Impact of ecosystem metabolism on CO emissions: Insights from high-resolution time series of pH measured in situ.

Lakes and reservoirs are important sources/sinks of atmospheric CO. Primary production and respiration transforming inorganic to organic carbon and vice versa alter CO concentrations in the surface waters and thus affect CO emissions. Here we investigate the link between net-production (NEP) and CO concentrations and emissions at high temporal resolution over more than two months in a German pump storage reservoir.

On the calculation of lake metabolic rates: Diel O and O technique.

Metabolic transformations have a major impact on the development of primary producers in aquatic systems and thus affect the dynamics of the entire aquatic food web. Furthermore, metabolic transformations contribute to the carbon budget and thereby influence CO emissions from aquatic systems. Several techniques have been developed that aim at an easy assessment of metabolic rates over long time periods or in many systems.

Deterministic and Monte Carlo codes for multiple scattering photon transport.

Deterministic and Monte Carlo techniques compete to provide the best description of transport problems. This article presents three examples from our experience in photon transport, which illustrate the close complementarity of these two approaches.

Reconstruction of the X-ray tube spectrum from a scattering measurement.

An inverse technique has been designed to unfold the x-ray tube spectrum from the measurement of the photons scattered by a target interposed in the path of the beam. A special strategy is necessary to circumvent the ill-conditioning of the forward transport algebraic problem. The proposed method is based on the calculation of both, the forward and adjoint analytical solutions of the Boltzmann transport equation.