The research presented in this thesis involves the study of ice cloud microphysical and optical properties using both hyperspectral and narrowband infrared spectral data. First, ice cloud models are developed for the Infrared Atmospheric Sounding Interferometer (IASI) instrument onboard the METOP-A satellite, which provide the bulk-scattering properties of these clouds for the 8461 IASI channels between 645 and 2760 cm-1. We investigate the sensitivity of simulated brightness temperatures in this spectral region to the bulk-scattering properties of ice clouds containing individual ice crystal habits as well as for one habit distribution. The second part of this thesis describes an algorithm developed to analyze the sensitivity of simulated brightness temperatures at 8.5 and 11.0 µm to changes in effective cloud temperature by adjusting cloud top height and geometric thickness in a standard tropical atmosphere. Applicability of using these channels in a bi-spectral approach to retrieve cirrus cloud effective particle size and optical thickness is assessed. Finally, the algorithm is applied to the retrieval of these ice cloud properties for a case of single-layered cirrus cloud over a tropical ocean surface using measurements from the Moderate Resolution Infrared Spectroradiometer (MODIS). Cloud top height and geometric thickness in the profile are adjusted to assess the influence of effective cloud temperature on the retrieval.

The low temperature spin dynamics of the canonical dipolar spin ice materials is examined. The ac susceptibility of dipolar spin ice materials Ho2Ti2O7 and Dy2Ti2O7 is measured to lower temperatures and frequencies than previous studies. This provides a probe of the dynamics of fractionalized magnetic excitations which have been found to exist and interact as monopole-like particles within the spin ice con guration. Low temperatures and low frequencies access the dilute monopole phase, and provide a valuable stress case scenario to theory which has been used to describe the system to date. The relaxation is found to be well described at the lowest temperatures by an Arrhenius law with single energy barrier for both Ho2Ti2O7 and Dy2Ti2O7, with similar barriers to relaxation, 10.7 K and 9.79 K respectively. It is also revealed to be distinctly different from predictions of the dipolar spin ice model, based upon simulations of both a Coulomb gas and dipolar spin ice on the pyrochlore lattice. These simulations, as well as calculations based on Debye-Huckel theory, do not see Arrhenius behaviour in our temperature range, and do not predict the rate at which dynamics freeze out. It is not currently understood what would be required in order to amend this. The implications for thermal methods of probing spin dynamics is discussed, as well as how this measurement impacts the magnetolyte theory of spin ice. Brief reports are presented in the appendices of specific heat measurements of three spin liquid candidates: Yb2Ti2O7, Tb2Ti2O7, and Pr2Hf2O7. In Yb2Ti2O7, measurements of three single crystals, two unique features, a broad anomaly at 195 mK and sharp peak at 265 mK, are found which seem to comprise elements of previous single crystal and polycrystalline measurements. These low temperature features do not correspond to changes in neutron scattering intensity at 400 mK. In Tb2Ti2O7, a second order transition is found, corresponding to the emergence of a mode in inelastic neutron scattering. Absence of an ordering transition in the suspected <111> antiferromagnet Pr2Hf2O7 is also shown, with specific heat measured down to 100 mK with no ordering transition.

Hydrogen appears to be a clean and sustainable fuel for transportation vehicles, including internal combustion engine vehicles. In this research, a 1986 GMC Sierra truck with a 350CID 5.7L V8, 4 barrel carbureted Chevrolet gasoline engine is converted to burn hydrogen as a sustainable and envirnmentally benign fuel with a shorter energetic cycle. It demonstrates that the problems of backfire can be eliminated using several less expensive methods, such as employing cold spark plugs with reduced spark gap and low temperature cooled valves along with the introduction of water vapor to the mixture. In the experiments, the internal combustion engine was tested for two fuels: (i) octane 95 gasoline, and (ii) gaseous hydrogen at 99% purity. The vehicle underwent dynamometer tests using both the gasoline and hydrogen fuels for performance comparisons. A comprehensive thermodynamic analysis, through energy and exergy, of the engine is conducted for both cases: (i) with the octane 95 gasoline fuel and (ii) with hydrogen gaseous fuel. The performance results through energy and exergy efficiencies are compared for possible improvements. The mileage and energy efficiencies calculated and tested using this engine showed that it is more efficient operating on gasoline fuel rather than hydrogen. This is explained fully in the thesis as to the properties of hydrogen and gasoline fuels that differ, and the particular vehicle technology makes this difficult to achieve a reasonable mileage and efficiency. / UOIT

Accumulation of dynamic and thermodynamic forces in the Arctic are decreasing the extent of thin annual sea ice which polar bear rely on for survival. It is imperative that we identify the preferred habitat of polar bears to fully understand their future requirements. In this thesis, surveys of polar bear tracks and the surrounding sea ice variables, at various scales, were recorded. Sea ice roughness was measured through surveys of the sample area in situ, with an electromagnetic induction (EM) system (IcePIC) mounted to a helicopter, and analyzed through advanced synthetic aperture radar (ASAR) images of the study area. In situ Polar bear tracks provided a limited association with the EM sea ice roughness and a negative association to ASAR sea ice roughness. Results indicate a significant association between EM mean values and ASAR brightness means. In addition, EM statistics and ASAR texture statistics were correlated through a best fit regression model. These associations display a remote method to identify preferred polar bear habitat and provide a potential linkage between the regional (EM) and remotely sensed (ASAR) assessment of sea ice roughness. / October 2008

This work aims to increase our understanding of the nature of large scale features of sea ice from a dynamics point of view.Sea ice plays an important part in the exchange of heat and humidity between sea and air and thus is an important component of the climate system. Its physical presence also directly impacts the various forms of life such as diatoms, polar bears and humans alike.The dynamics of sea ice affect both weather and climate, through the large scale drift in the Arctic from the Siberian coast towards Fram Strait, through creation of cracks in the ice called leads or polynyas, and through ridging and other mechanical deformations of ice floes.In this work, we have focused on modelling of ridged ice for a number of reasons. Direct observations of the internal ice state is very difficult to perform and in general, observations of sea ice are either sparse or of limited information density. Ridged ice can be seen as the memory of high ice stress events, giving us a view on these highly dynamic events. Ridging is of major importance for the ice thickness distribution, as the thickest ice can only be formed through mechanical processes. Further, ridged ice is of direct interest for anyone conducting shipping through seasonal or perennial ice covered seas as it can form impenetrable barriers or in extreme even cases crush a ship caught within the ice pack. To this end, a multi-category sea ice model, the HELsinki Multi category Ice model (HELMI), was implemented into the Rossby Centre Ocean model (RCO). HELMI has explicit formulations for ridged and rafted ice, as well as sub-grid scale ice thickness distribution (a feature shared with other multi category models) and an ice strength based on energetics. These features give RCO better representation of sub-grid scale physics and gives us the possibility to study the deformed ice in detail. In paper I we look at the change in behaviour in the Arctic as the ice becomes more mobile, leading to a slight increase in modelled ridged ice volume in the central Arctic, despite a general trend of a decreasing ice cover.Paper II takes us to the Baltic Sea and the possibilities of modelling ridge ice concentration with a statistical model.In Paper III we investigate how the diminishing ice cover in future scenarios affects the biological activity in the Baltic Sea.Finally Paper IV investigates how the ice stress and the internal ice force can be interpreted in terms of ice compression on the ship scale. / <p>At the time of the doctoral defence the following paper was unpublished and had a status as follows: Paper 4: Manuscript</p>

The research presented in this thesis involves the study of ice cloud microphysical and optical properties using both hyperspectral and narrowband infrared spectral data. First, ice cloud models are developed for the Infrared Atmospheric Sounding Interferometer (IASI) instrument onboard the METOP-A satellite, which provide the bulk-scattering properties of these clouds for the 8461 IASI channels between 645 and 2760 cm-1. We investigate the sensitivity of simulated brightness temperatures in this spectral region to the bulk-scattering properties of ice clouds containing individual ice crystal habits as well as for one habit distribution. The second part of this thesis describes an algorithm developed to analyze the sensitivity of simulated brightness temperatures at 8.5 and 11.0 µm to changes in effective cloud temperature by adjusting cloud top height and geometric thickness in a standard tropical atmosphere. Applicability of using these channels in a bi-spectral approach to retrieve cirrus cloud effective particle size and optical thickness is assessed. Finally, the algorithm is applied to the retrieval of these ice cloud properties for a case of single-layered cirrus cloud over a tropical ocean surface using measurements from the Moderate Resolution Infrared Spectroradiometer (MODIS). Cloud top height and geometric thickness in the profile are adjusted to assess the influence of effective cloud temperature on the retrieval.

Open water in sea ice, such as leads and polynyas, plays a crucial role in determining the formation of deep- and bottom-water, as well as their long-term global properties and circulation. Ocean general circulation models (GCMs) designed for studies of the long-term thermohaline circulation have typically coarse resolution, making it inevitable to parameterize subgrid-scale features such as leads and convective plumes. In this study, a hierarchy of higher-resolution sea-ice models is developed to reduce uncertainties due to coarse resolution, while keeping the ocean component at coarse resolution to maintain the efficiency of the GCM to study the long-term deep-ocean properties and circulation. The higher-resolved sea-ice component is restricted to the Southern Ocean. Compared with the coarse sea-ice model, the intermediate, higher-resolution version yields more detailed coastal polynyas, a realistically sharp ice edge, and an overall enhanced lead fraction. The latter gives enhanced rates of Antarctic Bottom Water formation through enhanced near-boundary convection. Sensitivity experiments revealed coastal katabatic winds accounted for in the higher resolution version, are the main reason for producing such an effect. For a more realistic coastline, satellite passive-microwave data for fine-grid land/ice-shelf – seaice/ ocean boundary were used. With a further enhancement of the resolution of the Southern Ocean’s sea-ice component, a grid spacing of 22 km is reached. This is about the size of the pixel resolution of satellite-passive microwave data from which ice concentration is retrieved. This product is used in this study to validate the sea-ice component of the global ocean GCM. The overall performance of the high-resolution sea-ice component is encouraging, particularly the representation of the crucial coastal polynyas. Enhancing the resolution of the convection parameterization reduces spurious coarse-grid polynyas. Constraining the upper-ocean temperature and modifying the plume velocity removes unrealistic small-scale convection within the ice pack. The observed highfrequency variability along the ice edge is to some extent captured by exposing the ice pack to upper-ocean currents that mimic tidal variability. While these measures improve several characteristics of the Southern Ocean sea-ice pack, they deteriorate the global deepocean properties and circulation, calling for further refinements and tuning to arrive at presently observed conditions.

Thesis (M.S.)--University of Missouri-Columbia, 2003. / Typescript. Includes bibliographical references (leaves 61-63). Also available on the Internet.

Thesis (M.S.)--University of Missouri-Columbia, 2003. / Typescript. Includes bibliographical references (leaves 61-63). Also available on the Internet.

Miljöbyggnad is a Swedish system for certifying building in regarding to energy, indoor climate and materials. Energy usage in built environment occupies more than a third of total energy consumption and greenhouse gas emissions in Sweden (SEA, 2008). Among fifteen indicators regulated by Miljöbyggnad, four indicators which consist of specific energy use, thermal climate winter, thermal climate summer and daylight have been analyzed in this report. There has two objectives for the project. The first objective is to make optimized approaches for the building according to baseline simulation model. And the second objective is to make assessment of the optimized model based on Miljöbyggnad environmental certification. As a conclusion, the implemented approaches helped to improve indoor thermal comfort and decrease demand of operational electricity for lighting. The four analyzed indicator of the optimized model have achieved GOLD level according to criteria regulated by Miljöbyggnad.