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This mini-dissertation aims to examine the way in which Breyten Breytenbach explores the concepts of home and exile in his novel Memory of Snow and of Dust. The author captures and conveys the experience of exile, and envisages through the exile’s double vision a more complicated conception of home. Through the novel one is able to observe the exilic condition and gain access to new insights. The narrative structure comprises of various discourses and illustrates the restless nature of an unsettling and unstable existence. In the Introduction the theoretical framework for this study is outlined: recent developments in postcolonial and postmodern theories, Breytenbach’s oeuvre and literary criticism devoted to his work are discussed. Chapter One examines the distressing journey into a new awareness of what constitutes home. Chapter Two inspects the restless, yet regenerative condition of exile. Chapter Three considers a more fluid response to spatiality and the concept of home through an exploration of fresh perspectives that may emerge from extreme mental suffering. This study concludes with an affirmation of the relevance of Memory of Snow and of Dust, in times in which the overlapping boundaries of home and exile are becoming a global condition. / Thesis (M.A.) - University of KwaZulu-Natal, Durban, 2010.

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Glacial geomorphology contains information about former climate which is required for modelling global climate change. Most peaks over 5500 m in the Cordillera Occidental show signs of former glaciation although few at present support perennial ice. Cirque headwalls, large sub-parallel lateral moraines, terminal moraines and minor re-advance moraines were measured at six representative study sites, as were active and inactive rock glaciers. The largest sets of lateral moraines are assumed to have formed when glaciers were in equilibrium at the peak of the last glaciation, and a succession of minor re-advance moraines was probably deposited during retreat of the ice. The radiometric age determinations corroborate existing opinion that this retreat began in the central Andes around 14 000-11 500 years BP. Reconstructed former equilibrium lines on fourteen selected palaeo-glaciers range in altitude from 4625 m at 16°S to 4775 m at 22°S. Five methods of former ELA reconstruction were tested based on geomorphological evidence collected in the field. The results imply lowering of the ELA caused by lower temperatures and increased precipitation compared to the present. The maximum extent of glaciation in the Cordillera Occidental appears to have been reached late in the last glacier cycle because of a shortage of available moisture which inhibited glacier growth when temperatures were colder. Active rock glaciers appear to respond to the thermal rather than the hydric regime and terminate close to the 0°C isotherm which was 300 m lower during deglaciation than at present.

In this thesis freeze-thaw along roads in northern Sweden is examined. The examinations are put in a context of changing climate and its amplification towards the Arctic region on earth. The research focuses on the impact of a warmer climate on ground freeze-thaw and in exten- sion road maintenance in the region. The investigation is presented through two scientific papers, where the first examines how ground temperatures are developed during a single frost season experiment, where a natural accumulation of snow cover and a continual removal of snow cover occur respectively. In the second paper, ground temperature data from sub-Arctic Sweden that has been logged by the Swedish Transport Administration, has been collected and freeze-thaw cycles have been calculated and analysed. The results are related to regional landscape factors and are in the context of regional climate change discussed to reach understanding of challenges for road maintenance in the region and opportunities to reach resilience. The results in Paper 1 show that also a thin cover of snow has impact on the freeze-thaw frequency, duration and intensity that occur in and on the surface of the ground. Furthermore the results show that the ground temperatures rise in due to an increase in snow cover amounts and that this process occurs in several steps. Paper 2 shows that the occurrence of ground freeze-thaw is affected by the proximity to open waters. Warmer temperatures in the air may cause later ice freeze-up and earlier ice break-up on lakes, rivers and on the Gulf of Bothnia and roads in northern Sweden are in general situated on the coast or near rivers. Ground temperatures around 0 °C has a high negative impact on road stability and a warmer and wetter climate in northern Sweden may thus increase road deterioration. The economic development in Sweden stays dependent on extraction of natural resources in sub-Arctic Sweden and thus it is of major concern to main- tain and improve road infrastructure in the region.

Snow and lake ice have very high albedos compared to other surfaces found in nature. Surface albedo is an important component of the surface energy budget especially when albedos are high since albedo governs how much shortwave radiation is absorbed or reflected at a surface. In particular, snow and lake ice albedos have been shown to affect the timing of lake ice break-up. Lakes are found throughout the Northern Hemisphere and lake ice has been shown to be sensitive to climatic variability. Therefore, the modelling of lake ice phenology, using lake ice models such as the Canadian Lake Ice Model (CLIMo), is important to the study of climatic variability in the Arctic and sub-Arctic regions and accurate snow and lake ice albedo measurements are required to ensure the accuracy of the simulations. However, snow and lake ice albedo can vary from day-to-day depending on factors such as air temperature, presence of impurities, age, and composition. Some factors are more difficult than others to model (e.g. presence of impurities). It would be more straight forward to just gather field measurements, but such measurements would be costly and lakes can be in remote locations and difficult to access. Instead, CLIMo contains an albedo parameterization scheme that models the evolution of snow and lake ice albedo in its simulations. However, parts of the albedo parameterization are based on sea-ice observations (which inherently have higher albedos due to brine inclusions) and the albedo parameterization does not take ice type (e.g. clear ice or snow ice) into account. Satellite remote sensing via the Moderate Resolution Imaging Spectroradiometer (MODIS) provides methods for retrieving albedo that may help enhance CLIMo’s albedo parameterization. CLIMo’s albedo parameterization as well the MODIS daily albedo products (MOD10A1 and MYD10A1) and 16-day product (MCD43A3) were evaluated against in situ albedo observations made over Malcolm Ramsay Lake near Churchill, Manitoba, during the winter of 2012. It was found that the snow albedo parameterization of CLIMo performs well when compared to average in situ observations, but the bare ice parameterization overestimated bare ice albedo observations. The MODIS albedo products compared well when evaluated against the in situ albedo observations and were able to capture changes in albedo throughout the study period. The MODIS albedo products were also compared against CLIMo’s melting ice parameterization, because the equipment had to be removed from the lake to prevent it from falling into the water during the melt season. Cloud cover interfered with the MODIS observations, but the comparison suggests that MODIS albedo products retrieved higher albedo values than the melting ice parameterization of CLIMo. The MODIS albedo products were then integrated directly into CLIMo in substitution of the albedo parameterization to see if they could enhance break-up date (ice off) simulations. MODIS albedo retrievals (MOD10A1, MYD10A1, and MCD43A3) were collected over Back Bay, Great Slave Lake (GSL) near Yellowknife, Northwest Territories, from 2000-2011. CLIMo was then run with and without the MODIS albedos integrated and compared against MODIS observed break-up dates. Simulations were also run under three difference snow cover scenarios (0%, 68%, and 100% snow cover). It was found that CLIMo without MODIS albedos performed better with the 0% snow cover scenario than with the MODIS albedos integrated in. Both simulations (with and without MODIS albedos) performed well with the snow cover scenarios. The MODIS albedo products slightly improved CLIMo break-up simulations when integrated up to a month in advance of actual lake ice break-up for Back Bay. With the MODIS albedo products integrated into CLIMo, break-up dates were simulated within 3-4 days of MODIS observed break-up. CLIMo without the MODIS albedos still performed very well simulating break-up within 4-5 days of MODIS observed break-up. It is uncertain whether this was a significant improvement or not with such a small study period and with the investigation being conducted at a single site (Back Bay). However, it has been found that CLIMo performs well with the original albedo parameterization and that MODIS albedos could potentially complement lake-wide break-up simulations in future studies.

Variation in snow albedo feedback (SAF) among CMIP5 climate models has been shown to explain much of the variation in projected 21st Century warming over Northern Hemisphere land. Prior studies using observations and models have demonstrated both considerable spread in the albedo, and a weak bias in the simulated strength of SAF, over snow-covered boreal forests. Boreal evergreen needleleaf forests are capable of intercepting snowfall throughout the snow season, which has a significant impact on seasonal albedo. Two satellite data products and tower-based observations of albedo are compared with simulations from multiple configurations of the Community Climate System Model (CCSM4) to investigate the causes of weak simulated SAF over the boreal forest. The largest bias occurs in April-May when simulated SAF is one-half the strength of SAF in observations. This is traced to two canopy snow parameterizations in the land model. First, there is no mechanism for the dynamic removal of snow from the canopy when temperatures are below freezing, which results in albedo values in midwinter that are biased high. Second, when temperatures do rise above freezing, all snow on the canopy is melted instantaneously, which results in an unrealistically early transition from a snow-covered to a snow-free canopy. These processes combine to produce large differences between simulated and observed monthly albedo, and are the sources of the weak bias in SAF. This analysis highlights the importance of canopy snow parameterizations for simulating the hemispheric scale climate response to surface albedo perturbations. A number of new experiments are described as recommendations for future work.

Glaciated catchments increasingly accommodate rising populations. As glaciers are capable of modifying peak flows and releasing floodwaters, understanding and developing models of subglacial water storage and release has significance to the safety of resident populations and land use decision-making. Glaciological and hydrometeorological processes play a critical role in determining water storage within the subglacial drainage system of Alpine glaciers. However, our understanding of spatial variations of these processes throughout the ablation season remains incomplete. Field results and modelling studies of the glacial hydrological system at Findelengletscher, Canton Valais, Switzerland are presented with a view to improving understanding of physical mechanisms controlling water flow within glacierised catchments. A physically-based model of surface runoff incorporating meltwater and precipitation has been developed. This model has limited data requirements using only air temperature, solar radiation, precipitation and elevation of the transient snow line in a simple, spatially distributed energy balance model. It has been used to predict surface runoff at an hourly resolution for the 1999 ablation season. Methodological advances have been made by creating conceptual models of water flow through the subglacial drainage system. Models are used for semi-quantitative interpretation of water level variations in boreholes, as surrogate measures of subglacial water pressures. The boreholes either directly intersect subglacial channels or hydraulically connect to subglacial channels through a subglacial sediment layer. Variations in borehole water levels are considered at both diurnal and seasonal timescales. Water storage has been calculated within the subglacial drainage network and interpretations are made of temporal variations in subglacial water storage. Borehole water levels indicate that the glacier subsole can be spatially separated into those areas that are hydraulically connected or unconnected to the subglacial drainage system. Hydraulically connected areas may further be subdivided into areas of efficient and inefficient subglacial drainage. These may intermittently connect and influence water balance within a glacier. Increasing and decreasing trends in water balance cycles are initiated by glaciohydrological mechanisms. These control the activity of intermittent hydraulic connections between efficient and inefficient areas of subglacial drainage. Connections form in response to two hydrometeorological factors: high elevation rainfall and short duration decreases in elevation of either the snowline or the 0°C isotherm. Increasing trends in water balance over successive days are associated with preferential routing of inputs into, and retention within, hydraulically inefficient areas of the subglacial drainage system. Occasionally the release of water from temporary subglacial storage is not synchronous with either hydrometeorological causal factor. Measurements of fall-line velocity and vertical displacement suggest that basal sliding may alter preferential subglacial flow pathways. However, uncertainty exists as to whether such changes may be the result of lagged effects of either high water pressures from rainfall or low water pressures from low daily surface runoff. These uncertainties are due to system response times affecting the time taken to transfer longitudinal strain within glacier ice. In the late ablation season the potential for rapid surface runoff over the annual maximum snowfree area within the catchment is high. In the event of a large rainfall event the capacity of a tunnel-conduit system to discharge may have decreased sufficiently to cause temporary retention of a large proportion of surface runoff, predominantly within distributed drainage. Temporary storage followed by re-integration of hydraulic connections formed earlier in the ablation season, increases the potential for proportionally large discharge events (relative to the volumes of inputs) in the late ablation season. Flooding in glacierised basins becomes more likely as a result.

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