Stratification and water mass formation in the Arctic Ocean: some implications for the nutrient distribution   总被引：1，自引：1，他引：0  

Burt Rudels  Anne-Marie Larsson  Per-Ingvar Sehlstedt 《Polar research》1991,10(1):19-32

The mixing processes and the water formations (transformations) in the Arctic Ocean are reviewed and their influence on the stratification discussed. The relations between the stratification and the nutrient distribution are examined. The interactions between drifting sea ice and advected warmer and nutrient-rich waters favour an early biological activity. By contrast, in the central Arctic Ocean and over comparably deep shelf areas such as the northern Barents Sea, the possibilities for large productivity are more limited because of late melting, less nutrient supply, and in the central Arctic, less available light. The sedimentation of organic matter on the shelves and the remineralisation into cold, dense waters formed by brine rejection and draining off the shelves lead to a loss of nutrients to the deep waters, which must be compensated for by advection of nutrient rich waters to the Arctic Ocean.
Possible effects of a reduction of the river run-off on the stratification and the nutrient distribution are discussed.  相似文献   

Embracing postcolonial geographies: Contributions by Dame Evelyn Stokes to the development of postcolonial geography in New Zealand     

Anne-Marie d'Hauteserre 《New Zealand geographer》2005,61(2):102-109

Abstract: This paper acknowledges Dame Evelyn Stokes’ introduction of postcolonial critical analysis of Māori/Pākehā relationships before postcolonialism was established as a field of theoretical enquiry. The paper reviews research I have done on some of the issues faced by the Mashantucket Pequots in the wider context of the contribution Dame Evelyn Stokes was making to similar debates in New Zealand. She emphasized that Māori research and knowledge provide a different world view and that this world view needs to be taken into account in any geographical study of New Zealand. Only in this way will it be possible to avoid the continued marginalization of Māoris from nation building in their own country.  相似文献   

Seismic Microzonation: A Comparison between Geotechnical and Seismological Approaches in Pointe-à-Pitre (French West Indies)   总被引：1，自引：0，他引：1  

Benoit LeBrun  Anne-Marie Duval  Pierre-Yves Bard  Olivier Monge  Myriam Bour  Sylvain Vidal  Hubert Fabriol 《Bulletin of Earthquake Engineering》2004,2(1):27-50

Pointe-à-Pitre, the main city of Guadeloupe in the French West Indies, has on several occasions been partially destroyed by major historical earthquakes. Moreover, a post-seismic assessment of the damage from the 1985 Montserrat earthquake indicates that the town is prone to site effects. Consequently, from 1996 to 1998, BRGM conducted a seismic microzonation study based on geotechnical and geological data. At the same time, three seismological studies were being conducted – two based on earthquake recordings using a time-series analysis and the classical spectral ratio (CSR) method (CETE/LCPC and BRGM), and the third based on noise measurement at 400 points using the horizontal-to-vertical noise ratio (HVNR) method (CETE/LCPC). The objective of this paper is not to carry out a new microzonation study by taking into account all the results, but rather to show in what respects the results of these different methods are in agreement or not. A comparison of the results of the seismological studies with the geotechnical microzonation shows that they are in fairly good agreement, albeit with some discrepancies. The results indicate that the seismological methods and the geotechnical data are highly complementary and should be used together in compiling seismic transfer-function microzonation maps. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Book Reviews     

Anne-Marie de Grosbois 《Environmental Geology》2006,49(6):931-932

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Book reviews     

Anne-Marie de Grosbois 《Environmental Geology》2006,49(7):1079-1080

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Speciation and role of iron in cloud droplets at the puy de Dôme station     

Marius Parazols  Angela Marinoni  Pierre Amato  Otman Abida  Paolo Laj  Gilles Mailhot  Anne-Marie Delort  Zappoli Sergio 《Journal of Atmospheric Chemistry》2007,57(3):299-300

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Implications of biological and physical diversity for resilience and resistance patterns within Highly Dynamic River Systems     

Eric Tabacchi  Johannes Steiger  Dov Corenblit  Michael T. Monaghan  Anne-Marie Planty-Tabacchi 《Aquatic Sciences - Research Across Boundaries》2009,71(3):279-289

The structure and function of alluvial Highly Dynamic River Systems (HDRS) are driven by highly variable hydrological disturbance regimes, and alternate between resistant, metastable states and resilient, transitional states. These are in turn subject to influences of feedback loops within hydrogeomorphic and biological processes. Here we consider how resistance and resilience largely determine HDRS ecosystem trajectories and how these characteristics can be modified by natural and anthropogenic processes. We review the mechanisms by which biodiversity can affect both resistance and resilience and introduce a conceptual framework that incorporates some unique HDRS characteristics. We suggest that resilient and resistant patterns frequently coexist in the active tract of these river systems, and that this coexistance promotes the return of metastable states after major disturbances. In contrast, highly resistant and poorly resilient patterns dominate at their external boundaries. The loss of these natural dynamics resulting from direct and indirect human impacts causes deviations to resistance and resilience patterns and therefore to HDRS trajectory. We propose that understanding the role of interactions between biological and physical processes that control resistance and resilience is crucial for system restoration and management.  相似文献   

A dynamic and mechanistic model of PCB bioaccumulation in the European hake (Merluccius merluccius)   总被引：1，自引：0，他引：1  

Xavier Bodiguel  Olivier Maury  Capucine Mellon-Duval  Franois Roupsard  Anne-Marie Le Guellec  Vronique Loizeau 《Journal of Sea Research》2009,62(2-3):124

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Sensitivity of near-surface Tropical Instability Waves to submonthly wind forcing in the tropical Atlantic     

Gabriela Athi  Frdric Marin  Anne-Marie Treguier  Bernard Bourls  Catherine Guiavarc&#x;h 《Ocean Modelling》2009,30(4):241-255

This study demonstrates the sensitivity of the near-surface properties in the tropical Atlantic Ocean to the high-frequency of the winds in numerical simulations. At intra-seasonal timescales (2–50 days), two distinct period ranges dominate the variability in the upper ocean: periods between 2 and 20 days, which are essentially wind-forced and periods between 20 and 50 days, due mostly to Tropical Instability Waves (TIWs). Using a numerical model forced by different wind fields, it is shown that the characteristics of the intra-seasonal variability in the ocean surface mixed-layer are strongly dependent on the wind forcing. Submonthly winds are shown to force large variability in the upper ocean that can strikingly decrease the amplitude of the TIWs in the mixed-layer and their imprint on the horizontal distribution of sea surface temperatures. Wind products containing too much energy at submonthly periods thus prevent wind-forced simulations from reproducing a realistic surface signature of TIWs, when compared to satellite observations of sea surface temperature. In addition, submonthly wind variability may be responsible for part of the observed interannual variability of the TIW signature in the temperature. The impact of submonthly winds is strongest in the mixed-layer: beneath the mixed-layer, all simulations show similar characteristics of the TIWs.  相似文献   

An ERA40-based atmospheric forcing for global ocean circulation models     

Laurent Brodeau  Bernard Barnier  Anne-Marie Treguier  Thierry Penduff  Sergei Gulev 《Ocean Modelling》2010,31(3-4):88-104

We develop, calibrate and test a dataset intended to drive global ocean hindcasts simulations of the last five decades. This dataset provides surface meteorological variables needed to estimate air-sea fluxes and is built from 6-hourly surface atmospheric state variables of ERA40. We first compare the raw fields of ERA40 to the CORE.v1 dataset of Large and Yeager (2004), used here as a reference, and discuss our choice to use daily radiative fluxes and monthly precipitation products extracted from satellite data rather than their ERA40 counterparts. Both datasets lead to excessively high global imbalances of heat and freshwater fluxes when tested with a prescribed climatological sea surface temperature. After identifying unrealistic time discontinuities (induced by changes in the nature of assimilated observations) and obvious global and regional biases in ERA40 fields (by comparison to high quality observations), we propose a set of corrections. Tropical surface air humidity is decreased from 1979 onward, representation of Arctic surface air temperature is improved using recent observations and the wind is globally increased. These corrections lead to a significant decrease of the excessive positive global imbalance of heat. Radiation and precipitation fields are then submitted to a small adjustment (in zonal mean) that yields a near-zero global imbalance of heat and freshwater. A set of 47-year-long simulations is carried out with the coarse-resolution (2° × 2°) version of the NEMO OGCM to assess the sensitivity of the model to the proposed corrections. Model results show that each of the proposed correction contributes to improve the representation of central features of the global ocean circulation.  相似文献