Comparison of C and N stable isotope ratios between surface particulate organic matter and microphytoplankton in the Gulf of Lions (NW Mediterranean)     

Mireille Harmelin-Vivien  Véronique Loizeau  Capucine Mellon  Beatriz Beker  Denise Arlhac  Xavier Bodiguel  Franck Ferraton  Rachel Hermand  Xavier Philippon  Chantal Salen-Picard 《Continental Shelf Research》2008

Carbon and nitrogen stable isotope ratios of particulate organic matter (POM) in surface water and 63–200 μm-sized microphytoplankton collected at the fluorescence maximum were studied in four sites in the Gulf of Lions (NW Mediterranean), a marine area influenced by the Rhone River inputs, in May and November 2004. Some environmental (temperature, salinity) and biological (POM, Chlorophyll a and phaeopigments contents, phytoplankton biomass and composition) parameters were also analysed. Significantly different C and N isotopic signatures between surface water POM and microphytoplankton were recorded in all sites and seasons. Surface water POM presented systematically lower δ¹³C (∼4.2‰) and higher δ¹⁵N (∼2.8‰) values than those of microphytoplankton, due to a higher content of continental and detrital material. Seasonal variations were observed for all environmental and biological parameters, except salinity. Water temperature was lower in May than in November, the fluorescence maximum was located deeper and the Chlorophyll a content and the phytoplankton biomass were higher, along with low PON/Chl a ratio, corresponding to spring bloom conditions. At all sites and seasons, diatoms dominated the phytoplankton community in abundance, whereas dinoflagellate importance increased in autumn particularly in coastal sites. C and N isotopic signatures of phytoplankton did not vary with season. However, the δ¹⁵N of surface water POM was significantly higher in November than in May in all sites likely in relation to an increase in ¹⁵N/¹⁴N ratio of the Rhone River POM which influenced surface water in the Gulf of Lions. As it is important to determine true baseline values of primary producers for analysing marine food webs, this study demonstrated that C and N isotopic values of surface water POM cannot be used as phytoplankton proxy in coastal areas submitted to high river inputs.  相似文献   

Exploring typhoon variability over the mid-to-late Holocene: evidence of extreme coastal flooding from Kamikoshiki,Japan   总被引：1，自引：0，他引：1  

Jonathan D. Woodruff  Jeffrey P. Donnelly  Akiko Okusu 《Quaternary Science Reviews》2009,28(17-18):1774-1785

Sediment cores from two coastal lakes located on the island of Kamikoshiki in southwestern Japan (Lake Namakoike and Lake Kaiike) provide evidence for the response of a backbarrier beach system to episodic coastal inundation over the last 6400 years. Sub-bottom seismic surveys exhibit acoustically laminated, parallel to subparallel seismic reflectors, intermittently truncated by erosional unconformities. Sediment cores collected from targeted depocenters in both lakes contain finely laminated organic mud interbedded with coarse-grained units, with depths of coarse deposits concurrent with prominent seismic reflectors. The timing of the youngest deposit at Kamikoshiki correlates to the most recently documented breach in the barrier during a typhoon in 1951 AD. Assuming that this modern deposit provides an analog for identifying past events, paleo-typhoons may be reconstructed from layers exhibiting an increase in grain-size, a break in fine-scale stratigraphy, and elevated Sr concentrations.Periods of barrier breaching are concurrent with an increase in El Niño frequency, indicating that the El Niño/Southern Oscillation has potentially played a key role in governing typhoon variability during the mid-to-late Holocene. An inverse correlation is observed between tropical cyclone reconstructions from the western North Atlantic and the Kamikoshiki site, which may indicate an oscillating pattern in tropical cyclone activity between the western Northern Atlantic and the western North Pacific, or at least between the western Northern Atlantic and regions encompassing southern Japan. The two kamikaze typhoons which contributed to the failed Mongol invasions of Japan in 1274 AD and 1281 AD occur during a period with more frequent marine-sourced deposition at the site, suggesting that the events took place during a period of greater regional typhoon activity.  相似文献   

Seasonal and spatial variation in groundwater quality along the hillslope of an agricultural research catchment (Western France)     

Matthieu Rouxel  Jérôme Molénat  Laurent Ruiz  Cédric Legout  Mickaël Faucheux  Chantal Gascuel‐Odoux 《水文研究》2011,25(6):831-841

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In situ biomonitoring of caged, juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Lower Duwamish Waterway     

Kelley MA  Gillespie A  Zhou GD  Zhang S  Meador JP  Duncan B  Donnelly KC  McDonald TJ 《Marine pollution bulletin》2011,62(11):2520-2532

Contaminated sediments may have wide-ranging impacts on human and ecological health. A series of in situ caged exposure studies using juvenile Chinook salmon was conducted in the Lower Duwamish Waterway (LDW). Chemical analysis of sediment, water, and fish tissue were completed. Additionally, in 2004, DNA adducts in hepatic and gill tissues were measured. Gills contained significantly higher DNA adducts at stations B2 and B4, prompting further analysis of gills in 2006 and 2007. Fluorescent aromatic compounds (FACs) in bile, and CYP1A1 in hepatic tissue were also measured during 2006 and 2007, respectively. FACs in field-caged fish were comparable or significantly higher than wild-caught fish LDW fish and significantly higher than lab fish after only 8-10 days, demonstrating the equivalency of exposure to that of migrating salmon. Furthermore, selected biomarkers appear to be capable of detecting spikes in contamination between sampling years, emphasizing the need for multiple year data collection.  相似文献   

    

Richard F. Donnelly 《Solar physics》1998,178(2):438

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Spatial modelling of discharge and concentration of matter along a stream network     

Chantal Gascuel-Odoux 《Comptes Rendus Geoscience》2006,338(9):585-586

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Quaternary ice sheet–ocean interactions and landscape responses     

Benjamin P. Horton  Antony J. Long  Jeffrey P. Donnelly 《Quaternary Science Reviews》2009,28(17-18):1570-1572

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The X-ray and extreme ultraviolet radiation of the August 28, 1966 proton flare as deduced from sudden ionospheric disturbance data     

R. F. Donnelly 《Solar physics》1968,5(1):123-126

Ionospheric data show that a very large burst of extreme ultraviolet radiation of about 7 ergs cm^?2 sec^?1 above the earth's atmosphere occurred during the proton flare of August 28, 1966. The time dependence of this burst agrees closely with the 8800 and 10700 MHz solar radio bursts and does not agree with solar radio bursts at frequencies less than 2800 MHz. The soft X-ray enhancement deduced from ionospheric data peaked about 4 min after the EUV burst.  相似文献   

River discharge to the Baltic Sea in a future climate   总被引：1，自引：0，他引：1  

Chantal Donnelly  Wei Yang  Joel Dahné 《Climatic change》2014,122(1-2):157-170

This study reports on new projections of discharge to the Baltic Sea given possible realisations of future climate and uncertainties regarding these projections. A high-resolution, pan-Baltic application of the Hydrological Predictions for the Environment (HYPE) model was used to make transient simulations of discharge to the Baltic Sea for a mini-ensemble of climate projections representing two high emissions scenarios. The biases in precipitation and temperature adherent to climate models were adjusted using a Distribution Based Scaling (DBS) approach. As well as the climate projection uncertainty, this study considers uncertainties in the bias-correction and hydrological modelling. While the results indicate that the cumulative discharge to the Baltic Sea for 2071 to 2100, as compared to 1971 to 2000, is likely to increase, the uncertainties quantified from the hydrological model and the bias-correction method show that even with a state-of-the-art methodology, the combined uncertainties from the climate model, bias-correction and impact model make it difficult to draw conclusions about the magnitude of change. It is therefore urged that as well as climate model and scenario uncertainty, the uncertainties in the bias-correction methodology and the impact model are also taken into account when conducting climate change impact studies.  相似文献   

A spatio-temporal ontology for geographic information integration     

Thomas Bittner  Maureen Donnelly  Barry Smith 《International journal of geographical information science》2013,27(6):765-798

This paper presents an axiomatic formalization of a theory of top-level relations between three categories of entities: individuals, universals, and collections. We deal with a variety of relations between entities in these categories, including the sub-universal relation among universals and the parthood relation among individuals, as well as cross-categorial relations such as instantiation and membership. We show that an adequate understanding of the formal properties of such relations – in particular their behavior with respect to time – is critical for geographic information processing.

The axiomatic theory is developed using Isabelle, a computational system for implementing logical formalisms. All proofs are computer verified and the computational representation of the theory is available online.  相似文献