Turbulent trace gas flux measurements using a novel Eddy Accumulation system
Carbon dioxide (CO2) is an important Greenhouse gas and plays an essential role in the global carbon cycle. While ecosystem scale turbulent flux measurements using the eddy covariance method have evolved as one of the most powerful tools for studying surface-atmosphere trace gas exchange, current technology limits its application to flux measurements of very few selected trace gas species, mainly CO2, with some more recent attempts on e.g. methane and nitrous oxide. Turbulent fluxes of most other trace gases other than CO2 currently remain challenging or impossible using the eddy covariance method.
Eddy Accumulation is an alternative method for turbulent flux measurements, which has potential for measuring a wide range of trace gases. However, the currently most frequently applied version of eddy accumulation, namely Relaxed Eddy Accumulation (REA), due to its indirect nature, has limited capabilities of observing turbulent fluxes of new trace gases. However, an alternative direct version of the eddy accumulation method exists, which is free of some of the limitations of REA. We have implemented this new technique in a prototype of a novel gas sampling system. This direct Eddy Accumulation system is designed to measure CO2, methane and many other trace gases.
The aim of this Master thesis project is to test and operate the new eddy accumulation system in parallel to conventional eddy covariance systems and compare ecosystem level fluxes of carbon dioxide over a forest obtained from both systems.
This Master?s project includes:
- Calibrating the novel gas sampling system in the laboratory
- Measuring carbon dioxide fluxes in the field by eddy accumulation on a high tower in the National Park Forest Hainich
- Analysing turbulent flux observations from the new eddy accumulation system in comparison with conventional eddy covariance flux measurements (those will be provided).
The ideal candidate will have a strong interest and motivation in ecosystem processes, both physical and ecological, as well as in atmospheric measurement techniques. He/she will learn and apply innovative micrometeorological turbulent flux measurement techniques. Interest/knowledge of programming skills (e.g. R) is an advantage. The work of the Master student will be supported by the Bioclimatology group and the developer of the Eddy Accumulation system. The student will have the opportunity to write / contribute to a scientific publication.
At B.Sc. level the student may focus on a subset of the topic.