The Scientific Issues Associated with El Niño 1997-1998

2000 ◽  
Author(s):  
Stanley A. Changnon
Keyword(s):  
Global Warming ◽  
El Niño ◽  
El Nino ◽  
Scientific Information ◽  
Weather Conditions ◽  
General Information ◽  
Decision Makers ◽  
Climate Conditions ◽  
Seasonal Climate ◽  
The Public

The development of a record large El Niño event and its ensuing major effects on the nation’s weather over an eight-month period created a scientific event of major proportions. Key science-related questions that developed during El Niño 97-98 included: • Who was issuing El Niño -based climate predictions and for what conditions? • What kinds of weather conditions were caused by El Niño ? • What types of impacts were being projected as a result of the El Niño weather? • How accurate and useful were the El Niño -based climate predictions? • How accurate were the oceanic predictions relating to the development, intensification, and dissipation of El Niño 97-98? • Was the record-size event caused by global warming? Answers to such questions define the scientific information transmitted to the public, the scientific community, and decision makers during the event. This assessment focused on the scientific information that appeared during the period from May 1997 to June 1998, but it also included information that appeared a few months after El Niño ended (i.e., into early 1999), since these issuances reflect the thoughts and findings generated by scientists during the event. Topics assessed included: (1) the sources of the scientific information, (2) how the information was interpreted and by whom, (3) the accuracy of what was presented by different sources, and (4) the scientific issues that emerged, some of which involved disagreements and/or caused potential confusion for decision makers and the public. Most of the information assessed herein was extracted from the Internet, newspaper stories, and scientific documents published during the June 1997-June 1998 period. What scientific information relating to El Niño 97-98 was measured? We assessed the presentations of the physical descriptions of El Niño and ENSO and the predictions, the predictions based on El Niño conditions of future seasonal climate conditions as well as the resulting physical and societal impacts, the verifications of the seasonal climate predictions, and other, more general information about El Niño 97-98 that emerged, such as its magnitude in comparison to past El Niño events and its possible relationship to other conditions, such as global warming.

scholarly journals El Niño modifies nutrient status in oil palm and helps foliage to recover from yellowing symptoms: new analysis and perspectives

2021 ◽  
Vol 30 ◽  
pp. 34
Author(s):  
Bernard Dubos ◽  
Marcel de Raïssac
Keyword(s):  
Oil Palm ◽  
El Niño ◽  
Magnesium Deficiency ◽  
El Nino ◽  
Southern Oscillation ◽  
Weather Conditions ◽  
Annual Rainfall ◽  
Mineral Deficiency ◽  
Local Climate ◽  
Climate Conditions

In Ecuador, oil palm plantations from the Quinindé-Quevedo region are subject to El Niño/Southern Oscillation (ENSO) with a preponderance of La Niña weather conditions. With more than 2,000 mm, the total annual rainfall is theoretically non-limiting but, with only 1,000 h, the total annual sunshine is well below the 1,800 h minimum recommended. Starting in the 1970s, the frequent occurrence of frond yellowing symptoms in the region became a recurrent worry for growers, convinced that they were facing the expression of a mineral deficiency. In this study, we used experimental results to examine the actual role of mineral nutrition in yellowing manifestation. We described the effects of two El Niño events (1982/1983 and 1997/1998) on climate variables and analysed their putative consequences on palm physiological functioning that could explain the observed foliage recovery. Our analysis led us to conclude that a direct mineral deficiency was not involved, as the soil reserves for the main nutrients were not to blame. We rejected the most frequently proposed hypothesis, whereby yellowing is caused by magnesium deficiency. Our study revealed the key role played by nitrogen, the best indicator of yellowing. Variations in N status appear to be linked to the same factors that determine the symptoms and we opted for the hypothesis of physiological disruption generated by low solar radiation levels under normal conditions. The study also reveals the need to consider specific optimum contents for N and Mg and to adjust fertilizer recommendations to local climate conditions.

El Niño, 1997-1998

2000 ◽  
Keyword(s):  
News Media ◽  
El Niño ◽  
El Nino ◽  
The United States ◽  
Time Span ◽  
Economic Consequences ◽  
Decision Makers ◽  
The Public ◽  
The Social ◽  
Key Issues

This book will cover the time span from the first indications of El Nino (May 1997) until its reversal (June 1998). The focus will be largely on the United States, where El Nino produced widespread changes in how the public perceives weather and in the accuracy of forecasts Among the key issues it will examine are how the news media interpreted and dramatixed El Nino and the reaction both of the public and decision-makers (the latter based on interviews with agribusiness, utilities, water management agencies, etc.); the scientific issues emerging from the event; and the social and economic consequences of the event. Finally, it will suggest what can and should be done when El Nino occurs in the future.

scholarly journals Teaching Science in Today’s Society: The Case of Particle Physics for Primary Schools

Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 169
Author(s):  
Cristina Lazzeroni ◽  
Sandra Malvezzi ◽  
Andrea Quadri
Keyword(s):  
Particle Physics ◽  
Primary Schools ◽  
Scientific Information ◽  
Decision Makers ◽  
Educational Institutions ◽  
The Public ◽  
The Past ◽  
Rapid Changes ◽  
The Subject ◽  
Ongoing Project

The rapid changes in science and technology witnessed in recent decades have significantly contributed to the arousal of the awareness by decision-makers and the public as a whole of the need to strengthen the connection between outreach activities of universities and research institutes and the activities of educational institutions, with a central role played by schools. While the relevance of the problem is nowadays unquestioned, no unique and fully satisfactory solution has been identified. In the present paper we would like to contribute to the discussion on the subject by reporting on an ongoing project aimed to teach Particle Physics in primary schools. We will start from the past and currently planned activities in this project in order to establish a broader framework to describe the conditions for the fruitful interplay between researchers and teachers. We will also emphasize some aspects related to the dissemination of outreach materials by research institutions, in order to promote the access and distribution of scientific information in a way suited to the different age of the target students.

scholarly journals Addendum: Butterfly effect and a self-modulating El Niño response to global warming

Nature ◽  
2021 ◽  
Vol 591 (7849) ◽  
pp. E14-E15
Author(s):  
Wenju Cai ◽  
Benjamin Ng ◽  
Tao Geng ◽  
Lixin Wu ◽  
Agus Santoso ◽  
...  
Keyword(s):  
Global Warming ◽  
El Niño ◽  
El Nino ◽  
Butterfly Effect

scholarly journals Changes in Independency between Two Types of El Niño Events under a Greenhouse Warming Scenario in CMIP5 Models

2015 ◽  
Vol 28 (19) ◽  
pp. 7561-7575 ◽  
Author(s):  
Yoo-Geun Ham ◽  
Yerim Jeong ◽  
Jong-Seong Kug
Keyword(s):  
Global Warming ◽  
El Niño ◽  
El Nino ◽  
Western Pacific ◽  
Cmip5 Models ◽  
Greenhouse Warming ◽  
Central Pacific ◽  
El Niño Events ◽  
The Western Pacific ◽  
El Nino Events

Abstract This study uses archives from phase 5 of the Coupled Model Intercomparison Project (CMIP5) to investigate changes in independency between two types of El Niño events caused by greenhouse warming. In the observations, the independency between cold tongue (CT) and warm pool (WP) El Niño events is distinctively increased in recent decades. The simulated changes in independency between the two types of El Niño events according to the CMIP5 models are quite diverse, although the observed features are simulated to some extent in several climate models. It is found that the climatological change after global warming is an essential factor in determining the changes in independency between the two types of El Niño events. For example, the independency between these events is increased after global warming when the climatological precipitation is increased mainly over the equatorial central Pacific. This climatological precipitation increase extends convective response to the east, particularly for CT El Niño events, which leads to greater differences in the spatial pattern between the two types of El Niño events to increase the El Niño independency. On the contrary, in models with decreased independency between the two types of El Niño events after global warming, climatological precipitation is increased mostly over the western Pacific. This confines the atmospheric response to the western Pacific in both El Niño events; therefore, the similarity between them is increased after global warming. In addition to the changes in the climatological state after global warming, a possible connection of the changes in the El Niño independency with the historical mean state is discussed in this paper.

scholarly journals Estimates of the Water Vapor Climate Feedback during El Niño–Southern Oscillation

2009 ◽  
Vol 22 (23) ◽  
pp. 6404-6412 ◽  
Author(s):  
A. E. Dessler ◽  
S. Wong
Keyword(s):  
Global Warming ◽  
Water Vapor ◽  
El Niño ◽  
Climate Models ◽  
El Nino ◽  
Southern Oscillation ◽  
Specific Humidity ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Water Vapor Feedback

Abstract The strength of the water vapor feedback has been estimated by analyzing the changes in tropospheric specific humidity during El Niño–Southern Oscillation (ENSO) cycles. This analysis is done in climate models driven by observed sea surface temperatures [Atmospheric Model Intercomparison Project (AMIP) runs], preindustrial runs of fully coupled climate models, and in two reanalysis products, the 40-yr European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA-40) and the NASA Modern Era Retrospective-Analysis for Research and Applications (MERRA). The water vapor feedback during ENSO-driven climate variations in the AMIP models ranges from 1.9 to 3.7 W m−2 K−1, in the control runs it ranges from 1.4 to 3.9 W m−2 K−1, and in the ERA-40 and MERRA it is 3.7 and 4.7 W m−2 K−1, respectively. Taken as a group, these values are higher than previous estimates of the water vapor feedback in response to century-long global warming. Also examined is the reason for the large spread in the ENSO-driven water vapor feedback among the models and between the models and the reanalyses. The models and the reanalyses show a consistent relationship between the variations in the tropical surface temperature over an ENSO cycle and the radiative response to the associated changes in specific humidity. However, the feedback is defined as the ratio of the radiative response to the change in the global average temperature. Differences in extratropical temperatures will, therefore, lead to different inferred feedbacks, and this is the root cause of spread in feedbacks observed here. This is also the likely reason that the feedback inferred from ENSO is larger than for long-term global warming.

scholarly journals Global warming in Amazonia: impacts and Mitigation

2009 ◽  
Vol 39 (4) ◽  
pp. 1003-1011 ◽  
Author(s):  
Philip Martin Fearnside
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Forest Fires ◽  
El Niño ◽  
El Nino ◽  
Cost Effective ◽  
Climatic Conditions ◽  
Carbon Accounting ◽  
Amazon Forest ◽  
Temperature Oscillations

Global warming has potentially catastrophic impacts in Amazonia, while at the same time maintenance of the Amazon forest offers one of the most valuable and cost-effective options for mitigating climate change. We know that the El Niño phenomenon, caused by temperature oscillations of surface water in the Pacific, has serious impacts in Amazonia, causing droughts and forest fires (as in 1997-1998). Temperature oscillations in the Atlantic also provoke severe droughts (as in 2005). We also know that Amazonian trees die both from fires and from water stress under hot, dry conditions. In addition, water recycled through the forest provides rainfall that maintains climatic conditions appropriate for tropical forest, especially in the dry season. What we need to know quickly, through intensified research, includes progress in representing El Niño and the Atlantic oscillations in climatic models, representation of biotic feedbacks in models used for decision-making about global warming, and narrowing the range of estimating climate sensitivity to reduce uncertainty about the probability of very severe impacts. Items that need to be negotiated include the definition of "dangerous" climate change, with the corresponding maximum levels of greenhouse gases in the atmosphere. Mitigation of global warming must include maintaining the Amazon forest, which has benefits for combating global warming from two separate roles: cutting the flow the emissions of carbon each year from the rapid pace of deforestation, and avoiding emission of the stock of carbon in the remaining forest that can be released by various ways, including climate change itself. Barriers to rewarding forest maintenance include the need for financial rewards for both of these roles. Other needs are for continued reduction of uncertainty regarding emissions and deforestation processes, as well as agreement on the basis of carbon accounting. As one of the countries most subject to impacts of climate change, Brazil must assume the leadership in fighting global warming.

scholarly journals Influence of the 2015–2016 El Niño on the record-breaking mangrove dieback along northern Australia coast

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Abhik ◽  
Pandora Hope ◽  
Harry H. Hendon ◽  
Lindsay B. Hutley ◽  
Stephanie Johnson ◽  
...  
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Low Frequency ◽  
Multiple Linear Regression Model ◽  
Frequency Component ◽  
Enso Cycle ◽  
Northern Australia ◽  
Climate Conditions

AbstractThis study investigates the underlying climate processes behind the largest recorded mangrove dieback event along the Gulf of Carpentaria coast in northern Australia in late 2015. Using satellite-derived fractional canopy cover (FCC), variation of the mangrove canopies during recent decades are studied, including a severe dieback during 2015–2016. The relationship between mangrove FCC and climate conditions is examined with a focus on the possible role of the 2015–2016 El Niño in altering favorable conditions sustaining the mangroves. The mangrove FCC is shown to be coherent with the low-frequency component of sea level height (SLH) variation related to the El Niño Southern Oscillation (ENSO) cycle in the equatorial Pacific. The SLH drop associated with the 2015–2016 El Niño is identified to be the crucial factor leading to the dieback event. A stronger SLH drop occurred during austral autumn and winter, when the SLH anomalies were about 12% stronger than the previous very strong El Niño events. The persistent SLH drop occurred in the dry season of the year when SLH was seasonally at its lowest, so potentially exposed the mangroves to unprecedented hostile conditions. The influence of other key climate factors is also discussed, and a multiple linear regression model is developed to understand the combined role of the important climate variables on the mangrove FCC variation.

scholarly journals ESTUDOS DE TELECONEXÕES ATMOSFÉRICAS E POSSIBILIDADES DE AVANÇOS NA CLIMATOLOGIA GEOGRÁFICA: CONCEITOS, FONTES DE DADOS E TÉCNICAS (ATMOSPHERIC TELECONNECTIONS RESEARCH AND POSSIBILITIES OF ADVANCES IN WEATHER CONDITIONS GEOGRAPHIC: CONCEPTS, SOURCES AND TECHNIQUES)

2016 ◽  
Vol 19 ◽  
Author(s):  
Leila Limberger
Keyword(s):  
El Niño ◽  
El Nino ◽  
Weather Conditions ◽  
Atmospheric Teleconnections

RESUMO: A utilização do conceito de teleconexões atmosféricas pela Climatologia Geográfica permite análise do globo como um todo complexo. Isso porque com o conceito de teleconexões compreende-se que alterações na interação oceano-atmosfera podem se deslocar por meio de ondas planetárias e atingir outros locais do globo (por exemplo, o fenômeno El Niño - Oscilação Sul). Para estudos utilizando-se do conceito de teleconexões atmosféricas são necessários dados globais de componentes atmosféricas, que podem ser obtidos a partir de download de conjuntos de dados disponibilizados por centros de pesquisas meteorológicas. Esses dados são interpolados em grades regulares, resultados de reanálises e/ou de modelos numéricos. Há também a disponibilização de softwares gratuitos adequados para o tratamento dos dados, com a possibilidade de utilização de pacotes estatísticos específicos. Dentre as principais vantagens  da utilização de dados globais interpolados em grade espacialmente regular estão a possibilidade de espacialização dos dados em escala global, análise de padrões espaciais característicos, a longevidade e ausência de falhas nas séries temporais, o grande número de variáveis atmosféricas disponíveis (no caso dos conjuntos de reanálise) e a consistência temporal e espacial dos dados.

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