (PREC): 2005–2016: rain gage, Toss GmbH, Potsdam, Germany; March 2016–2020: rain gage, Lambrecht meteo GmbH, Germany

  • Radiation balance (SW_IN, SW_OUT, LW_IN, LW_OUT): CNR1, Kipp & Zonen, The Netherlands

  • Relative humidity (RH): HygroClip, Rotronic AG, Switzerland

  • Soil temperature (TS): TB107, Markasub AG, Switzerland

  • Soil water content (SWC): ML2x, Delta-T Devices Ltd, United Kingdom

Data loggers#

Data were recorded by data loggers taking one measurement every 10s:

  • 2005 to 2016: CR10X-2 M; 2016 to 2020: CR1000

  • since March 2020: CR1000X, Campbell Scientific, UT, USA

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