A probabilistic approach to quantifying hydrologic thresholds regulating migration of adult Atlantic salmon into spawning streams

Acknowledgment Data to support this study are provided by the Marine Scotland Science Freshwater Laboratory (MSS-FL) and are available for free download on line [Glover and Malcolm, 2015a, 2015b].Peer reviewedPublisher PD

Extreme Weather: Mitigation Enhancement by Better Forecasts or by Better Knowledge on Event Frequencies?

The quality of forecasts can be measured with a wide variety of indices and formulae. All these approaches rely basically on the relation between the numbers of correct forecasts, wrong forecasts, false alarms and rejected cases. In the case of extreme events damage is the major topic. All extreme events by definition are more or less rare events. In many applications the events frequency of an extreme event is selected to be one event per 100 hundred years. Depending on the application other such event frequencies are in use. The mitigation of damage mainly uses rules for the design structures such as buildings. In principle their proper application would allow damage to occur only if a meteorological event oversteps a certain predefined threshold value. In practice the threshold proves to represent more something like a soft shoulder and damage is already observed to be caused by events somewhat smaller than the damage threshold value for the extreme weather case. No matter what its exact definition each threshold value is connected to an event frequency. This event frequency is hard to obtain in particular in the vicinity of the threshold of the extreme event case, because it has to be derived from data scarce by definition, however long the observation time series are. Therefore, these threshold values are subject to a certain inaccuracy. In addition, the low frequencies show some variability with time. Recently, climate changes support the idea that also the occurrence frequency of extreme values will change, increase, in the future. Calculating the forecast quality using the basic data leads to two formulations of the forecast quality, both based on the same principles. The fraction formulation correctly is free from any absolute damage height, it is sufficient to find one reference value. When going to the cumulative formulation the role of the effect of the frequency of occurrence can clearified. The two equations allow to compare the effects of long term changes and inaccuracies of the frequency of occurrence of extreme events with the effects of the improvements of the weather prediction

The essential value of long-term experimental data for hydrology and water management

We would like to thank the European Research Council ERC for funding the VeWa project and most of Tetzlaff's time (project GA 335910 VeWa). No data were used in producing this manuscript.Peer reviewedPublisher PD

Neutron stars from young nearby associations the origin of RXJ1605.3+3249

Many neutron stars (NSs) and runaway stars apparently come from the same regions on the sky. This suggests that they share the same birth places, namely associations and clusters of young massive stars. To identify NS birth places, we attempt to and NS-runaway pairs that could be former companions that were disrupted in a supernova (SN). The remains of recent (<few Myr) nearby (< 150 pc) SNe should still be identifiable by observing the emission of rare radioisotopes such as 26Al and 60Fe that can also be used as additional indicators to confirm a possible SN event. We investigated the origin of the isolated NS RXJ1605.3+3249 and found that it was probably born ~100 pc far from Earth 0.45 Myr ago in the extended Corona-Australis or Octans associations, or in Sco OB4 ~1 kpc 3.5 Myr ago. A SN in Octans is supported by the identification of one to two possible former companions the runaway stars HIP 68228 and HIP 89394, as well as the appearance of a feature in the gamma ray emission from 26Al decay at the predicted SN place. Both, the progenitor masses estimated by comparison with theoretical 26Al yields as well as derived from the life time of the progenitor star, are found to be ~11MSun.Comment: accepted for publication in PASA, special volume Astronomy with Radioactivities; 10 pages, 4 figures, 5 table

Groundwater dynamics at the hillslope – riparian interface in a year with extreme winter rainfall

We would like to thank the European Research Council (ERC, project GA 335910 VeWa) for funding. We also thank Chris Gabrielli for his help with some of the initial deeper boreholes.Peer reviewedPostprin

Assessing runoff generation in riparian wetlands : monitoring groundwater-surface water dynamics at the micro-catchment scale

Acknowledgements: We would like to thank the European Research Council (ERC, project GA 335910 VeWa) for funding.Peer reviewedPostprin

Erzeugung von Sturm-Schadens-Szenarien am Beispiel des Orkans Anatol

Es wird eine Methode zur Generierung von Sturmszenarien vorgestellt. Mit Hilfe des Lokal Modells werden Ensembles von Szenarios zu historischen Zyklonen abgeleitet. Dabei werden die Antriebsdaten für das Modell so verändert, dass stärkere Sturmfelder nerzeugt werden können. Auf Basis einer Schadensfunktion wird der Sturmschaden abgeschätzt. Damit ist es möglich, die Abdeckung mit Sturmfeldern zur Untersuchungdes Sturmrisikos zu erhöhen