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| Registros recuperados: 10 | |
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| Kienast, M.; Lehmann, M. F.; Timmermann, A.; Galbraith, E.; Bolliet, T.; Holboum, A.; Normandeau, C.; Laj, C.. |
| Sedimentary delta(15)N records from the oligotrophic western equatorial Pacific (WEP) off Mindanao show that late Holocene sedimentary delta(15)N is substantially lower than that of the early Holocene, following a gradual >3 parts per thousand decrease that occurred between 7 and 3 kyrs ago. Analyses of modem day nitrate isotope profiles from the same region indicate the sensitivity of the WEP N pools towards (1) the advection of (15)N-enriched nitrate from the Eastern Equatorial Pacific (EEP) by the North Equatorial Current (NEC) and the Mindanao Current in subsurface waters and, (2) at shallow depths, the input of new and (15)N-depleted nitrate through N, fixation. We suggest that the Holocene decrease in sedimentary delta(15)N reflects a diminished... |
| Tipo: Text |
Palavras-chave: Tropical Pacific; El Nino; Surface temperature; Fresh water; Nitrate; Mindanao; Ocean; Variability; Holocene; Seawater. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00207/31843/30257.pdf |
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| Radenac, Marie-helene; Dandonneau, Yves; Blanke, Bruno. |
| A Lagrangian analysis was applied to the outputs of a coupled physical-biogeochemical model to describe the redistribution of nitrate-rich and nitrate-poor surface water masses in the tropical Pacific throughout the major 1997 El Nino. The same tool was used to analyze the causes of nitrate changes along trajectories and to investigate the consequences of the slow nitrate uptake in the high nutrient low chlorophyll (HNLC) region during the growth phase of the event. Three patterns were identified during the drift of water masses. The first mechanism is well known along the equator: oligotrophic waters from the western Pacific are advected eastward and retain their oligotrophic properties along their drift. The second concerns the persistent upwelling in... |
| Tipo: Text |
Palavras-chave: Lagrangian analysis; El Nino; Tropical Pacific; Nitrate uptake. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-938.pdf |
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| Neira, C; Sellanes, J; Soto, A; Gutierrez, D; Gallardo, Va. |
| Quantitative surveys of metazoan meiofauna were carried out in an upwelling region off Central Chile (36 degreesS). During May 1997 and May 1998, coinciding with the onset and end of Fl Nino, five benthic stations (respectively 27, 34, 64, 88, and 120 m depth), from the middle of Concepcion Bay to the edge of the adjacent continental shelf, were sampled. The sedimentary organic matter biopolymeric fraction (proteins, carbohydrates and lipids) and chloroplastic pigments were also assessed. Total meiofauna abundance and biomass increased significantly between sampling dates at the mid-bay and inner shelf sites, from 1474 +/- 354 to 5035 +/- 291 individuals 10 cm(-2) and from 2618 +/- 332 to 5241 +/- 903 individuals 10 cm(-2), respectively. The relative... |
| Tipo: Text |
Palavras-chave: Chili central; El Niño; Méiofaune; Matière organique; Thioploca; Central Chile; El Nino; Meiofauna; Organic matter; Thioploca. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00322/43358/42857.pdf |
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| Valdivia, Corinne; Jette, Christian; Quiroz, Roberto; Gilles, Jere L.; Materer, Susan M.. |
| Production strategies pursued by households and individuals in a peasant community of the Bolivian Altiplano are shaped by access to resources, social networks and institutions, wealth, and the ability to develop urban rural linkages. In times of climatic stress such as the low rainfall of 1995, the household economic portfolio shifts to activities less vulnerable to climate. The ability to shift is conditioned by access to resources, social capital, stage in the life cycle and wealth. Atypology developed to understand how strategies take shape during a drought is used to evaluate access to information during el Nino (1997-98) and impacts on potato production in 1998-99. The relationship between diversification and use of climate forecasts (local and... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Climate Variability; El Nino; Coping Strategies; Rural Livelihoods; Climate Forecasts; Consumer/Household Economics; Environmental Economics and Policy. |
| Ano: 2002 |
URL: http://purl.umn.edu/92895 |
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| Bergeron, Nancy; Sedjo, Roger A.. |
| El Nino events are likely to affect maple syrup production since it is very sensitive to weather patterns. A statistically significant direct correlation has not been found in our preliminary analysis, however. This may be because many other factors affect production and because weather anomalies also occur in non-El Nino years. Few defensive activities are available to maple syrup producers to alleviate the negative impacts of weather anomalies on their production. Hence, the value of El Nino-Southern Oscillation (ENSO) forecasts to them is likely to be low, even if a clear correlation between productivity and ENSO events was eventually found. Overall, small welfare impacts of El Nino weather events are expected from their impact on the maple syrup... |
| Tipo: Working or Discussion Paper |
Palavras-chave: El Nino; Forests; Maple syrup; Economic welfare effects; Dieback; Resource /Energy Economics and Policy; D61; Q10; Q20; Q23; N5. |
| Ano: 1999 |
URL: http://purl.umn.edu/10671 |
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| Registros recuperados: 10 | |
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