Travelling ionospheric disturbance properties deduced from Super Dual Auroral Radar measurements

Based on modeling of the perturbations in power and elevation angle produced by travelling ionospheric disturbances (TIDs), and observed by the Super Dual Auroral Radar Network, procedures for determining the TID properties are suggested. These procedures are shown to produce reasonable agreement with those properties of the TIDs that can be measured from simultaneous ionosonde measurements. The modeling shows that measurements of angle-of-elevation perturbations by SuperDARN allows for better determination of the TID properties than using only the perturbations of power as is commonly done.On sabbatical from Department Electrical Engineering, University of Western Ontario, London, Ontario, Canada     

Beyond Modelling: Linking Models with GIS for Flood Risk Management

Spatially explicit hydrodynamic flood models can play animportant role in natural hazard risk reduction. A key element of these models that make them suitable for riskreduction is the ability to provide time-series inundation information about the onset, duration and passingof a hazard event. Such information can be critical for landuse planning, for mapping evacuation egress routes,and for locating suitable emergency shelters to name only a few risk treatments. This research contends that abarrier to effective risk reduction is providing disaster managers with access to model results in a structured andflexible framework that allows consequences of different hazard scenarios to be assessed and mapped. Toaddress these limitations, a framework has been developed that links a commercial relational databasemanagement system with a GIS-based decision support system. The framework utilises industry standard dataexchange protocols and results in efficient time-series hazard data management. A case study based in Cairns,in far-north coastal Australia is presented to illustrate how the system has been developed. Results show that theframework reduces data volumes significantly, while making pre-run modelled inundation results rapidly accessibleto disaster managers. Of note is the ability of the framework to present results in terms of risk to buildings,roads and other spatial features in urban regions, and to provide answers to relatively complex risk questions.     

Changes in channel size at river confluences with coarse bed material

A field survey of thirty stream junctions from a small watershed, together with data collected by Miller (1958), allowed us to investigate morphometric adjustments occurring at confluences. The model proposed by Roy and Woldenberg (1986) was slightly modified and used as a tool for morphometric analysis. Two parameters are necessary in order to evaluate the rate of change in channel size at a confluence: the area ratio (channel capacity above the confluence: channel capacity below the confluence) and the discharge ratio (discharge of the minor tributary: discharge of the major tributary). Our data show that total channel capacity tends to decline below most confluences. A reduction in cross-sectional area implies an increase in average flow velocity. This interpretation is consistent with Lyell's observations and with results from recent flume experiments (Best and Reid, 1984).     

Magma genesis in a battered Moon: Effects of basin-forming impacts

Magma genesis in the Moon could have been significantly altered by large impacts if they melted solidified residual liquids and late cumulates from the ‘magma ocean’. Calculations of the heat required to melt these materials, under different assumed conditions, are compared to estimates of the total kinetic energy of the Imbrium impact. For a significant amount of these materials to have been melted, they must have been near their solidus temperatures, the impacts must have been very large, and the lunar lithosphere must have been locally heated at depths of 70 to 140 km. Unless the Imbrium impact released at least the maximum estimated kinetic energy, only larger impacts, e.g., the proposed ‘Gargantuan’ impact, could have augmented the intrinsic lunar heat budget enough to locally alter the abundance, timing of eruption, and chemical compositions of lunar magmas. The mechanical and thermal energy generated by such an impact could have been critical in creating (1) the higher concentrations of radioactive elements in the Imbrium/Procellarum area by migration of residual liquids driven by differential lithospheric thickness; and (2) hybrid mare basalts (representing varying proportions of late cumulates and/or residual liquids incorporated into primitive magmas rising from the partially molten lunar interior). Complete compositional spectra of lunar basalts are to be expected, from primitive mare basalts to pure KREEP and to Ti-rich varieties. Comparison of the Gargantuan/Imbrium area with ancient basins in the eastern nearside area suggests that the interplay between the Moon's internal heat engine and the timing of large impacts was a crucial factor in determining the time of tunar volcanism and the chemical composition of the lavas.     

Short-Term Ozone Forecasting with a Network Model System during Summer 1999

Within the framework of the Tropospheric Research Programme (TFS) four working groups in Germany (University of Stuttgart, University of Cologne, Research Center Karlsruhe, German Weather Service) formed a network developing a model system for chemistry transport calculations on different scales. The network was optimized, based on each module and combined for the different interfaces in order to perform daily preoperational ozone forecasts and its precursors at the German Weather Service in summer 1999 (May through September). The setup of the model system, the interfaces and changes of each module are described. The results of the whole preoperational episode are displayed and discussed. Main efforts were done analyzing the model climate statistics and the verification of the predictions with an extensive data base of observations at stations in Germany. The results of this extensive verification demonstrate the relatively good performance of the entire forecast system.     

Holocene paleoenvironmental change inferred from two sediment cores collected in the Tibetan lake Taro Co

Journal of Paleolimnology - The Tibetan Plateau, also known as the “Water Tower of Asia” because of its function as a water storage and supply region, responds dramatically to modern...     

A geomorphologic kinematic‐wave (GKW) model for estimation of floods from small alpine watersheds

A geomorphologic kinematic‐wave (GKW) model was developed for simulation of extreme floods from small alpine catchments. The GKW model couples the kinematic‐wave theory and the geomorphologic representation of the catchment based on the Horton–Strahler ordering scheme. The model was tested on two small alpine catchments in Switzerland, and the agreement between simulated and observed floods was good. Care must however be taken with the computation of slope and roughness parameters. Copyright © 1999 John Wiley & Sons, Ltd.     

Numerical simulation and seismic performance evaluation of buried pipelines rehabilitated with cured‐in‐place‐pipe liner under seismic wave propagation

The cured‐in‐place‐pipe (CIPP) liner technology involves installation of flexible polymeric composite liners coated with thermosetting resin to the inner surfaces of existing buried pipelines. This innovative technology provides an efficient, economic, and environmentally friendly alternative for rehabilitation of structurally compromised underground pipelines without expensive and disruptive excavation. However, the lack of analytical/numerical procedures to quantify the seismic performance of CIPP liner reinforced pipelines remains a barrier to the seismic design and rehabilitation of underground pipelines. This paper first develops an experimentally validated hysteretic model of ductile iron push‐on joints, reinforced with one particular type of CIPP liner under repeated axial loading. A numerical procedure is then proposed to systematically assess the seismic performance and fragility of straight buried pipelines incorporating push‐on joints and subjected to transient ground deformations. The numerical results indicate that CIPP liner‐reinforced pipelines exhibit favorable robust seismic performance with limited joint damage under high‐intensity transient ground deformations. Copyright © 2016 John Wiley & Sons, Ltd.     

Identification of low frequency waves in the vicinity of the terrestrial bow shock

In this paper, methods for the determination of the wave mode for low frequency waves based on observed differences in phase are reviewed. Examples, using measurements made in the terrestrial foreshock and magnetosheath, are used to illustrate the application of these methods. The use of advance methods such as NARMAX modelling or genetic algorithms to identify the plasma wave mode is also discussed.