scholarly journals Simple stochastic dynamical models capturing the statistical diversity of El Niño Southern Oscillation

2017 ◽  
Vol 114 (7) ◽  
pp. 1468-1473 ◽  
Author(s):  
Nan Chen ◽  
Andrew J. Majda
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Coupled Model ◽  
La Niña ◽  
Trade Wind ◽  
El Nino Southern Oscillation ◽  
Central Pacific ◽  
La Nina ◽  
Super El Niño

The El Niño Southern Oscillation (ENSO) has significant impact on global climate and seasonal prediction. A simple modeling framework is developed here that automatically captures the statistical diversity of ENSO. First, a stochastic parameterization of the wind bursts including both westerly and easterly winds is coupled to a simple ocean–atmosphere model that is otherwise deterministic, linear, and stable. Second, a simple nonlinear zonal advection with no ad hoc parameterization of the background sea-surface temperature (SST) gradient and a mean easterly trade wind anomaly representing the multidecadal acceleration of the trade wind are both incorporated into the coupled model that enables anomalous warm SST in the central Pacific. Then a three-state stochastic Markov jump process is used to drive the wind burst activity that depends on the strength of the western Pacific warm pool in a simple and effective fashion. It allows the coupled model to simulate the quasi-regular moderate traditional El Niño, the super El Niño, and the central Pacific (CP) El Niño as well as the La Niña with realistic features. In addition to the anomalous SST, the Walker circulation anomalies at different ENSO phases all resemble those in nature. In particular, the coupled model succeeds in reproducing the observed episode during the 1990s, where a series of 5-y CP El Niños is followed by a super El Niño and then a La Niña. Importantly, both the variance and the non-Gaussian statistical features in different Niño regions spanning from the western to the eastern Pacific are captured by the coupled model.

scholarly journals The Impact of Obliquity Change on El Niño Southern Oscillation (ENSO) and La Niña Climate Episodes

2022 ◽  
Author(s):  
Paul C. Rivera
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Global Climate ◽  
Global Climate Model ◽  
La Niña ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
La Nina ◽  
The Impact

An alternative physical mechanism is proposed to describe the occurrence of the episodic El Nino Southern Oscillation (ENSO) and La Nina climatic phenomena. This is based on the earthquake-perturbed obliquity change (EPOCH) model previously discovered as a major cause of the global climate change problem. Massive quakes impart a very strong oceanic force that can move the moon which in turn pulls the earth’s axis and change the planetary obliquity. Analysis of the annual geomagnetic north-pole shift and global seismic data revealed this previously undiscovered force. Using a higher obliquity in the global climate model EdGCM and constant greenhouse gas forcing showed that the seismic-induced polar motion and associated enhanced obliquity could be the major mechanism governing the mysterious climate anomalies attributed to El Nino and La Nina cycles.

scholarly journals Response of regional climate and glacier ice proxies to El Niño-Southern Oscillation (ENSO) in the subtropical Andes

2008 ◽  
Vol 4 (1) ◽  
pp. 173-211
Author(s):  
E. Dietze ◽  
A. Kleber ◽  
M. Schwikowski
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Ice Core ◽  
La Niña ◽  
El Nino Southern Oscillation ◽  
Ion Concentrations ◽  
Major Ion ◽  
La Nina ◽  
Glacier Ice

Abstract. El Niño-Southern Oscillation (ENSO) is an important element of earth's ocean-climate system. To further understand its past variability, proxy records from climate archives need to be studied. Ice cores from high alpine glaciers may contain high resolution ENSO proxy information, given the glacier site is climatologically sensitive to ENSO. We investigated signals of ENSO in the climate of the subtropical Andes in the proximity of Cerro Tapado glacier (30°08' S, 69°55' W, 5550 m a.s.l.), where a 36 m long ice core was drilled in 1999 (Ginot, 2001). We used annual and semi-annual precipitation and temperature time series from regional meteorological stations and interpolated grids for correlation analyses with ENSO indices and ice core-derived proxies (net accumulation, stable isotope ratio δ18O, major ion concentrations). The total time period investigated here comprises 1900 to 2000, but varies with data sets. Only in the western, i.e. Mediterranean Andes precipitation is higher (lower) during El Niño (La Niña) events, especially at higher altitudes, due to the latitudinal shift of frontal activity during austral winters. However, the temperature response to ENSO is more stable in space and time, being higher (lower) during El Niño (La Niña) events in most of the subtropical Andes all year long. From a northwest to southeast teleconnection gradient, we suggest a regional water vapour feedback triggers temperature anomalies as a function of ENSO-related changes in regional pressure systems, Pacific sea surface temperature and tropical moisture input. Tapado glacier ice proxies are found to be predominantly connected to eastern Andean summer rain climate, which contradicts previous studies and the modern mean spatial boundary between subtropical summer and winter rain climate derived from the grid data. The only ice core proxy showing a response to ENSO is the major ion concentrations, via local temperature indicating reduced sublimation and mineral dust input during El Niño years.

scholarly journals An Analysis of Anomalous Winter and Spring Tornado Frequency by Phase of the El Niño/Southern Oscillation, the Global Wind Oscillation, and the Madden-Julian Oscillation

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Todd W. Moore ◽  
Jennifer M. St. Clair ◽  
Tiffany A. DeBoer
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
La Niña ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Madden Julian Oscillation ◽  
La Nina ◽  
Upper Level ◽  
Favorable Conditions

Winter and spring tornado activity tends to be heightened during the La Niña phase of the El Niño/Southern Oscillation and suppressed during the El Niño phase. Despite these tendencies, some La Niña seasons have fewer tornadoes than expected and some El Niño seasons have more than expected. To gain insight into such anomalous seasons, the two La Niña winters and springs with the fewest tornadoes and the two El Niño winters and springs with the most tornadoes between 1979 and 2016 are identified and analyzed in this study. The relationships between daily tornado count and the Global Wind Oscillation and Madden-Julian Oscillation in these anomalous seasons are also explored. Lastly, seasonal and daily composites of upper-level flow, low-level flow and humidity, and atmospheric instability are generated to describe the environmental conditions in the anomalous seasons. The results of this study highlight the potential for large numbers of tornadoes to occur in a season if favorable conditions emerge in association with individual synoptic-scale events, even during phases of the El Niño/Southern Oscillation, Global Wind Oscillation, and Madden-Julian Oscillation that seem to be unfavorable for tornadoes. They also highlight the potential for anomalously few tornadoes in a season even when the oscillations are in favorable phases.

scholarly journals The ENSO–Asian Monsoon Interaction in a Coupled Ocean–Atmosphere GCM

2007 ◽  
Vol 20 (20) ◽  
pp. 5164-5177 ◽  
Author(s):  
Ying Li ◽  
Riyu Lu ◽  
Buwen Dong
Keyword(s):  
El Niño ◽  
Asian Monsoon ◽  
El Nino ◽  
Southern Oscillation ◽  
La Niña ◽  
Enso Cycle ◽  
Central Pacific ◽  
La Nina ◽  
Ocean Atmosphere ◽  
The Relationship

Abstract In this study, the authors evaluate the (El Niño–Southern Oscillation) ENSO–Asian monsoon interaction in a version of the Hadley Centre coupled ocean–atmosphere general circulation model (CGCM) known as HadCM3. The main focus is on two evolving anomalous anticyclones: one located over the south Indian Ocean (SIO) and the other over the western North Pacific (WNP). These two anomalous anticyclones are closely related to the developing and decaying phases of the ENSO and play a crucial role in linking the Asian monsoon to ENSO. It is found that the HadCM3 can well simulate the main features of the evolution of both anomalous anticyclones and the related SST dipoles, in association with the different phases of the ENSO cycle. By using the simulated results, the authors examine the relationship between the WNP/SIO anomalous anticyclones and the ENSO cycle, in particular the biennial component of the relationship. It is found that a strong El Niño event tends to be followed by a more rapid decay and is much more likely to become a La Niña event in the subsequent winter. The twin anomalous anticyclones in the western Pacific in the summer of a decaying El Niño are crucial for the transition from an El Niño into a La Niña. The El Niño (La Niña) events, especially the strong ones, strengthen significantly the correspondence between the SIO anticyclonic (cyclonic) anomaly in the preceding autumn and WNP anticyclonic (cyclonic) anomaly in the subsequent spring, and favor the persistence of the WNP anomaly from spring to summer. The present results suggest that both El Niño (La Niña) and the SIO/WNP anticyclonic (cyclonic) anomalies are closely tied with the tropospheric biennial oscillation (TBO). In addition, variability in the East Asian summer monsoon, which is dominated by the internal atmospheric variability, seems to be responsible for the appearance of the WNP anticyclonic anomaly through an upper-tropospheric meridional teleconnection pattern over the western and central Pacific.

scholarly journals Differential Imprints of Distinct ENSO Flavors in Global Patterns of Very Low and High Seasonal Precipitation

2021 ◽  
Vol 3 ◽  
Author(s):  
Marc Wiedermann ◽  
Jonatan F. Siegmund ◽  
Jonathan F. Donges ◽  
Reik V. Donner
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Spatial Scales ◽  
La Niña ◽  
Seasonal Precipitation ◽  
Central Pacific ◽  
Regional Patterns ◽  
La Nina ◽  
Very High

The effects of El Niño's two distinct flavors, East Pacific (EP) and Central Pacific (CP)/Modoki El Niño, on global climate variability have been studied intensively in recent years. Most of these studies have made use of linear multivariate statistics or composite analysis. Especially the former assumes the same type of linear statistical dependency to apply across different phases of the El Niño–Southern Oscillation (ENSO), which appears not necessarily a justified assumption. Here, we statistically evaluate the likelihood of co-occurrences between very high or very low seasonal precipitation sums over vast parts of the global land surface and the presence of the respective EP and CP types of both, El Niño and La Niña. By employing event coincidence analysis, we uncover differential imprints of both flavors on very low and very high seasonal precipitation patterns over distinct regions across the globe, which may severely affect, among others, agricultural and biomass production or public health. We particularly find that EP periods exhibit statistically significant event coincidence rates with hydrometeorological anomalies at larger spatial scales, whereas sparser patterns emerge along with CP periods. Our statistical analysis confirms previously reported interrelations for EP periods and uncovers additional distinct regional patterns of very high/low seasonal precipitation, such as increased rainfall over Central Asia alongside CP periods that have to our knowledge not been reported so far. Our results demonstrate that a thorough distinction of El Niño and La Niña into their two respective flavors could be crucial for understanding the emergence of strong regional hydrometeorological anomalies and anticipating their associated ecological and socioeconomic impacts.

scholarly journals El Niño Southern Oscillation (1896 to 2016): Quantifying Effects on Winter Precipitation and Temperature in Southwest Ohio, USA

2021 ◽  
Vol 121 (2) ◽  
pp. 64-77
Author(s):  
Robert W. Ritzi ◽  
Lauren M. Roberson ◽  
Michael Bottomley
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Winter Precipitation ◽  
Winter Temperature ◽  
La Niña ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
La Nina ◽  
Precipitation And Temperature

Continental-scale studies of North America suggest that the El Niño Southern Oscillation (ENSO) can cause winters to be warmer, with less precipitation, during El Niño conditions and colder, with more precipitation, during La Niña conditions in the Midwest United States. Two sources of historical records of precipitation and temperature in southwest Ohio from 1896 to 2016 were analyzed. Three statistical methodologies were used to test the hypothesis that anomalies in winter temperature and precipitation occurred in relation to ENSO phases. Eighty percent of El Niño winters had below-average winter precipitation; the average anomaly was −5 cm. Precipitation decreased with increase in El Niño strength as measured by the Multivariate ENSO Index (MEI). These results were statistically significant beyond the 95% level. However, variation in MEI only accounted for 3% of the overall variability in winter precipitation. Many of the drier winters on record, including the extrema, occurred during neutral winters. During La Niña winters precipitation was not statistically significantly different from that in neutral winters. Winter temperature was not statistically significantly different during El Niño and La Niña winters within the century of record. The results were consistent between separate analyses of data from the 2 different sources.

The impact of El Niño Southern Oscillation on seasonal drought in the southern Australian grainbelt

2010 ◽  
Vol 61 (7) ◽  
pp. 528 ◽  
Author(s):  
P. T. Hayman ◽  
A. M. Whitbread ◽  
D. L. Gobbett
Keyword(s):  
Cluster Analysis ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Moisture Stress ◽  
La Niña ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
High Rainfall ◽  
La Nina

The cropping simulation model APSIM (Agricultural Production Systems Simulator) was used to investigate the pattern of seasonal moisture stress during the growing season for four medium- to high-rainfall regions and four low-rainfall regions in the southern Australian grains belt over the period 1906–2007. Cluster analysis of the pattern of crop water stress experienced by each simulated crop was used to devise season types for the study sites. Average crop moisture stress for two periods up to grain filling, i.e. germination to 600°C days of thermal accumulation (~Zadoks 0–32) and from 600 to 1200 days of thermal accumulation (~Zadoks 32–71), was used to devise a classification of season type: low moisture stress early and late (L-L), low early and high late (L-H), high early and low late (H-L) and high early and late (H-H). Using regional rainfall we found that El Niño events are associated with double the risk of the season being in the lowest tercile from 33 to 67% and La Niña events increase the chance of being in the top tercile to 50%. Although there was a wide range of simulated yields in El Niño and La Niña years, for most sites the average yields were lower in El Niño years and higher in La Niña years. For most sites in the study 6 or 7 of the worst 10 years were El Niño, 3 Neutral and 1 or nil cases were La Niña events. This contrasts with a pattern assuming no El Niño Southern Oscillation (ENSO) influence of 2 El Niño, 6 Neutral and 2 La Niña events. Analysis of the relationship of season types identified by the cluster analysis to ENSO showed significant results for high-rainfall sites but not for low-rainfall sites. One of the reasons for this is that in low-rainfall sites, moisture stress occurs in most seasons. We conclude that there is good reason for farmers and advisers in South Australia to pay attention to a forecast of ENSO for the coming season as one part of their risk management strategy. We conclude on the need to think clearly about drought and aridity in these low-rainfall environments and comment on how this analysis further questions canopy management as a means of dealing with drought risk.

scholarly journals KORELASI MULTIVARIABEL ENSO, MONSUN DAN DIPOLEMODE TERHADAP VARIABILITAS CURAH HUJAN DI MALUKU

2018 ◽  
Vol 12 (1) ◽  
pp. 7
Author(s):  
Alexander Y. Elake ◽  
Merlin Talahatu ◽  
Pieldrie Nanlohy
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
La Niña ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Dipole Mode ◽  
La Nina

Analisis korelasi multivariabel antara curah hujan diMaluku (Ambon, Tual, dan Saumlaki) dengan anomali suhu the El Niño Southern Oscillation (ENSO) di daerah Niño 3.4 Samudera Pasifik, angin Monsun di wilayah Maluku serta anomali suhu Dipole Mode Event (DME) di Samudera Hindia telah dilakukan dengan analisa korelasi parsial dan berganda. Analisis tersebut dilakukan untuk data selama 10 tahun kalender yaitu dari Januari 2005 – Desember 2014 yang meliputi dua periode kejadian El Niño (tahun 2006/07 dan 2009/10), dua tahun fasa ENSO Normal (2005 dan 2013), dan tiga periode La Niña (2007/08, 2010/11, dan 2011/12). Pengaruh interaksi ENSO, Monsun dan Dipole Mode terhadap curah hujan Maluku ditunjukkan oleh nilai koefisien korelasi berganda (rb1) yang berkisar antara 0,748 – 0,999 dan nilai koefisien penentu berganda (rpb1) dengan kisaran 55,9–99,8% pada fasa El Niño. Sedangkan untuk fasa ENSO Normal nilainya berturut-turut rb2 = 0,807–0,905 dan rpb2 = 64,6 – 81,9%, dan untuk fasa fasa La Niña adalah rb3 = 0,674–0,964 dan rpb3 = 45,4– 92,9%. Pengaruh ENSO yang dominan terhadap curah hujan Ambon terlihat pada fasa El Niño dan fasa La Niña, sedangkan Monsun lebih dominan pada ENSO Normal. Untuk Tual, pengaruh ENSO, Monsun, dan Dipole Mode sama-sama terlihat pada fasa El Niño dan fasa La Niña, sedangkan Monsun lebih dominan dari Dipole Mode pada ENSO Normal. Sementara pengaruh Dipole Mode sangat dominan terhadap curah hujan Saumlaki.

scholarly journals PERGERAKAN ZONA KONVERGENSI DI SAMUDERA PASIFIK BAGIAN BARAT BERDASARKAN DATA INSITU DAN SATELIT

2015 ◽  
Vol 10 (2) ◽  
pp. 75
Author(s):  
Faisal Hamzah ◽  
Eko Susilo ◽  
Iis Triyulianti ◽  
Agus Setiawan
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
La Niña ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
La Nina

Samudera Pasifik berperan penting dalam siklus El-Nino Southern Oscillation (ENSO) dan berpengaruh signifikan pada kegiatan penangkapan tuna di Indonesia, khususnya ikan Cakalang. Penelitian ini bertujuan mengetahui pola pergerakan zona konvergensi di Samudera Pasifik bagian Barat dengan mengamati pergerakan parameter oseanografi seperti suhu, salinitas, klorofil-a, dan produktivitas primer. Data parameter oseanografi tersebut terdiri dari data insitu, data satelit maupun hasil pemodelan. Hasil analisis menunjukan adanya pergerakan zona konvergensi di Barat Pasifik yang dicirikan variabel proksi yaitu isotermal 29°C, isohalin 34,6 psu, konsenrasi klorofil-a sebesar 0,1 mg/m3 dan NPP 300 mgC/m2/day. Pola pergerakan zona konvergensi baik secara horisontal maupun vertikal dipengaruhi oleh ENSO. Pada saat terjadi La-Nina massa air dengan suhu yang hangat bergeser ke arah Barat yang diikuti dengan meningkatnya kesuburan perairan. Pergerakan vertikal massa air hangat terjadi pada kedalaman 25-75 m (suhu) dan 50 m (salinitas). Namun pada saat El-Nino massa air hangat bergerak ke arah Timur Samudera Pasifik. Fluktuasi produksi tangkapan ikan Cakalang di perairan Indonesia Timur mengikuti pola pergerakan zona konvergensi tersebut. Peningkatan jumlah produksi ikan Cakalang di Kota Sorong meningkat seiring dengan keberadaan zona konvergensi di bagian Barat (La-Nina), namun di Propinsi Papua menunjukan pola sebaliknya.

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