Oceanographic events during el nino

El Ni?o events, the most spectacular instances of interannual variability in the ocean, have profound consequences for climate and the ocean ecosystem. The 1982-1983 El Ni?o is perhaps the strongest in this century. El Ni?o events usually have followed a predictable pattern, but the recent event differs markedly. The physical oceanography of this El Ni?o is described and compared with that of earlier events.     

Climatic anomalies in the tropical pacific ocean and corn yields in the United States

The association between climatic anomalies in the tropical Pacific Ocean, often called El Ni?o events, and annual corn production in the United States was investigated. Temperature and atmospheric pressure in parts of the United States have been correlated with El Ni?o events. This research suggests that in years in which an El Ni?o event causes surface temperatures in the tropical Pacific to become warmer than normal, there is a higher probability of an above-average corn crop in the United States. For years when sea surface temperatures are average or cool, no significant association is observed.     

Atmospheric carbon dioxide, the southern oscillation, and the weak 1975 el nino

The observed rate of change of the atmospheric carbon dioxide concentration at the South Pole, Fanning Island, Hawaii, and ocean weather station P correlates with an index of the southern oscillation and with El Ni?o occurrences. There are changes at all four stations that seem to be in response to the weak 1975 El Ni?o. Thus, even poorly developed El Ni?o events may affect the atmospheric carbon dioxide concentration.     

Zonal winds in the central equatorial pacific and el nino

Easterly trade winds from near-equatorial islands in the central Pacific weakened before each El Ni?o between 1950 and 1978, except for the 1963 El Ni?o. The weakening of the easterlies and their later collapse did not occur uniformly over several months, but rather through a series of strong westerly wind bursts lasting 1 to 3 weeks. The bursts may force equatorial Kelvin waves in the ocean that can both initiate and sustain the sea surface warming characteristics of El Ni?o events.     

Unraveling the mystery of Indian monsoon failure during El Niño

The 132-year historical rainfall record reveals that severe droughts in India have always been accompanied by El Ni?o events. Yet El Ni?o events have not always produced severe droughts. We show that El Ni?o events with the warmest sea surface temperature (SST) anomalies in the central equatorial Pacific are more effective in focusing drought-producing subsidence over India than events with the warmest SSTs in the eastern equatorial Pacific. The physical basis for such different impacts is established using atmospheric general circulation model experiments forced with idealized tropical Pacific warmings. These findings have important implications for Indian monsoon forecasting.     

厄尔尼诺/拉尼娜事件对区域气温的影响与预测——以沈阳地区为例

利用1961—2015年国家气象信息中心沈阳站的日平均气温资料、美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration,NOAA）提供的多变量ENSO指数（multivariate ENSO index,MEI）资料等,在分析沈阳地区气温月际变化的基础上,结合厄尔尼诺/拉尼娜事件对其影响特征,利用线性倾向估计和非线性自回归（nonlinear auto regressive models with exogenous inputs,NARX）神经网络模型分别对沈阳地区2011—2015年的气温进行预测。结果表明,1961—2015年共计660个月中,沈阳地区11月—3月气温的变异系数在20%以上,远大于其他月份。1961—2015年的厄尔尼诺/拉尼娜事件往往在秋冬季达到最大强度,或为导致沈阳地区11月—3月气温变异增强的原因之一。厄尔尼诺事件结束之后的春季,沈阳地区气温偏低的概率逾70%。沈阳地区气温随MEI变化的线性倾向值为0.98,决定系数为0.98且通过了0.01的可信度检验。利用MEI对沈阳地区的气温进行同期和时滞预测,NARX的预测结果均优于一元线性回归模型。当气温滞后MEI16个月时,两者的相关系数达到最大且通过了0.01的显著性检验,此时回归模型预测的相关系数为0.59,较同期预测提升了79%;NARX预测的均方误差（mean-square error,MSE）为0.49,较同期预测降低了36%,相关系数为0.86,较同期预测提升了8%。     

A theory for el nino and the southern oscillation

A coupled atmosphere-ocean model is presented for El Ni?o and the Southern Oscillation that reproduces its major features, including its recurrence at irregular intervals. The interannual El Ni?o-Southern Oscillation cycle is maintained by deterministic interactions in the tropical Pacific region. Ocean dynamics alter sea-surface temperature, changing the atmospheric heating; the resulting changes in surface wind alter the ocean dynamics. Annually varying mean conditions largely determine the spatial pattern and temporal evolution of El Ni?o events.     

Impacts of a global climate cycle on population dynamics of a migratory songbird

Progress toward understanding factors that limit abundances of migratory birds, including climate change, has been difficult because these species move between diverse locations, often on different continents. For black-throated blue warblers (Dendroica caerulescens), demographic rates in both tropical winter quarters and north temperate breeding grounds varied with fluctuations in the El Ni?o Southern Oscillation. Adult survival and fecundity were lower in El Ni?o years and higher in La Ni?a years. Fecundity, in turn, was positively correlated with subsequent recruitment of new individuals into winter and breeding populations. These findings demonstrate that migratory birds can be affected by shifts in global climate patterns and emphasize the need to know how events throughout the annual cycle interact to determine population size.     

Satellite observations of the 1982-1983 el nino along the u.s. Pacific coast

Satellite infrared temperature images illustrate several effects of the 1982-1983 El Ni?o: warm sea-surface temperatures with the greatest anomalies near the coast, weakened coastal upwelling, and changes in surface circulation patterns. Phytoplankton pigment images from the Coastal Zone Color Scanner indicate reduced productivity during El Ni?o, apparently related to the weakened coastal upwelling The satellite images provide direct evidence of mesoscale changes associated with the oceanwide El Ni?o event.     

Breeding patterns of galapagos penguins as an indicator of oceanographic conditions

Surface water changes associated with El Ni?o have been known to affect deleteriously top carnivores along coastal South America. Data on the breeding strategies of Galápagos penguins and other seabirds indicate that the biological effects of El Ni?o extend much farther west. The breeding biology of these seabirds is adapted to frequent changes in productivity which are associated with El Ni?o.     

The possible link between net surface heating and el nino

Three diagnostic analyses are described which strongly suggest the importance of local net surface heating in the life history of the large-scale, air-sea phenomenon centered in the eastern tropical Pacific Ocean, commonly called El Ni?o. These analyses rely upon monthly marine weather summaries for the period 1957 to 1976. In the first, correlations and coherence spectra were calculated which show a strong link between the net surface heat flux and sea-surface temperature variations over the eastern equatorial Pacific. The second analysis, also based upon the use of coherence spectra, indicates a sea temperature precursor in the eastern ocean near 25 degrees S which precedes sea temperature changes near the El Ni?o focus near 5 degrees S. Since the link between the two regions would require ocean advective velocities that appear to be unreasonably large, this analysis also suggests the importance of atmospheric forcing through the surface heat flux. In the third analysis a proxy variable is described that seems to be a reasonable indicator of the overall effect of ocean dynamics on the temperature of the El Ni?o core region. A composite analysis of the four El Ni?o events of 1957, 1965, 1972, and 1976 suggests that local surface heating is important during the early part of an event, whereas dynamical factors dominate later.     

ENSO as an integrating concept in earth science

The El Ni?o-Southern Oscillation (ENSO) cycle of alternating warm El Ni?o and cold La Ni?a events is the dominant year-to-year climate signal on Earth. ENSO originates in the tropical Pacific through interactions between the ocean and the atmosphere, but its environmental and socioeconomic impacts are felt worldwide. Spurred on by the powerful 1997-1998 El Ni?o, efforts to understand the causes and consequences of ENSO have greatly expanded in the past few years. These efforts reveal the breadth of ENSO's influence on the Earth system and the potential to exploit its predictability for societal benefit. However, many intertwined issues regarding ENSO dynamics, impacts, forecasting, and applications remain unresolved. Research to address these issues will not only lead to progress across a broad range of scientific disciplines but also provide an opportunity to educate the public and policy makers about the importance of climate variability and change in the modern world.     

Deep current measurements suggest long waves in the eastern equatorial pacific

During the 1975 El Ni?o expedition an array of conventional and electric field type near-bottom current recorders was deployed at the equator 300 kilometers west of the Galápagos Islands. While hydrographic observations were indicating El Ni?o activity off the South American coast, the current meters recorded an oscillation with a 25-day period, a wavelength of about 1000 kilometers, and an amplitude of 0.04 meter per second propagating westward at approximately 0.5 meter per second. These characteristics agree with theoretical models of a first-mode baroclinic Rossby wave trapped at the equator.     

Elimination of two reef-building hydrocorals following the 1982-83 el nino warming event

One probable extinction and one range reduction of eastern Pacific reef-building hydrocoral (Millepora) species mark the first documented cases of species eliminations resulting from the worldwide 1980s coral reef bleaching events. Two of 12 Panamanian coral species were eliminated suddenly from their former ranges by prolonged high sea temperatures during the 1982-83 El Ni?o-Southern Oscillation event. Three conditions contributed to their demise: high sensitivity to sea warming, populations confined to a small geographic area, and bathymetric restriction to the euphotic zone (相似文献   

CLIMATE PREDICTION: Second Thoughts on Skill Of El Nino Predictions

A few years' perspective on the 1997-98 El Ni?o and a toughening of standards has dropped model forecast performance from spectacular to encouraging; some critics don't even give the models a passing grade. According to an analysis published in the September issue of the Bulletin of the American Meteorological Society, the sophisticated models did a poor job of predicting the 1997-98 El Ni?o's full course; in fact, they did no better than a rudimentary model that can run on a desktop. Others won't go that far but agree that the models' reputation needs to be taken down a notch or two.     

Predicting and observing el nino

In October 1974 the occurrence of a weak El Ni?o event was predicted for early 1975 on the basis of the southern oscillation index. An expedition was organized to observe the event in the waters off Peru and Ecuador during two cruises in order to study its occurrence and its development with time. During the first cruise a massive transgression of warm low salinity water across the equator to 4 degrees S was observed, as well as a depression of the thermocline along the equator and off the coast of South America, indicating the start of El Ni?o development. During the second cruise the oceanographic situation had changed and conditions were returning to normal.     

Satellite color observations of the phytoplankton distribution in the eastern equatorial pacific during the 1982-1983. El nino

Dramatic changes in the patterns of satellite-derived pigment concentrations around the Galápagos Islands during February and March 1983 are associated with unusual oceanographic conditions observed during the 1982-1983 El Ni?o. The redistribution of food resources might have contributed to the reproductive failure of seabirds and marine mammals on these islands during this El Ni?o.     

Peru coastal currents during el nino: 1976 and 1982

Year-long measurements of subsurface current and temperature on Peru's continental shelf included the onset of El Ni?o in 1976 and 1982. The Peru Coastal Undercurrent more than doubled in speed and advected anomalously warm water poleward. El Ni?o began in different seasons in 1976 and 1982, but the current and temperature responses were very similar. Acceleration of poleward flow at 10 degrees S occurred several days after sea level rose at the Galápagos Islands in October 1982, suggesting the onset of El Ni?o propagated as a Kelvin wave.     

Meteorological aspects of the el nino/southern oscillation

The single most prominent signal in year-to-year climate variability is the Southern Oscillation, which is associated with fluctuations in atmospheric pressure at sea level in the tropics, monsoon rainfall, and wintertime circulation over North America and other parts of the extratropics. Although meteorologists have known about the Southern Oscillation for more than a half-century, its relation to the oceanic El Ni?o phenomenon was not recognized until the late 1960's, and a theoretical understanding of these relations has begun to emerge only during the past few years. The past 18 months have been characterized by what is probably the most pronounced and certainly the best-documented El Ni?o/Southern Oscillation episode of the past century. In this review meteorological aspects of the time history of the 1982-1983 episode are described and compared with a composite based on six previous events between 1950 and 1975, and the impact of these new observations on theoretical interpretations of the event is discussed.