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The simulation of Sea-ice in a coarse resolution ocean general circulation model is examined in Hudson Bay and surrounding waters. Sea-ice distribution and duration compared well to climatological values, although ice thickness is undersimulated as it is in other modelling work. In Hudson Bay ice thickness variation was dominated by the atmospheric forcing as shown by the symmetric response of ice thickness to warming and cooling scenarios. Below ice heat fluxes play a more significant role in Foxe Basin and Baffin Bay where they mitigate air-ice heat loss by as much as 40 percent, thus limiting ice thickness and duration. Below ice heat flux reduces by 23 percent for the region of study (Hudson Bay, Foxe Basin, Baffin Bay, and Labrador Sea) for a global 3°C cooling and increases by 9 percent for a 3°C global warming. This asymmetric response is attributed to the ocean's asymmetric response to warming and cooling scenarios. In so much as Hudson Bay is dominated by atmospheric forcing rather than under ice heat as these results indicate, coarse resolution models may be useful in assessing the impact of change. However the necessary reconfiguration of the model grid render results from Foxe Basin and Hudson Strait less credible. On étudie la simulation de glace marine dans un modèle de circulation océanique générale à faible résolution dans la baie d'Hudson et dans les eaux avoisinantes. La distribution et la durée de la glace marine correspondent bien aux valeurs climatologiques, bien que l'épaisseur de la glace soit sous-simulée comme c'est le cas dans d'autres travaux de modélisation. Dans la baie d'Hudson, la variation de l'epaisseur de la glace est dominée par le forçage atmosphérique, comme on peut le voir d'après la réponse symétrique de l'épaisseur de la glace suivant les scénarios de réchauffement et de refroidissement. Les flux de chaleur sous la glace jouent un rôle plus important dans le bassin de Foxe et la baie Baffin, où ils permettent une réduction des pertes de chaleur air-glace allant jusqu'à 40 pour cent, limitant ainsi l'épaisseur de la glace et la durée. Le flux de chaleur sous la glace diminue de 23 pour cent dans la région étudiée (baie d'Hudson, bassin de Foxe, baie Baffin et mer du Labrador) pour un refroidissement global de 3C et augmente de 9 pour cent pour un réchauffement global de 3C. On attribue cette réponse asymétrique à la réponse asymétrique de l'océan aux scénarios de refroidissement et de réchauffement. Dans la mesure où, comme l'indiquent ces résultats, la baie d'Hudson est dominée par le forçage atmosphérique plutôt que par la chaleur sous la glace, des modèles à faible résolution peuvent être utiles pour évaluer l'impact des changements. Cependant, la reconfiguration nécessaire de la grille du modèle atténue la crédibilité des résultats obtenus dans le Bassin de Foxe et le détroit d'Hudson. 相似文献
995.
A. ADRIAENS P. VENY F. ADAMS R. SPORKEN P. LOUETTE B. EARL H.
ZBAL K. A. YENER 《Archaeometry》1999,41(1):81-89
Nine powder samples originating from the archaeometallurgical she in Göltepe, southern central Turkey, have been analysed. Bulk analyses, using X-ray fluorescence and X-ruy photoelectron spectroscopy, and single particle analyses, using electron probe X-ray microanalysis, were carried out. The analyses were focused on determining the inorganic elemental composition of the samples and the distribution of particle types in the nine powder samples. In addition, the powder samples were classified on the basis of their elemental composition using multivariate techniques. The objective of this study was to characterize the powder samples and to establish an association with archaeological data from the site 相似文献
996.
Paul A. Roth 《History and theory》1999,38(2):249-263
Book reviewed in this article:
The Logic of Historical Explanation by Clayton Roberts 相似文献
The Logic of Historical Explanation by Clayton Roberts 相似文献
997.
998.
Barbara A. Moss 《The Journal of religious history》1999,23(1):108-127
African religious beliefs invaded Christian missions and provided the backdrop for interaction between African converts and women missionaries. African women came to missions not as tabulae rasae; their culture had stamped them with expectations and insights with which they imbibed and moulded the Christian message. They viewed religion as a resource. Their cultural expectations reinforced missionary promises and facilitated Christian conversion. As religious specialists women gained status, respect, social and economic security in pre-colonial society because they provided necessary and important services. These expectations lingered among African women at the missions. Thus, within patriarchal Christian denominations African women often exhibited an assertiveness which missionaries misunderstood and maligned. Mission conflicts were based on missionary attempts to make African women dependent upon their Christian spouses. This role was contradictory to African beliefs and Christian African needs. Differences were further exacerbated by gender discrimination within the church, which affected both European and African women, and colonialism, which provided the background for Christian occupation of the colony. Although familial obligations and cultural expectations were points of contention, motherhood, literacy, and leadership training provided meeting points of mutual concern for African women and missionaries. 相似文献
999.
Lynn A Blake 《Transactions (Institute of British Geographers : 1965)》1999,24(1):79-93
I deploy Michel Foucault's concepts of pastoral power and governmentality to investigate the material consequences of two very different visions of the governance of Native people in nineteenth-century British Columbia. This entails a consideration of these modalities of power, and of the usefulness of relocating them in a colonial context. But I also argue that the conceptions of order embedded within these two modalities of power bear the stamp of, and demonstrate, very distinctive cultural geographies. 相似文献
1000.
Joseph A. Rodriguez 《对极》1999,31(2):212-228
Regional transportation planning shaped minority activism in the mid-1960s. The Bay Area Rapid Transit (BART) system encouraged West Oakland activists to create a strong local identity. BART supporters valued regional mobility and blamed ghetto poverty on the inaccessibility of suburban jobs. Minority activists blamed BART for harming the ghetto poor by encouraging job migration to the suburbs, and for displacing residents. As compensation, they demanded that BART hire minority workers and increase relocation payments. While West Oakland activists largely failed to influence BART, the newly unified community did gain local control of schools and urban poverty programs. 相似文献