H. W. Hofmann

Learn More
Surface waves and their interactions with sediments and benthic organisms are the main hydrodynamic process affecting littoral ecosystems. Here, we present a long-term data set on surface-wave parameters, which was obtained from the analysis of measurements with a pressure sensor. The data set covers a time period of a year and allows for resolving waves(More)
Water-level fluctuations (WLF) of lakes have temporal scales ranging from seconds to hundreds of years. Fluctuations in the lake level generated by an unbalanced water budget resulting from meteorological and hydrological processes, such as precipitation, evaporation and inflow and outflow conditions usually have long temporal scales (days to years) and are(More)
This study investigates the role of surface waves and the associated disturbance of littoral sediments for the release and later distribution of dissolved methane in lakes. Surface wave field, wave-induced currents, acoustic backscatter strength, and the concentration and distribution of dissolved methane were measured simultaneously in Lake Constance,(More)
Bibliografische Information der Deutschen bliothek Die Deutsche bliothek verzeichnet diese Publikation in der Deutschen Nationalbibliografie; detaillierte bibliografische Daten sind im Internet über Alle Rechte vorbehalten. Ohne ausdrückliche Genehmigung des Verlages ist es nicht gestattet, das Buch oder Teile daraus auf fotomechanischem Weg (Fotokopie,(More)
[1] Sediment resuspension in lake littoral zones (nearshore region) is strongly related to the properties of the surface wavefield. The occurrence and characteristics of surface waves, near‐bottom current velocities, and related suspended sediment concentrations and properties were measured simultaneously in Lake Constance over 1 year. Wind and ship waves(More)
Optical (fluorescence) and acoustic in-situ techniques were tested in their ability to measure the spatial and temporal distribution of plankton in freshwater ecosystems with special emphasis on the harmful and buoyant cyanobacterium P. rubescens. Fluorescence was measured with the multi-spectral FluoroProbe (Moldaenke FluoroProbe, MFP) and a Seapoint(More)
Consequences of internal wave motion for phytoplankton and in particular for the distribution and production of the harmful and buoyant cyanobacterium Planktothrix rubescens were investigated based on data from two field campaigns conducted in Lake Ammer during summer 2009 and 2011. In both years, P. rubescens dominated the phytoplankton community and(More)
We determine wind wave properties and estimate the wave exposure along the entire shore of Lake U ¨ berlingen, a subbasin of Lake Constance, using a third generation spectral wave model (SWAN), and compare results to field data on surface waves at three different sites and to predictions from a simple fetch based model (FETCH). Forcing the models with local(More)
We have measured the variation of the spontaneous emission rate with polarization for self-assembled single quantum dots in two-dimensional photonic crystal membranes, and obtained a maximum anisotropy factor of 6 between the decay rates of the two nondegenerate bright states.