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1.
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. 相似文献
2.
Observations of the 1982-1983 El Ni?o make it possible to relate the anomalous ocean conditions to specific biological responses. In October 1982 upwelling ecosystems in the eastern equatorial Pacific began a series of transitions from the normal highly productive condition to greatly reduced productivity. The highly productive condition had returned by July 1983. Nutrients, phytoplankton biomass, and primary productivity are clearly regulated by the physical changes of El Ni?o. Evidence from 1982 and 1983 also suggests effects on higher organisms such as fish, seabirds, and marine mammals, but several more years of observation are required to accurately determine the magnitude of the consequences on these higher trophic levels. 相似文献
3.
Fiedler PC 《Science (New York, N.Y.)》1984,224(4654):1251-1254
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. 相似文献
4.
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. 相似文献
5.
Bacastow RB Adams JA Keeling CD Moss DJ Whorf TP Wong CS 《Science (New York, N.Y.)》1980,210(4465):66-68
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. 相似文献
6.
Barnett T Graham N Cane M Zebiak S Dolan S O'brien J Legler D 《Science (New York, N.Y.)》1988,241(4862):192-196
Three different classes of numerical models successfully predicted the occurrence of the El Ni?o of 1986-87 at lead times of 3 to 9 months. Although the magnitude and timing of predicted ocean surface temperatures were not perfect, these results suggest that routine prediction of moderate to lare El Ni?o events is feasible. The key to the success of the models lies in recognizing or simulating the low-frequency, large-scale changes in the tropical ocean-atmosphere system that give rise to El Ni?o events. 相似文献
7.
A theory for el nino and the southern oscillation 总被引：1，自引：0，他引：1
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. 相似文献
8.
Oceanographic events during el nino 总被引：1，自引：0，他引：1
Cane MA 《Science (New York, N.Y.)》1983,222(4629):1189-1195
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. 相似文献
9.
The breeding chronology and reproductive attempts of the seabird community on Christmas Island in the central Pacific Ocean (2 degrees N, 157 degrees W) were interrupted by the 1982-1983 El Ni?o Southern Oscillation. The resultant reproductive failure and disappearance of the entire seabird community of this equatorial atoll represents the most dramatic interruption on record of a seabird community located distant from coastal upwelling. Our data indicate the effect that the abiotic and biotic aspects of a global atmospheric-oceanic anomaly have on marine birds. The 1982-1983 El Ni?o Southern Oscillation provides an example of selective pressures and a natural experiment in the study of vertebrate population dynamics. 相似文献
10.
A major change in the community structure of the dominant epibenthic megafauna was observed at 4100 meters depth in the northeast Pacific and was synchronous to a major El Ni?o/La Ni?a event that occurred between 1997 and 1999. Photographic abundance estimates of epibenthic megafauna from 1989 to 2002 show that two taxa decreased in abundance after 1998 by 2 to 3 orders of magnitude, whereas several other species increased in abundance by 1 to 2 orders of magnitude. These faunal changes are correlated to climate fluctuations dominated by El Ni?o/La Ni?a. Megafauna even in remote marine areas appear to be affected by contemporary climatic fluctuations. Such faunal changes highlight the importance of an adequate temporal perspective in describing biodiversity, ecology, and anthropogenic impacts in deep-sea communities. 相似文献
11.
Wolff C Haug GH Timmermann A Sinninghe Damsté JS Brauer A Sigman DM Cane MA Verschuren D 《Science (New York, N.Y.)》2011,333(6043):743-747
Interannual rainfall variations in equatorial East Africa are tightly linked to the El Ni?o Southern Oscillation (ENSO), with more rain and flooding during El Ni?o and droughts in La Ni?a years, both having severe impacts on human habitation and food security. Here we report evidence from an annually laminated lake sediment record from southeastern Kenya for interannual to centennial-scale changes in ENSO-related rainfall variability during the last three millennia and for reductions in both the mean rate and the variability of rainfall in East Africa during the Last Glacial period. Climate model simulations support forward extrapolation from these lake sediment data that future warming will intensify the interannual variability of East Africa's rainfall. 相似文献
12.
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. 相似文献
13.
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. 相似文献
14.
Weare BC 《Science (New York, N.Y.)》1983,221(4614):947-949
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. 相似文献
15.
Unraveling the mystery of Indian monsoon failure during El Niño 总被引：1，自引：0，他引：1
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. 相似文献
16.
Smith RL 《Science (New York, N.Y.)》1983,221(4618):1397-1399
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. 相似文献
17.
Saether BE 《Science (New York, N.Y.)》2000,288(5473):1975-1976
There has been increasing concern over the decline in many migratory bird species. As Saether discusses in his Perspective, evidence is accumulating (Sillett et al.) that climate change resulting from the El Ni?o Southern Oscillation affects both the survival rate of adult birds at tropical wintering sites and their reproductive rate at summer breeding grounds in the Northern Hemisphere. 相似文献
18.
Biospheric primary production during an ENSO transition 总被引：3，自引：0，他引：3
Behrenfeld MJ Randerson JT McClain CR Feldman GC Los SO Tucker CJ Falkowski PG Field CB Frouin R Esaias WE Kolber DD Pollack NH 《Science (New York, N.Y.)》2001,291(5513):2594-2597
The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) provides global monthly measurements of both oceanic phytoplankton chlorophyll biomass and light harvesting by land plants. These measurements allowed the comparison of simultaneous ocean and land net primary production (NPP) responses to a major El Ni?o to La Ni?a transition. Between September 1997 and August 2000, biospheric NPP varied by 6 petagrams of carbon per year (from 111 to 117 petagrams of carbon per year). Increases in ocean NPP were pronounced in tropical regions where El Ni?o-Southern Oscillation (ENSO) impacts on upwelling and nutrient availability were greatest. Globally, land NPP did not exhibit a clear ENSO response, although regional changes were substantial. 相似文献
19.
The source of irregularity in El Ni?o, the large interannual climate variation of the Pacific ocean-atmosphere system, has remained elusive. Results from an El Ni?o model exhibit transition to chaos through a series of frequency-locked steps created by nonlinear resonance with the Earth's annual cycle. The overlapping of these resonances leads to the chaotic behavior. This transition scenario explains a number of climate model results and produces spectral characteristics consistent with currently available data. 相似文献
20.
鲐鱼(Scomber japonicus)是中上层经济鱼类,也是我国近海重要的捕捞对象,其资源分布受不同尺度气候和海洋环境变化的显著影响。本文根据2005-2016年7-9月中国远洋渔业数据中心提供的我国东海鲐鱼捕捞数据,结合关键因子海表面温度(sea surface temperature,SST),计算各年鲐鱼渔场经纬度重心,量化鲐鱼渔场重心的时空变化。进一步分析了捕捞努力量在经度、纬度以及SST上的分布规律,并基于聚类法筛选出代表年份评估异常气候事件对鲐鱼渔场内SST及渔场重心时空分布的影响。研究结果显示,鲐鱼渔场重心具有显著的年际和月间变化,7-9月渔场逐渐向东北方向移动,且主要分布在SST为25~28°C范围内。聚类分析将各月份渔场重心分为四类,其中2007和2015年渔场分布具有显著差异。此外,鲐鱼渔场内SST与尼诺指数具有显著的正相关关系,且代表年份2007和2015年分别对应拉尼娜事件和厄尔尼诺事件,当拉尼娜事件发生时,渔场内SST上升,渔场重心逐渐北移;而厄尔尼诺事件发生时,渔场内SST下降,渔场重心主要分布在南部海域。研究表明,中国东海鲐鱼渔场时空分布受到厄尔尼诺和拉尼娜调控的海表温度变化的显著影响。 相似文献