Association between El Niño and extreme temperatures in southern South America in CMIP5 models. Part 1: model evaluation in the present climate

2021 ◽  
Author(s):  
S Collazo ◽  
M Barrucand ◽  
M Rusticucci
Keyword(s):  
South America ◽  
El Niño ◽  
Model Evaluation ◽  
El Nino ◽  
Cmip5 Models ◽  
Extreme Temperatures ◽  
Present Climate ◽  
Southern South America

El Niño and La Niña influence on mean river flows of southern South America in the 20th century

2019 ◽  
Vol 64 (8) ◽  
pp. 900-909 ◽  
Author(s):  
Guillermo J. Berri ◽  
Emilio Bianchi ◽  
Gabriela V. Müller
Keyword(s):  
South America ◽  
20Th Century ◽  
El Niño ◽  
El Nino ◽  
La Niña ◽  
River Flows ◽  
Southern South America ◽  
La Nina

scholarly journals Precipitation response to El Niño/La Niña events in Southern South America – emphasis in regional drought occurrences

2016 ◽  
Vol 42 ◽  
pp. 1-14 ◽  
Author(s):  
Olga Clorinda Penalba ◽  
Juan Antonio Rivera
Keyword(s):  
Time Series ◽  
South America ◽  
Time Scales ◽  
El Niño ◽  
El Nino ◽  
La Niña ◽  
Southern South America ◽  
La Nina ◽  
Precipitation Response ◽  
Drought Conditions

Abstract. The ENSO phenomenon is one of the key factors that influence the interannual variability of precipitation over Southern South America. The aim of this study is to identify the regional response of precipitation to El Niño/La Niña events, with emphasis in drought conditions. The standardized precipitation index (SPI) was used to characterize precipitation variabilities through the 1961–2008 period for time scales of 3 (SPI3) and 12 (SPI12) months. A regionalization based on rotated principal component analysis allowed to identify seven coherent regions for each of the time scales considered. In order to identify the regional influence of El Niño and La Niña events on the SPI time series, we calculated the mean SPI values for the El Niño and La Niña years and assessed its significance through bootstrap analysis. We found coherent and significant SPI responses to ENSO phases in most of the seven regions considered, mainly for the SPI12 time series. The precipitation response to La Niña events is characterized with regional deficits, identified with negative values of the SPI during the end of La Niña year and the year after. During El Niño events the precipitation response is reversed and more intense/consistent than in the case of La Niña events. This signal has some regional differences regarding its magnitude and timing, and the quantification of these features, together with the assessment of the SST composites during drought conditions provided critical baseline information for the agricultural and water resources sectors.

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 Do CMIP5 Models Show El Niño Diversity?

2020 ◽  
Vol 33 (5) ◽  
pp. 1619-1641 ◽  
Author(s):  
Jie Feng ◽  
Tao Lian ◽  
Jun Ying ◽  
Junde Li ◽  
Gen Li
Keyword(s):  
El Niño ◽  
El Nino ◽  
Heat Budget ◽  
Equatorial Pacific ◽  
Cmip5 Models ◽  
Budget Analysis ◽  
Future Global Warming ◽  
Central Equatorial Pacific ◽  
The Future ◽  
Sst Gradient

AbstractWhether the state-of-the-art CMIP5 models have different El Niño types and how the degree of modeled El Niño diversity would be impacted by the future global warming are still heavily debated. In this study, cluster analysis is used to investigate El Niño diversity in 30 CMIP5 models. As the method does not rely on any prior knowledge of the patterns of El Niño seen in observations, it provides a practical way to identify the degree of El Niño diversity in models. Under the historical scenario, most models show a poor degree of El Niño diversity in their own model world, primarily due to the lopsided numbers of events belonging to the two modeled El Niño types and the weak compactness of events in each cluster. Four models are found showing significant El Niño diversity, yet none of them captures the longitudinal distributions of the warming centers of the two El Niño types seen in the observations. Heat budget analysis of the sea surface temperature (SST) anomaly suggests that the degree of modeled El Niño diversity is highly related to the climatological zonal SST gradient over the western-central equatorial Pacific in models. As the gradient is weakened in most models under the future high-emission scenario, the degree of modeled El Niño diversity is further reduced in the future. The results indicate that a better simulation of the SST gradient over the western-central equatorial Pacific might allow a more reliable simulation/projection of El Niño diversity in most CMIP5 models.

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