Surface-Atmosphere Flux measurements
Vertical fluxes of energy and matter between the earth surface and the atmosphere, e.g. of CO2, water vapour and sensible heat, are important to close balances, and drive or validate both soil and atmosphere models. In the Agrosphere, we focus on two approaches to directly quantify these fluxes: The chamber and the eddy covariance technique. The eddy covariance technique always provides net fluxes, spatially averaged over an upwind area at the hectare scale, between the soil-plant continuum and the atmosphere. It does not disturb the ecosystem of interest and its microclimate, but it relies on certain meteorological conditions, requiring careful quality tests and corrections on the derived fluxes. The chamber method, on the other hand, can be applied on a range of smaller spatial scales, and either to ecosystem net fluxes or the soil only. However, it results in a serious disturbance effect to the ecosystem of interest. Therefore, we apply both methods separately or in combination, depending on research question. Our activities in the following projects aim either at a best-practice application of flux measurement methods to provide optimal data to other subprojects, or at the development and improvement of such methods and their data analysis.
- Links between local scale and catchment scale measurements and modeling of gas exchange processes over land surfaces
- Forest site Wüstebach
Dr. Alexander Graf