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Reference electrode drift resulting from the exchange of ions at the solution/reference electrode chamber interface is the number one reason why ion selective electrodes and pH sensors in particular require recalibration, costing companies up to 70% of the total lifetime cost of a pH probe. In this work, a novel and innovative methodology is proposed in which the reference potential is tracked, allowing for in situ recalibration of the sensor without the need for end-user intervention.

A novel technique to produce reasonable worst‐case rainfall scenarios from ensemble forecasts is presented. This type of scenario is relevant for predicting the risk of localized, intense rainfall events with a duration between 15 min and several hours. Such rainfall events can cause surface‐water (pluvial) flooding. Producing useful forecasts of these events at lead times of more than a few hours is challenging due to the precision and accuracy in rainfall intensity, duration and location that is required. The technique described here addresses these challenges by constructing appropriate scenarios using a neighbourhood technique in combination with ensemble forecasting. It is similar to the distance‐dependent depth–duration analysis described in earlier studies, but it introduces an additional post‐processing step based on probability distribution functions of rainfall accumulation near a location of interest. This additional step makes the reasonable worst‐case scenarios less dependent on grid‐scale behaviour, and helps to generate scenarios with a consistent interpretation. The method is used to compare forecasts with a lead time of 6–36 hr to radar data for several case studies that occurred in Yorkshire. These comparisons also introduce new techniques to present maps of the reasonable worst‐case rainfall accumulation at each location.

Precipitation is often organized along coherent lines of low-level convergence, which at longer time and space scales form well-known convergence zones over the world’s oceans. Here, an automated, objective method is used to identify instantaneous low-level convergence lines in reanalysis data and calculate their frequency for the period 1979–2013. Identified convergence lines are combined with precipitation observations to assess the extent to which precipitation around the globe is associated with convergence lines in the lower troposphere. It is shown that a large percentage of precipitation (between 65% and 90%) over the tropical oceans is associated with such convergence lines, with large regional variations of up to 30% throughout the year, especially in the eastern Pacific and Atlantic Oceans. Over land, the annual-mean proportion of precipitation associated with convergence lines ranges between 30% and 60%, and the lowest proportions (less than 15%) associated with convergence lines occur on the eastern flank of the subtropical highs. Overall, much greater precipitation is associated with long coherent lines (greater than 300 km in length) than with shorter fragmented lines (less than 300 km), and the majority of precipitation associated with shorter lines occurs over land. The proportion of precipitation not associated with any convergence line primarily occurs where both precipitation and frequency of convergence lines are low. The high temporal and spatial resolution of the climatology constructed also enables an examination of the diurnal cycle in the relationship between convergence lines and precipitation. Here an example is provided over the tropical Maritime Continent region.

This thesis analyses Germany's commitment to multilateral military operations. Following the research question why Germany participates in some multilateral military operations but not in others, Germany's respective decision-making process regarding troop deployment in the DR Congo in 2006 on one hand and military non-engagement in Libya 2011 on the other hand is traced. By contrasting the concept of strategic culture with a purely rational assessment of the factors of alliance politics, risk-analysis and military feasibility of the operations, the decisiveness of taking into account Germany's strategic culture to explain deployment decisions is stressed. Neither is there a lack of external pressure for German military participation in the case of Libya, nor is the military operation in the DR Congo decisively less risky or militarily more feasible. Rather, Germany's multilateral and anti- militaristic strategic cultural strands affect its decision-making. Next to demanding a thorough justification and legitimization of any military engagement, two red lines for military deployment can be identified. First, Germany refuses to act unilaterally and displays a high reluctance towards military engagement outside the multilateral framework of the UN, NATO or EU. Secondly, Germany rejects to engage in...

Atmospheric fronts are important for the day-to-day variability of weather in the midlatitudes. It is therefore vital to know how their distribution and frequency will change in a projected warmer climate. Here we apply an objective front identification method, based on a thermal front parameter, to 6-hourly data from models participating in Coupled Model Intercomparison Project phase 5. The historical simulations are evaluated against ERA-Interim and found to produce a similar frequency of fronts and with similar front strength. The models show some biases in the location of the front frequency maxima. Future changes are estimated using the high emissions scenario simulations (Representative Concentration Pathway 8.5). Projections show an overall decrease in front frequency in the Northern Hemisphere, with a poleward shift of the maxima of front frequency and a strong decrease at high latitudes where the temperature gradient is decreased. The Southern Hemisphere shows a poleward shift of the frequency maximum, consistent with previous storm track studies.

Tropical cyclones (TCs) can have a major impact on the coastal communities of Australia and Pacific Island countries. Preparedness is one of the key factors to limit TC impacts and the Australian Bureau of Meteorology issues an outlook of TC seasonal activity ahead of TC season for the Australian Region (AR; 5°S to 40°S, 90°E to 160°E) and the South Pacific Ocean (SPO; 5°S to 40°S, 142.5°E to 120°W). This paper investigates the use of support vector regression models and new explanatory variables to improve the accuracy of seasonal TC predictions. Correlation analysis and subsequent cross-validation of the generated models showed that the Dipole Mode Index (DMI) performs well as an explanatory variable for TC prediction in both AR and SPO, Niño4 SST anomalies—in AR and Niño1+2 SST anomalies—in SPO. For both AR and SPO, the developed model which utilised the combination of Niño1+2 SST anomalies, Niño4 SST anomalies, and DMI had the best forecasting performance. The support vector regression models outperform the current models based on linear discriminant analysis approach for both regions, improving the standard deviation of errors in cross-validation from 2.87 to 2.27 for AR and from 4.91 to 3.92 for SPO.

The development of a dynamical model seasonal prediction service for island nations in the tropical South Pacific is described. The forecast model is the Australian Bureau of Meteorology's Predictive Ocean–Atmosphere Model for Australia (POAMA), a dynamical seasonal forecast system. Using a hindcast set for the period 1982–2006, POAMA is shown to provide skillful forecasts of El Niño and La Niña many months in advance and, because the model faithfully simulates the spatial and temporal variability of rainfall associated with displacements of the southern Pacific convergence zone (SPCZ) and ITCZ during La Niña and El Niño, it also provides good predictions of rainfall throughout the tropical Pacific region. The availability of seasonal forecasts from POAMA should be beneficial to Pacific island countries for the production of regional climate outlooks across the region.

Effects caused in ecotoxicity tests by physical factors due to precipitated particles cannot be used for classification in Europe under the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH). For tin (Sn), results from ecotoxicity tests have been observed to be difficult to interpret in regard to exposures of dissolved Sn. Experiments were undertaken with Sn(IV) chloride at 2-2000 µg L-1 in aquatic test media of differing pHs and hardness. A predictive Sn precipitation model was derived using these data and speciation modelling. Previous ecotoxicity tests assessed with the model indicated that organisms were exposed to Sn precipitates. It was therefore not possible to establish the dissolved Sn doses in the tests, invalidating the results for use in risk assessment. Developing an understanding of the speciation and precipitation behaviour of trace elements should be considered a priority before conducting ecotoxicity testing.

Hurricane Claudette developed from a weak vortex in 6 h as deep convection shifted from downshear into the vortex center, despite ambient vertical wind shear exceeding 10 m s−1. Six hours later it weakened to a tropical storm, and 12 h after the hurricane stage a circulation center could not be found at 850 hPa by aircraft reconnaissance. At hurricane strength the vortex contained classic structure seen in intensifying hurricanes, with the exception of 7°–12°C dewpoint depressions in the lower troposphere upshear of the center. These extended from the 100-km radius to immediately adjacent to the eyewall, where equivalent potential temperature gradients reached 6 K km−1. The dry air was not present prior to intensification, suggesting that it was associated with vertical shear–induced subsidence upshear of the developing storm. It is argued that weakening of the vortex was driven by cooling associated with the mixing of dry air into the core, and subsequent evaporation and cold downdrafts. Evidence suggests that this mixing might have been enhanced by eyewall instabilities after the period of rapid deepening. The existence of a fragile, small, but genuinely hurricane-strength vortex at the surface for 6 h presents difficult problems for forecasters. Such a “temporary hurricane” in strongly sheared flow might require a different warning protocol than longer-lasting hurricane vortices in weaker shear.

The position and orientation of the South Pacific Convergence Zone (SPCZ), modulated by the El Nino-Southern Oscillation (ENSO), determine many of the potentially predictable interannual variations in rainfall in the South Pacific region. In this study, the predictability of the SPCZ in austral summer is assessed using two coupled (ocean-atmosphere) global circulation model (CGCM)-based seasonal prediction systems: the Japan Meteorological Agency's Meteorological Research Institute Coupled Ocean-Atmosphere General Circulation Model (JMA/MRI-CGCM) and the Australian Bureau of Meteorology's Predictive Ocean-Atmosphere Model for Australia (POAMA-M24). Forecasts of austral summer rainfall, initialized in November are assessed over the period 1980–2010. The climatology of CGCM precipitation in the SPCZ region compares favorably to rainfall analyses over subsets of years characterizing different phases of ENSO. While the CGCMs display biases in the mean SPCZ latitudes, they reproduce interannual variability in austral summer SPCZ position indices for forecasts out to 4 months, with temporal correlations greater than 0.6. The summer latitude of the western branch of the SPCZ is predictable with correlations of the order of 0.6 for forecasts initialized as early as September, while the correlation for the eastern branch only exceeds 0.6 for forecasts initialized in November. Encouragingly, the models are able to simulate the large displacement of the SPCZ during zonal SPCZ years 1982–1983, 1991–1992, and 1997–1998.

Includes bibliographical references (leaves 45-46).

This study examined relationships between self-efficacy and symptoms of depression and anxiety in a sample of adolescents (n = 83), aged 13 to 17 years of age, who were receiving special education support on the basis of their school-based identification as students with learning disabilities. This study also examined these relationships within two subsets of the sample, those participants who met "traditional" aptitude-achievement learning disability identification criteria and those who could be classified as having reading disabilities. The participants, who were all volunteers, completed measures assessing their academic skills (Wide Range Achievement Test - 3rd Edition and the Gray Silent Reading Tests), their perceptions of self-efficacy (Academic, Reading, Social, and Emotional Self-Efficacy Questionnaires) and social support (Social Support Questionnaire), and their experience of life events (Life Events Questionnaire) and symptoms of depression (Reynolds Adolescent Depression Scale - 2nd Edition) and anxiety (Multidimensional Anxiety Scale for Children). As expected, emotional and social self-efficacy were strong predictors of symptoms of both depression and anxiety. Contrary to expectations, however, neither academic nor reading self-efficacy was a strong predictor of these symptoms. Also contrary to expectations, females did not report higher symptom levels than males, and participants who experienced particular difficulties in the highly salient area of reading did not report higher symptom levels and lower self-efficacy than other participants in the sample. The most depressed and anxious participants were slightly older, perceived themselves to be less efficacious emotionally, were less satisfied with the social support available to them, and reported experiencing more negative life events than participants who reported the lowest levels of depression and anxiety. For these adolescents, who were receiving in-school academic support, social-emotional factors were more strongly associated with their experience of symptomatology than were academic factors. The prevalence of clinically significant symptoms of depression within this sample (6%) was considerably lower than previous estimates for adolescents from the general population and for adolescents with learning disabilities. In contrast, the prevalence of clinically significant symptoms of anxiety (10.8%) and comorbid depression and anxiety (3.6%) was consistent with previous estimates for adolescents from the general population. Implications of these findings and directions for future research are discussed.