Quantifying Uncertainties in the Modelled Estimates of Extreme Precipitation Events at the Upper Thames River Basin

Assessment of climate change impact on hydrology at watershed scale incorporates downscaling of global scale climatic variables into local scale hydrologic variables and computations of risk of hydrologic extremes in future for water resources planning and management. Atmosphere-Ocean General Circulation (AOGCM) models are designed to simulate time series of future climate responses accounting for enthropogenically induced green house gas emissions. The climatological inputs obtained from several AOGCMs suffer the limitations due to incomplete knowledge arising from the inherent physical, chemical processes and the parameterization of the model structure. This study explores the methods available for quantifying uncertainties from the AOGCM outputs by considering fixed weights from different climate model means for the overall data lengths and provides an extensive investigation of the variable weight nonparametric kernel estimator based on the choice of bandwidths for investigating the severity of extreme precipitation events over the next century. The results of this study indicate that the variable width method is better equipped to provide more useful information of the uncertainties associated with different AOGCM scenarios. This study further indicates an increase of probabilities for higher intensities and frequencies of events. The applied methodology is flexible and can be adapted to any uncertainty estimation studies with unknown densities.https://ir.lib.uwo.ca/wrrr/1032/thumbnail.jp

Assessment of Global and Regional Reanalyses Data for Hydro- Climatic Impact Studies in the Upper Thames River Basin

This study evaluates NCEP-NCAR reanalyses hydro-climatic data as an initial check for assessment of climate change studies and hydrologic modeling on the basin scale. Reanalysis data set for daily precipitation, and temperature from the National Centers for Environmental Prediction-National Center for Atmospheric Research (NCEP-NCAR) (a) global (NNGR) and (b) regional (NARR) reanalysis project are used as input into the semi-distributed hydrologic model (HEC-HMS) during the period of 1980-2005. First, the precipitation and temperature data are interpolated to selected stations to check for their trends and similarity in means and variances. Although NARR shows some over-estimated values, mainly in estimating temperature during the summer months, it has been able to capture the trends. NNGR, on the other hand, has produced inferior results in many cases, especially in generating precipitation when compared with the observed values. With its improved atmospheric analytical ability, NARR appears to have performed better than the NNGR, suggesting that with coarse resolution NNGR may not be applied in climate change studies for medium or small watersheds. Next, an extensive analysis is performed for assessing the performance of the reanalysis data generated flows by comparing it with the observed inputs during May-November. The stream flows generated from the NARR dataset show encouraging results for simulating summertime low flows with less variability and error. NNGR dataset, have proven to be less accurate and highly variable. This study suggests that NARR can be adequately used as either an additional source of data or as an alternative to observations in data scarce regions.https://ir.lib.uwo.ca/wrrr/1033/thumbnail.jp

Development of Probability Based Intensity- Duration-Frequency Curves under Climate Change

Hydrologic design of storm sewers, culverts, retention/detention basins and other components of storm water management systems are typically performed based on specified design storms derived from the rainfall intensity-duration-frequency (IDF) estimates and an assumed temporal distribution of rainfall. Use of inappropriate data or design storms could lead to malfunctions of the infrastructure systems: over-estimation may result in costly over-design or under-estimation may be associated with risk and human safety. One of the expected hydroclimatic impacts of climate change for London is the increase in the magnitude and frequency of extreme rainfalls which can have serious impact on the design, operation and maintenance of existing municipal water infrastructure. This study presents a methodology for updating the rainfall IDF curves for the City of London incorporating various uncertainties associated with the assessment of climate change impacts on a local scale. Overall, two objectives have been achieved: first, an extensive investigation of the possible realizations of future climate from 29 scenarios developed from Atmosphere-Ocean Global Climate Models (AOGCM) and scenarios are performed using a downscaling based disaggregation approach. Annual maximum series of rainfall are fitted to Gumbel distribution to develop IDF curves for 1, 2, 6, 12 and 24 hour durations for 2, 5, 10, 25, 50 and 100 years of return periods. Next, the associated uncertainties are estimated using nonparametric kernel estimation approach and the resultant IDF curve is developed based on a probabilistic approach. The results indicate that rainfall patterns in the City of London will most certainly change in future due to climate change. The use of the multi-model approach, rather than a single scenario is encouraged. Inherent uncertainties associated with different AOGCMs are quantified by a kernel based plug-in estimation approach. The resultant scenario indicates approximately 20- 40% changes in different duration rainfalls for all return periods. Use of a probability based intensity-duration-frequency curve is encouraged in order to apply the updated IDF information with higher level of confidence.https://ir.lib.uwo.ca/wrrr/1034/thumbnail.jp

Use of an Integrated System Dynamics Model for Analyzing Behaviour of the Social-economic-climatic System in Policy Development

Climate change remains one of the most critical issues that humans and the natural world face today. Yet while a strong body of scientific research has identified the risks if mitigation and adaptation measures are not taken, there still remains a policy lag. This leads researchers to pose several questions: is there an identified need by the policy domain for more or different science? Is the science that is conducted made policyrelevant? If not, are there tools to better link science to policy? This report will explain the process of science-policy communication related to the development of an integrated system dynamics model of the social-economic-climatic system at the University of Western Ontario under NSERC strategic grant program funding. It will describe the science-policy interface and outline the main challenge to developing science tools for policy, and will then explain how the UWO research team overcame such challenges. Finally, it explains (a) briefly the proposed model and (b) the process of policy scenarios development. The main objective of the research presented in this report is to bring the model closer to policy makers and emphasize how useful this tool is specifically for the Canadian federal government. The science policy communication process has been established through the set of interviews and workshops. Interviews were used (a) to identify the issues of importance to be incorporated in the model development and (b) to formalize a set of policy scenarios that will provide input for policy making. Workshops were used to communicate science to policy developers and discuss the issues of importance for policy development. The research was fundamentally based on a multi-disciplinary approach that assisted in bridging the research domain to the policy domain. Ultimately, the feedback from the interviews and workshops was embedded in the development of the model and its scenarios, and made it possible to transform policy questions into model scenarios. In other words, by linking science and policy domains, the research team was able to produce a science-based and policy-relevant tool. Limitations to the work mainly reflect the current stage of research and model development. As the strategic research continues on the integrated system dynamics model of the social-economic-climatic system, these limitations are likely to be overcome. The other key limitation is in the selection of the government partners. While the current group of partners has provided valuable insight, further research will aim to expand the group of partners across different departments. This will not only reflect a broader range of interests, but will also more accurately represent a systems view of government. Furthermore, a broader range of disciplinary biases will be consulted, including government policymakers who work more intimately with science and policy research.https://ir.lib.uwo.ca/wrrr/1029/thumbnail.jp

Renormalization group scale-setting from the action - a road to modified gravity theories

The renormalization group (RG) corrected gravitational action in Einstein-Hilbert and other truncations is considered. The running scale of the renormalization group is treated as a scalar field at the level of the action and determined in a scale-setting procedure recently introduced by Koch and Ramirez for the Einstein-Hilbert truncation. The scale-setting procedure is elaborated for other truncations of the gravitational action and applied to several phenomenologically interesting cases. It is shown how the logarithmic dependence of the Newton's coupling on the RG scale leads to exponentially suppressed effective cosmological constant and how the scale-setting in particular RG corrected gravitational theories yields the effective $f(R)$ modified gravity theories with negative powers of the Ricci scalar $R$. The scale-setting at the level of the action at the non-gaussian fixed point in Einstein-Hilbert and more general truncations is shown to lead to universal effective action quadratic in Ricci tensor.Comment: v1: 15 pages; v2: shortened to 10 pages, main results unchanged, published in Class. Quant. Gra

Effect of yohimbine on rat prolactin secretion

ABSTRACT It was recently proposed that yohimbine (YO

Classical Coulomb three-body problem in collinear eZe configuration

Classical dynamics of two-electron atom and ions H$^{-}$, He, Li$^{+}$, Be$^{2+}$,... in collinear eZe configuration is investigated. It is revealed that the mass ratio $\xi$ between necleus and electron plays an important role for dynamical behaviour of these systems. With the aid of analytical tool and numeircal computation, it is shown that thanks to large mass ratio $\xi$, classical dynamics of these systems is fully chaotic, probably hyperbolic. Experimental manifestation of this finding is also proposed.Comment: Largely rewritten. 21 pages. All figures are available in http://ace.phys.h.kyoto-u.ac.jp/~sano/3-body/index.htm

Risk assessment of non-native fishes in the Balkans Region using FISK, the invasiveness screening tool for non-native freshwater fishes

A high level of freshwater fish endemism in the Balkans Region emphasizes the need for non-native species risk assessments to inform management and control measures, with pre-screening tools, such as the Fish Invasiveness Screening Kit (FISK) providing a useful first step. Applied to 43 non-native and translocated freshwater fishes in four Balkan countries, FISK reliably discriminated between invasive and non-invasive species, with a calibration threshold value of 9.5 distinguishing between species of medium and high risk sensu lato of becoming invasive. Twelve of the 43 species were assessed by scientists from two or more Balkan countries, and the remaining 31 species by a single assessor. Using the 9.5 threshold, three species were classed as low risk, 10 as medium risk, and 30 as high risk, with the latter category comprised of 26 moderately high risk, three high risk, and one very high risk species. Confidence levels in the assessments were relatively constant for all species, indicating concordance amongst assessors

STRING v10: protein-protein interaction networks, integrated over the tree of life

The many functional partnerships and interactions that occur between proteins are at the core of cellular processing and their systematic characterization helps to provide context in molecular systems biology. However, known and predicted interactions are scattered over multiple resources, and the available data exhibit notable differences in terms of quality and completeness. The STRING database (http://string-db.org) aims to provide a critical assessment and integration of protein-protein interactions, including direct (physical) as well as indirect (functional) associations. The new version 10.0 of STRING covers more than 2000 organisms, which has necessitated novel, scalable algorithms for transferring interaction information between organisms. For this purpose, we have introduced hierarchical and self-consistent orthology annotations for all interacting proteins, grouping the proteins into families at various levels of phylogenetic resolution. Further improvements in version 10.0 include a completely redesigned prediction pipeline for inferring protein-protein associations from co-expression data, an API interface for the R computing environment and improved statistical analysis for enrichment tests in user-provided networks