Browsing by Subject "CO2 STORAGE"

Sort by: Order: Results:

Now showing items 1-2 of 2
  • Montagnani, Leonardo; Gruenwald, Thomas; Kowalski, Andrew; Mammarella, Ivan; Merbold, Lutz; Metzger, Stefan; Sedlak, Pavel; Siebicke, Lukas (2018)
    In eddy covariance measureinents, the storage flux represents the variation in time of the dry molar fraction of a given gas in the control volume representative of turbulent flux. Depending on the time scale considered, and on the height above ground of the measurements, it can either be a major component of the overall net ecosystem exchange or nearly negligible. Instrumental configuration and computational procedures must be optimized to measure this change at the time step used for the turbulent flux measurement Three different configurations are suitable within the Integrated Carbon Observation System infrastructure for the storage flux determination: separate sampling, subsequent sampling and mixed sampling. These configurations have their own advantages and disadvantages, and must be carefully selected based on the specific features of the considered station. In this paper, guidelines about number and distribution of vertical and horizontal sampling points are given. Details about suitable instruments, sampling devices, and computational procedures for the quantification of the storage flux of different GHG gases are also provided.
  • Rebmann, Corinna; Aubinet, Marc; Schmid, Hape; Arriga, Nicola; Aurela, Mika; Burba, George; Clement, Robert; De Ligne, Anne; Fratini, Gerardo; Gielen, Bert; Grace, John; Graf, Alexander; Gross, Patrick; Haapanala, Sami; Herbst, Mathias; Hortnagl, Lukas; Ibrom, Andreas; Joly, Lilian; Kljun, Natascha; Kolle, Olaf; Kowalski, Andrew; Lindroth, Anders; Loustau, Denis; Mammarella, Ivan; Mauder, Matthias; Merbold, Lutz; Metzger, Stefan; Molder, Meelis; Montagnani, Leonardo; Papale, Dario; Pavelka, Marian; Peichl, Matthias; Roland, Marilyn; Serrano-Ortiz, Penelope; Siebicke, Lukas; Steinbrecher, Rainer; Tuovinen, Juha-Pekka; Vesala, Timo; Wohlfahrt, Georg; Franz, Daniela (2018)
    The Integrated Carbon Observation System Re-search Infrastructure aims to provide long-term, continuous observations of sources and sinks of greenhouse gases such as carbon dioxide, methane, nitrous oxide, and water vapour. At ICOS ecosystem stations, the principal technique for measurements of ecosystem-atmosphere exchange of GHGs is the eddy-covariance technique. The establishment and setup of an eddy-covariance tower have to be carefully reasoned to ensure high quality flux measurements being representative of the investigated ecosystem and comparable to measurements at other stations. To fulfill the requirements needed for flux determination with the eddy-covariance technique, variations in GHG concentrations have to be measured at high frequency, simultaneously with the wind velocity, in order to fully capture turbulent fluctuations. This requires the use of high-frequency gas analysers and ultrasonic anemometers. In addition, to analyse flux data with respect to environmental conditions but also to enable corrections in the post-processing procedures, it is necessary to measure additional abiotic variables in close vicinity to the flux measurements. Here we describe the standards the ICOS ecosystem station network has adopted for GHG flux measurements with respect to the setup of instrumentation on towers to maximize measurement precision and accuracy while allowing for flexibility in order to observe specific ecosystem features.