Two models are presented in the thesis. The first modelling approach used is to apply a three-dimensional ice sheet model (GLIMMER) to test the sensitivity of selected small glaciers to growth and disappearance. This feeds into an original mass-balance and vegetation cover model, built using meteorological data, that has been used to connect glacier mass balance with vegetation cover in the study regions on an annual and monthly timescale. This model has been used to evaluate spatial and temporal environmental responses to changes in temperature and precipitation of known magnitude, and to test the response to long timeseries of temperature data. At Skeiðsvatn, lacustrine evidence indicates the onset of Late Holocene glaciation around A.D. 650, and that glaciation of the catchment has continued uninterrupted to the present day. Consequently this constrains the warmth of the MWP, while terminal moraines constrain both Little Ice Age and earlier Neoglacial advances. The new modelling approach has provided key insights into the many different ways in which climate and environment interact over a varied topography, with consequently diverse effects upon settlement.

A mean monthly temperature record is reconstructed for 50-year periods for Edinburgh, in the millenium 800-1900 AD. The development of a reliable record of past climate for Edinburgh and south-east Scotland permits the study of the significance of past climatic change on humans in these regions. First, the possible influence of climate on agriculture is investigated over the last 800 years. Specifically, a replication study of M.L. Parry's (1972) classic thesis, 'Changes in the Upper Limit of Cultivation in South-East Scotland: 1600-1900 AD', is undertaken. Second, the possible influence of climate on disease is investigated. The diseases covered include the bubonic plague, malaria, and ergotism. Finally, the new mean monthly temperature record for Edinburgh is used as an historical analogue for possible greenhouse-gas induced warming in south-east Scotland. Because the record is sufficiently detailed, the possible influence of the predicted warming on agriculture and two communicable diseases, namely Lyme disease and Leptospirosis is investigated.

This study establishes an empirical predictive model of N₂O and NO emissions for Great Britain based on multivariate regression analysis of field measurement data from several studies in European countries and the USA for which the results have been published in the last 18 years. The significance of studying the emissions of these gases is due to the role of N₂O as a greenhouse effect gas and NO participation in reactions with ozone. Soils are known to be an important source of N₂O and also contribute significant amounts of NO into the atmosphere. Knowledge of N₂O and NO emissions from soils at a national scale is important due to the signed international agreements which oblige Great Britain to produce inventories of greenhouse effect gases and monitor the emissions of NOx gases. The field studies observed the relationships between the emissions and their controlling factors and on the basis of those relationships, national modelling approaches to predicting the amounts of emissions have been defined. Due to the highly variable nature of emissions, more than one empirical model was developed for each of the gases. The relationships defined in the analysis were later applied to estimate N₂O and NO emissions from British soils with an application of input parameter data of the established controlling factors in the framework of ArcInfo GRID. Data of N fertiliser input, soil moisture and temperature were not readily available and therefore had to be estimated with existing data. Soil moisture was predicted with the SPACTeach model based on the monthly precipitation sums obtained from the Climate LINK data set. This data source also provided monthly air temperature data used to model soil temperature with the theory of heat flux. N input was estimated as a sum of mineral and organic N fertiliser inputs from agriculture and atmospheric N deposition.

This thesis describes investigations into techniques for measuring trace gas emissions from soils, and related modelling activities. Using nitrous oxide, N₂O, as an example, two major questions concerning the closed chamber technique have been studied. A major source of potential error has been identified in a commonly used chamber design that includes a vent tube to equalise inside and outside pressures. It was found that depressurisation of the chamber due to the Venturi effect led, depending on wind speed, to up to five-fold over-estimations in flux. Also, previous modelling exercises have assumed that the trace gas source in the soil remains at constant concentration, and consequently predicted non-linear accumulation in the chamber, requiring repeated sampling during chamber closure to make a flux measurement. However, measurements commonly show little departure from linearity, rendering repeated sampling superfluous, and modelling the process on the basis of a more realistic constant production by the source has explained these results. Another model has been developed to predict N₂O fluxes at a field scale, based on the measurement of three key parameters in the soil: temperature, water-filled pore space and mineral N content. This has given a good fit with measured fluxes from grassland and cereal fields, but not from some other crops. With regard to methane, CH₄ fluxes from a rice field were measured over two full growing seasons by the closed chamber technique. Additional measurements made it possible to differentiate between the two main emission pathways, namely via the plant and by ebullition. Temporal variations in CH₄ flux are discussed in relation to these processes.

Novel instrumental techniques have been conceived, developed and in one case, patented, which were employed to investigate various aspects of atmospheric dispersion and related topics. The first technique made use of unipolarly ionised air as the tracer 'material', and the results obtained formed the earliest direct experimental evidence of significant concentration fluctuations in vapour/particulate clouds dispersing in the lower atmosphere. Fluctuations are important because they are critical in determining the physiological response associated with exposures to toxic substances and those of importance in malodour nuisance. Later developments in technique included precision control of the unipolar ion current released; these were sufficiently novel to secure a patent. Subsequent innovations involved the development and substantial modification of an existing gas detection method to render its performance fully acceptable for pollution monitoring. This advance led to the invention of the UVIC® detector, described in Volume II, and generated the numerous patent applications referenced therein. Several papers discuss the nature and implications of the information obtained using the experimental methods developed. Examples are the open terrain atmospheric dispersion experiments and analyses, the work on insect pheromones and that on dispersion around an isolated building. From these papers, notably the first, the full impact of concentration fluctuations on the assessment of risks associated with exposure to toxic substances began to emerge. Two papers are included on the investigation of electric field effects arising from factory chimney plumes. Prior to publication, the existence of this phenomenon was not recognised. Papers on the use of electrically charged aerosols for improving deposition efficiency in crop spraying and on the examination of the effects of electrical charging on the behaviour of mildew spores, demonstrate the application of electrical techniques to novel areas of research. It is shown that the method may also have utility for wind tunnel investigations.

Aeolian dust studies are of global importance due to the impact of mineral dust on global climate, human health and the environment. Recent research, for example IPCC (2007) highlighted the important effects of atmospheric dust on global climate that has led to an increased interest in wind-blown mineral dust. Despite this increased interest, there is a dearth of field observations from dust sources due to their remoteness and hostility. This has limited the overall understanding of dust emission and led to an over-reliance on model predictions. Thus, there is a strong requirement for field observations to validate model predictions, especially for the Earth's greatest dust source- the Bodele Depression. This study aims to fill this gap by providing a quantitative description of dust emitted at a field study area within the Bodele Depression. This research demonstrates that particle size data can be used to characterise windblown sediments and produce information regarding dust emission mechanisms. The data revealed much evidence of aeolian abrasion that formed the foundation for several research hypotheses that were tested statistically using outputs from a dust emission and sandblasting model. Findings showed that sandblasting is significantly correlated with dust emission and plays a key role in dust emission. The spatial variation in dust emission at the field study area results from spatially heterogeneous aeolian abrasion that is driven by variation in sediment composition (mineralogy) and particle size. The aeolian abrasion of diatomite by quartz grains is a highly efficient mechanism of dust production in the field study area and this was validated by laboratory experiments. This study demonstrates the importance of controls on dust emission that need greater emphasis in dust schemes and makes recommendations for adjustments to models. The findings in this study have important implications for dust schemes that underestimate the roles of mineralogy and particle size since they are so influential in dust production and emission. This research improves the current understanding of dust emission and advances the ability to more accurately predict dust emission.

This thesis examines the way in which remote sensing instrumentation can be used to advance our understanding of the interactions between complex terrain and the atmospheric boundary layer (ABL). When mean flow speed is of moderate strength and the ABL is stable, mechanical effects will dominate thermal effects in modifying flow speed and direction. Boundary layer measurements were made using the scanning Salford 10 micron pulsed CO2 Doppler lidar during the 2005 Convective Storm Initiation Project (CSIP), above the heterogeneous orography that surrounds Faccombe, Hampshire, UK. A new method of detecting boundary layer flow perturbations was developed, and successfully applied to the lidar data, giving a clearer insight into flow modification that occurs above complex terrain. The observations are compared to the output from a simple one dimensional boundary layer flow prediction numerical model, and the three dimensional Computational Fluid Dynamics model (CFD), WRF (Weather Research and Forecasting). Reasonable correlation was found between the lidar data and the simple model output; however, the model results are spatially limited and have many associated assumptions, which are discussed. The WRF model was found to be adequate at predicting flow differences at lower altitudes, outputting well defined structures consisting of perturbed flow. However, this model tended to under predict the details of flow difference at higher altitudes in comparison to the CSIP lidar observations. The inability of WRF and similar CFD models to predict the detailed effects of orographically induced variation on upper level ABL flow is of concern, as the inaccuracies affect the performance of such models in reproducing flows on scales of importance in forecasting local weather and pollutant dispersion.

Atmospheric boundary layer height is one of the most important parameters in atmospheric dispersion modelling because it has a large effect on predicted air quality. Comparisons between Atmospheric Dispersion Modelling System, version 4 (ADMS 4) and lidar data were carried out on boundary layer height data from central London. The comparison showed that the boundary layer height predicted by the ADMS 4 was, on average, lower than lidar for the subset of data taken. ADMS 4 has a very simple surface scheme which is not representative of complex urban environments and the results from this research imply that there is not sufficient surface roughness within the model to produce a large enough boundary layer height. This research aims to create an improved urban surface scheme to better forecast the growth of the daytime urban boundary layer in air quality dispersion models using lidar measurements. Improved performance of ADMS in an urban area was achieved by a number of steps carried out in this study. They were: establishing the weaknesses of ADMS, developing a combined model for atmospheric boundary layer height, sensitivity analysis and validation. The combined model was developed by combining a surface model and the atmospheric boundary layer height model. Measurements of the atmospheric boundary layer height by lidar used backscatter and vertical velocity variance. However, vertical velocity variance was chosen for comparison with the combined model. Statistically, the combined model was better than ADMS. Sensitivity analysis, which used reasonable ranges of meteorological data for the UK, encompassed surface roughness, friction velocity, sensible heat flux and potential temperature gradient above the atmospheric boundary layer and the atmospheric boundary layer height. A good agreement was observed between the combined model and lidar measurement using data collected at a site in Greater Manchester. The overall conclusion was that the combined model improved the performance of ADMS in urban areas.

Implementation of Variable Geometry during the off-design operation of an aero gas turbine engine may cause deviations for restricted engine parameters when fight envelope requirements are met. A method to optimize the thermodynamic cycle of a engine with respect to fuel burn, while meeting a variety of airframe or technological restrictions at the three major operating points of the fight envelope, namely the Top of Climb, End of Runway and mid-cruise points is developed. Purpose is the comparison of engines on a common basis. The method is implemented and performance benefits are identified in a variety of studies, such as: o the theoretically infinite Variable Geometry in turbomachinery components o reduction of the turbine coolant fraction during cruise for long range civil fights o optimal variable nozzle geometry implementation during steady state and transient operation Core of the optimization procedure is a zero-dimensional engine arithmetic solver developed by the author from scratch for a 3-spool and 2-spool engine configuration. The solver utilizes real gas properties and an approximate dimensionless enthalpy rise profile at the fan exit for the separate modeling of the fan tip and hub region. Purpose for the development of the new code has been a common arithmetic treatment for steady-state and transient calculations within the same engine solver, which is thoroughly described.

The Along Track Scanning Radiometers (ATSR-1&2) on ESA's Remote Sensing Satellites (ERS-1&2) are validated using in situ radiometric data from Mutsu bay, Japan. One validation point for ATSR-1 was obtained and it was found to have an offset of -0.03K from the in situ radiometric data. Four validation points were obtained for ATSR-2 and it was fund to have an offset of 0.070.17 K in this region. The so-called 'skin effect' is investigated to improve the characterisation of the ocean-atmosphere interface. The two contrasting data sets - one from sheltered waters and one from open ocean are compared. The data presented here show that, in open oceans, at wind speeds greater than 6ms-1, T tends to a constant value of about -0.140.1K. The in situ radiometric data were taken using the SISTeR radiometer, designed and built by T.J. Nightingale. The absolute accuracy of this radiometer is assessed over a number of years and during the last campaign was found to be better than 0.025 K with an rms error (with a clean scan mirror) of less than 0.03 K. The data sets required to do this work were collected during 3 field campaigns during the summers of 1996, 1997 and 1998. MUBEX'96 and '97 took place in Mutsu Bay, Japan and CHAOS'98 was a research cruise from Tenerife to Iceland on the RRS Discovery.