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The coral communities and coral reefs of the Galapagos Marine Reserve support tens of thousands of species, including many rare and endemic species. Reef-building corals are sensitive to elevated temperatures, which have been linked to coral bleaching (loss of symbiotic zooxanthellae) and therefore their distribution around the islands has been strongly affected by extreme climatic events over the last 30 years. Following the 1982–3 El Niño-Southern Oscillation event, coral cover was reduced by 95 %, with further mortality in the 1997–8 event. Although there has been significant recovery of the communities in recent years, there is concern that by 2100 the global climate system and sea surface temperatures will warm by between 1.4° and 5.8°C, which could result in 100% mortality of Galapagos corals. This paper reports a temperature and depth bioclimatic envelope (or niche) model of potential coral distribution, developed using an historical analysis of monthly sea surface temperatures, derived from the NOAA AVHRR over the period 1985–2001, and a near-shore bathymetry data set derived from Shuttle Radar Topography Mission digital topographic data integrated with ship-based depth sounding surveys and digitised hydrographic maps. The model was validated against known coral community and coral reef localities. Application of the model can support the identification of potential new areas where conditions for coral growth are favourable and enable predictions of the effects of future climate change.

The behavior of an index based on the difference of atmospheric pressure between Darwin and Paita (IDP) was analyzed, as an indicator of the effects of El Niño and La Niña in the Northern Humboldt Current Ecosystem (NHCE). The temporal variation of IDP at monthly scale had a good correlation with the Southern Oscillation Index (SOI). Additionally, the maximum cross correlation between IDP and AN3.4 was found at a lag of -3, which could allow to use the IDP to simulate the AN3.4. The behavior of IDP obeys to the complex interaction between the atmospheric system of the region and the Equatorial Pacific. Se analizó el comportamiento de un índice basado en la diferencia de anomalías de presiones atmosféricas entre Darwin y Paita (IDP), como un indicador de los efectos de El Niño y La Niña frente a la costa peruana, en el Norte del Ecosistema de la Corriente de Humboldt (NECH). La variación temporal a escala mensual del IDP tuvo buena correlación (r = 0,68; p

Stability analysis of the relationship between the Southern Oscillation and rainfall in South America Abstract The Southern Oscillation (SO) is a significant factor of the interannual rainfall variability in South America, particularly in the northern portion of the continent; the coastal sector of northern Peru; Northeast Brazil; the southern part of the Paraná basin; and central Chile. Using sea level pressure at Darwin as an index for the SO, it is determined that its relationship with rainfall in those regions has varied significantly during the past hundred years. The possibility that these fluctuations reflect changes in the functioning of the SO is not excluded. This situation limits considerably the potential of this SO index in statistical models of climate forecasting in South America, and makes uncertain the extrapolation to the past of relationships between the SO and the interannual climate variability, observed during the present., Analyse de la stabilité de la relation entre l'Oscillation du Sud et la précipitation en Amérique du Sud Résumé L' Oscillation du Sud (OS) est un facteur important forçant la variabilité interannuelle de la precipitation en Amérique du Sud, notamment dans le secteur nord du continent, dans la région côtière du nord du Pérou, dans le nord-est brésilien, dans le bassin du fleuve Parana, et dans le Chili central. En utilisant la pression à Darwin comme un indice de 1' OS, un changement de la relation entre celle-ci et la précipitation est observé au cours du dernier siècle. Il est possible que ces fluctuations mettent en évidence des changements dans le fonctionnement de 1' OS. D'une part, cette situation limite considérablement l'utilisation de cet indice de 1' OS dans des modèles statistiques de prévision climatique. D' autre part, ce fait introduit un certain degré d'incertitude dans les études basées sur l'extrapolation de relations actuelles OS-variabilité climatique pour l' interprétation du passé lointain., Resumen La Oscilación del Sur (OS) es un factor significativo de la variabilidad interanual de la precipitación en América del Sur, particularmente en el sector norte del continente; en la región costera del norte de Perú; en el nordeste brasileño; en la cuenca del río Paraná; y en Chile central. Utilizando la presión en Darwin como un índice de la OS, se determina que su relación con la precipitación en esas regiones ha cambiado significativamente a lo largo de los últimos cien años. No se excluye la posibilidad que tales fluctuaciones reflejen cambios en el funcionamiento de la OS. Esta situación limita considerablemente la utilización de este índice de la OS en modelos estadísticos de pronóstico climático y añade un grado adicional de incertidumbre a las extrapolaciones hacia el pasado remoto de las relaciones regionales actuales entre la OS y la variabilidad climática interanual., Aceituno Patricio, Montecinos Aldo. Análisis de la estabilidad de la relación entre la Oscilación del Sur y la precipitación en América del Sur. In: Bulletin de l'Institut Français d'Études Andines, tome 22, N°1, 1993. Enregistrements du phénomène El Niño et d’événements ENSO en Amérique du Sud. pp. 53-64.