La niña

Is El Niño something new and unusual in the Earth's climate? No. El Niño has been occurring at least since people started putting thermometers in the ocean around the middle of the nineteenth century. Moreover, archived documents left by the Spanish colonists in Peru confirm that El Niño impacts such as occur now (flooding, marine life disturbances, etc.) have been felt in Peru ever since the first conquistador (Francisco Pizarro) set foot there in the early 16th century. And, as far as we can tell from paleo-climatic indicators such as geological evidence & tree rings, El Niño has been occurring for at least thousands of years, probably much as it has during this century. It will probably continue to occur as long as our climate system works the way it has since the most recent ice sheets of the late pleistocene receded (i.e., needing to get rid of excess tropical heat as explained in the question Does El Niño play a special role in Nature?).

The restinga de Maricá has twelve species of mammals identified. All species are in common with the Atlantic Forest. The ones we studied the water balance had no adaptation to salt concentration. The restinga has four major type of macrohabitat that are determined by the interaction between soil and microclimate. There some variation in mammal distribution and abundance due to habitat variation at both meso and micro scales. The variation was the cause in the variance in mammal density at each collecting place with no discernible border effect: where humidity is higher there was higher mammal diversity and populations. A population study was carried out during five years showing an increase in abundance in an La Niña year. Only one in seven species showed no microhabitat preferences. This one had its distribution determined by abundance of alimentary resources. Some methodological problems are discussed.

The El Niño Southern Oscillation (ENSO) is a major source of interannual climate variability. ENSO life cycles and the associated teleconnections evolve over multiple years at a global scale. This analysis is the first attempt to characterize the structure of the risk posed by trans-Pacific ENSO teleconnections to crop production in the greater Pacific Basin region. In this analysis we identify the large-scale atmospheric dynamics of ENSO teleconnections that affect heat and moisture stress during the growing seasons of maize, wheat and soy. We propose a coherent framework for understanding how trans-Pacific ENSO teleconnections pose a correlated risk to crop yields in major agricultural belts of the Americas, Australia and China over the course of an ENSO life cycle by using observations and a multi-model ensemble of climate anomalies during crop flowering seasons. Trans-Pacific ENSO teleconnections are often (but not always) offsetting between major producing regions in the Americas and those in northern China or Australia. El Niños tend to create good maize and soybean growing conditions in the US and southeast South America, but poor growing conditions in northern China, southern Mexico and the Cerrado in Brazil. The opposite is true during La Niña. Wheat growing conditions in southeast South America generally have the opposite sign of those in Australia. Furthermore, multi-year La Niñas can force multi-year growing season anomalies in Argentina and Australia. Most ENSO teleconnections relevant for crop flowering seasons are the result of a single trans-Pacific circulation anomaly that develops in boreal summer and persists through the following spring. During the late summer and early fall of a developing ENSO event, the tropical Pacific forces an atmospheric anomaly in the northern midlatitudes that spans the Pacific from northern China to North America and in the southern midlatitudes from Australia to southeast South America. This anomaly directly links the soybean and maize growing seasons of the US, Mexico and China and the wheat growing seasons of Argentina, southern Brazil and Australia. The ENSO event peaks in boreal winter, when the atmospheric circulation anomalies intensify and affect maize and soybeans in southeast South America. As the event decays, the ENSO-induced circulation anomalies persist through the wheat flowering seasons in China and the US.

El presente estudio evaluó la incidencia de los parámetros abióticos en la abundancia del fitoplancton a profundidades estándares de la columna de agua, en una estación ubicada 10 millas costa afuera frente a Puerto López durante los años 2011 y 2012. Para lo cual se realizó
la identificación y cuantificación del fitoplancton, así como determinación de temperatura y nutrientes inorgánicos. El fitoplancton presentó variaciones en la abundancia y distribución, siendo sus valores inferiores a lo establecido como promedio para esta zona, con mayor actividad celular entre la superficie y 10 m de profundidad, siendo Nitzschia longissima y Cylindrotheca closterium, las que tipificaron a la comunidad en función de las abundancias registradas. Los resultados obtenidos fueron validados estadísticamente mediante: Prueba no paramétrica (Kruskal Wallis), análisis de correspondencia canónica y rangos de correlación de Spearman. Las relaciones entre el fitoplancton y las condiciones oceanográficas determinaron que las siguientes especies: Dactyliosolen fragilissimus, Pseudo-nitzschia complejo seriata y Leptocylindrus danicus tuvieron una correlación fuerte con los nutrientes (nitrito, nitrato y silicato), siendo el segundo y tercer
nutriente quienes intervinieron positivamente en la concentración de L. danicus durante 2011, mientras que para 2012 Cylindrotheca closterium y Pseudo-nitzschia complejo seriata tuvieron correlaciones fuertes e inversas con la temperatura y directa con los nutrientes, es decir, las
variables ambientales influyeron en la abundancia del fitoplanctónica durante la estación seca.

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The aim of this paper was to verify whether there is a correlation between rainfall conditions that occurred in Azul, Buenos Aires (Lat 36°45' S; 59°57' W and Long altitude 137 m), between 1950 2015, and thermal anomalies generated in ENSO episodes in its warm phases El Niño (EN) and cold La Niña (LN), using a monthly series and annual rainfall. The annual rainfall showed a slight positive trend in the case of EN and below the central tendency for LN; however, these differences were not significant at 5% probability. In the monthly scale very low values were found in the Pearson Index, where only for the process LN, and June (IP 0.5692), the linear relationship and t-Student analysis were slightly significant, 5%. Therefore, the existence of a change in the local rainfall regime in the years in which this process was present cannot be confirmed.