Potential Applications of Thermal Fisheye Imagery in Urban Environments

The sky-view factor is a commonly used parameter in urban climatology; but to date, no completely satisfactory technique has yet been developed for its calculation. This letter investigates the potential of a prototype thermal fisheye camera, originally developed for use in the CLOUDMAP2 project, to produce fisheye imagery suitable for sky-view factor analysis. The camera distinguishes between the fraction of cold-space background and warm obstructions (e.g., buildings, trees, and cloud) from which the sky-view factor can be calculated. Early results are promising with excellent segmentation results obtained under clear skies, although the techniques are currently less reliable when clouds are visible in the field of view. However, this is demonstrated to be an advantage as the camera can also be used to simultaneously measure other parameters such as solar-tracks and "local" cloud fractions. The preliminary results indicate potential for the use of the camera for modeling studies in urban environments     

The short term climatic sensitivity of carbonate and silicate weathering fluxes: Insight from seasonal variations in river chemistry

Large seasonal variations in the dissolved load of the headwater tributaries of the Marsyandi river (Nepal Himalaya) for major cations and ⁸⁷Sr/⁸⁶Sr ratios are interpreted to result from a greater dissolution of carbonate relative to silicate at high runoff. There is up to a 0.003 decrease in strontium isotope ratios and a factor of 3 reduction in the Si(OH)₄/Ca ratio during the monsoon. These variations, in small rivers sampling uniform lithologies, result from a different response of carbonate and silicate mineral dissolution to climatic forcing. Similar trends are observed in compiled literature data, from both Indian and Nepalese Himalayan rivers. Carbonate weathering is more sensitive to monsoonal runoff because of its faster dissolution kinetics. Silicate weathering increases relative to carbonate during the dry season, and may be more predominant in groundwater with longer water-rock interaction times. Despite this kinetic effect, silicate weathering fluxes are dominated by the monsoon flux, when between 50% and 70% of total annual silicate weathering flux occurs.     

Strains developed in the hangingwalls of thrusts due to their slip/propagation rate: A dislocation model

Fault planes propagate radially from a point source and this failure propagation process is very similar to the movement of a dislocation through a crystal lattice. An elastic strain represented by an extra half plane is necessarily imparted to the lattice at an edge dislocation, and this is equivalent to the ductile bead which accompanies the propagating tip of a thrust fault. This ductile bead migrates with the fault tip, and imparts a characteristic internal strain to the thrust sheet. A two-dimensional model is presented to illustrate the inter-relationship between fault plane slip, fault tip propagation and internal strain. In multilayered sequences, internal strain is usually represented by asymmetric folds verging in the thrust transport direction. A simple technique, the displacement/distance plot utilizes the fact that displacement dies out towards the fault tip. This plot can be used to quantify the relative stretch, measured parallel to the fault movement, which is dependent on the slip/propagation rate, and it may be used to define exactly the position of the fault tip on a cross-section. Examples of fold-thrust structures from Devon (England) and Pembrokeshire (Wales) are used to illustrate the technique.     

Lead ages,reset rubidium-strontium ages and implications for the Archaean crustal evolution of the Diemals area,Central Yilgarn Block,Western Australia

The Pb-Pb whole-rock geochronology of Archaean granitic and gneissic rocks from the Diemals area in the Central Yilgarn granite-greenstone terrain provides important constraints on crustal evolution. The regionally extensive banded gneisses, previously considered as candidates for basement to the greenstones give a Pb-Pb whole-rock age of 2700 ± 97 Ma (2σ errors). This is within error of previously published Rb-Sr and Sm-Nd gneiss ages and also within error of the Sm-Nd ages on the greenstones in the Eastern Goldfields Province. Two synkinematic plutons give Pb-Pb whole-rock ages (2737 ± 62 Ma and 2700 ± 100 Ma) and Pb isotopic compositions consistent with the hypothesis, based on field and geochemical relations, that these plutons were derived by partial melting of the precursors to the banded gneisses. Assuming this, the combined data date the melting event at 2723 ± 25 Ma with a model source μ value of 8.18 ± 0.02. This source μ value is close to the range postulated for mantle values and restricts the crustal history of the precursors to less than ~200 Ma. A post-kinematic pluton with a whole-rock Pb-Pb age of 2685 ± 26 Ma and μ value of 8.26 ± 0.02 puts a younger limit on this relatively short lived crustal accretion-differentiation event.Comparison of Pb-Pb and Rb-Sr whole-rock dates for the plutons suggests that the latter became closed systems up to 200 Ma after the Pb-Pb ages, and that the plutons gained or lost Rb or Sr at this time.     

An Evaluation of USGS III

"Usable values" based on evaluation by the "select laboratories" method are presented for concentrations of many constituents of eight reference rocks from the U.S. Geological Survey. Comparisons are made between the derived values and those published earlier.     

Verification of route-based road weather forecasts

Route-based road weather forecasting is increasingly becoming the standard methodology for winter maintenance decision making (i.e. whether or not to salt the road network) by the highway industry in the UK. Route-based forecasting requires, for the first time, the accuracy of forecasts around routes and away from sensor sites to be verified. This is essential so that end users have confidence in the models’ ability to accurately predict road surface temperature at every point around their road network. A new methodology for verifying route-based forecasts is proposed that uses clustering techniques to create clusters of forecast points with similar geographical and infrastructure characteristics. This facilitates the analysis of forecast statistics at the cluster level, which is found to improve statistical assessment of model performance since verification can be achieved at a much higher resolution than the current methodology allows. Furthermore, verification of the full spatial extent of a route-based forecast can be achieved with fewer forecast points since the majority of thermal variations around the road network are well represented by the clustering solutions. A new sampling strategy is proposed that potentially enables verification at the full spatial and temporal resolution.     

Climate change and road freight safety: a multidisciplinary exploration

The freight and logistics sector is of significant importance as an enabler and driver of the global economy, but it is also inherently vulnerable to hazardous weather. Despite this, there is currently no quantitative assessment of how climate change may affect the sector. This paper applies multidisciplinary climate change impact assessment tools and conceptual frameworks to the road freight sector of Great Britain in order to identify potential future weather-related safety issues. Relationships between weather and freight accidents are determined using road accident data and meteorological observations, which are then used with climate change scenarios to arrive at projections of possible impacts across the regions of Great Britain. Included in the study are industry perceptions of future trends within the sector and wider economy which many affect freight’s exposure and sensitivity to weather. These are elicited through interviews and an iterative expert Delphi study. Hence, unlike many other climate change impact assessments, this innovative study takes into account the potentially significant impact of socio-economic change (including institutional and operational). The results show that summer precipitation and winter ice-related accidents are likely to decrease across most of the country, whereas winter rain-related accidents are projected to increase. However, it is postulated that some of the impacts of climate change will be modified by reflexive behavioural change on the part of the driver and either institutional adaptation or complacency on the part of the road authorities. The paper concludes by framing the study in a range of future scenarios outlining how the socio-economic environment could influence the road transport network and how it is used, modifying the impact of climate change.