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The coupled upper atmospheres, ionospheres and magnetospheres of the planets were the subject of a joint RAS–G/MIST discussion meeting hosted by the RAS on 10 January 2003, organized by Ingo Mueller-Wodarg and Emma Bunce . The scientific programme consisted of 10 presentations by speakers from the UK, France, USA and Australia. 相似文献
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Michael Bunce 《Geoforum》2008,39(2):969-979
The transformation of rural areas into up-scale leisure amenity landscapes has become a global phenomenon. Small islands, especially in tropical and subtropical regions, are particularly attractive magnets for this kind of development. Yet it involves land use changes that challenge the sustainability of small island development as set out in the United Nations program for Sustainable Development of Small Island Developing States (SDIDS). Through a case study of Barbados this paper critically examines the ‘leisuring’ of rural landscapes on small islands. It ties together Lefebvrian concepts of the production of space with the perspective of political ecology to argue that the agendas of global capital impose new spatialities involving social constructions of space and socio-environmental transformations by an offshore elite who are insensitive to local interests as well as the smallness of small islands. This creates conflict between space and place - between the spaces produced by the global leisure economy and the places that have purpose and meaning for local people. It challenges the possibility of local, community-based development solutions and imposes serious constraints on the implementation of the SDIDS agenda. More research into the nature of the new leisure spaces and how they are perceived and experienced by local populations is needed. 相似文献
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We present results from a theoretical model which has been used to investigate the modulation of the magnetosphere-ionosphere coupling currents in the Jovian middle magnetosphere by solar wind-induced compressions and expansions of the magnetosphere. We consider an initial system in which the current sheet field lines extend to 50RJ in the equatorial plane, and where the iogenic plasma in the current sheet undergoes steady outward radial diffusion under the influence of the ionospheric torque which tends to maintain corotation with the planet. We show using typical Jovian parameters that the upward-directed field-aligned currents flowing throughout the middle magnetosphere region in this system peak at values requiring the existence of significant field-aligned voltages to drive them, resulting in large precipitating energy fluxes of accelerated electrons and bright ‘main oval’ UV auroras. We then consider the changes in these parameters which take place due to sudden expansions or compressions of the magnetosphere, resulting from changes in the solar wind dynamic pressure. Two cases are considered and compared, these being first the initial response of the system to the change, determined approximately from conservation of angular momentum of the radially displaced plasma and frozen-in field lines, and second the subsequent steady state of steady outward radial diffusion applied to the compressed or expanded system. We show that moderate inward compressions of the outer boundary of the current sheet field lines, e.g. from 50 to 40RJ, are effective in significantly reducing the coupling currents and precipitation in the initial state, the latter then recovering, but only partly so, during the evolution to the steady state. Strong inward compressions, e.g. to 30RJ cause significant super-corotation of the plasma and a reversal in sense of the current system in the initial state, such that bright auroras may then be formed poleward of the usual ‘main auroral oval’ due to the ‘return’ currents. The sense of the currents subsequently reverts back to the usual direction as steady-state conditions are restored, but they are weak, and so is the consequent electron precipitation. For outward expansions of the current sheet, however, the field-aligned currents and electron precipitation are strongly enhanced, particularly at the poleward border mapping to the outer weak field region of the current sheet. In this case there is little evolution of the parameters between the initial expansion and the subsequent steady state. Overall, the results suggest that the Jovian middle magnetosphere coupling currents and resulting ‘main oval’ auroral acceleration and precipitation will be strongly modulated by the solar wind dynamic pressure in the sense of anti-correlation, through the resulting compressions and expansions in the size of the magnetosphere. 相似文献
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Matthew Bunce Laurence Mee Lynda D. Rodwell Richard Gibb 《Global Environmental Change》2009,19(2):213-226
Few studies consider how social-ecological systems recover from disturbance. We consider the small semi-autonomous island of Rodrigues (Indian Ocean). Based on semi-structured interviews (n = 70), a fisher survey (n = 73), weather data and official records we build a timeline of key events. We tabulate local perceptions (5+ mentions) of changes (social, economic and natural capital) and look for signs of adaptive cycles in the island's social-ecological past. Rising human pressure and extreme weather event impacts are reported since first settlement. We propose a recent “collapse” phase catalysed in the 1970s by severe drought, based on respondents’ perceptions of still-ongoing changes in farming and fishing, water, external dependence, migration and inter-island political change. Connectivity (flows of people, goods, information, money, power) appear to have strengthed local island recovery, but degradation continued, not least due to water scarcity and a lack of shared political vision as Rodrigues became more tied into the wider world.Overall, our findings suggest social-ecological systems may get stuck in a post-collapse recovery without any new structure emerging, presuming adaptive cycles can even be detected. Data gaps and global change redefining spatial and temporal scales could mean the adaptive cycle's usefulness is limited in development policy-making contexts. 相似文献
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Integrating global and regional analyses of the effects of climate change: A case study of land use in England and Wales 总被引：3，自引：0，他引：3
M. L. Parry J. E. Hossell P. J. Jones T. Rehman R. B. Tranter J. S. Marsh C. Rosenzweig G. Fischer I. G. Carson R. G. H. Bunce 《Climatic change》1996,32(2):185-198
The purpose of this paper is to exemplify a means by which an integrated assessment can be made of global and regional effects on land use of climate change. This is achieved by use of data on the effects of climate change on world food prices as inputs to a regional land use allocation model.Data on world prices are drawn from a recent global study of climate change and crop yields. In a case study of England and Wales a land allocation model is used to infer changes of land use that are the product of the integrated effect of climate-induced global price changes and climate-related changes of yield in England and Wales. This combination of changed prices and yield potential is used to calculate the land use providing the highest returns for each of 155,235 1 km2 cells of land in England and Wales for a future assumed for the year 2060 (without climate change) and then for that same environment with climate change. The difference between these two is then treated as an estimated effect resulting from climate change. 相似文献
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