scholarly journals Stochastic Parameterization and El Niño–Southern Oscillation

2017 ◽  
Vol 30 (1) ◽  
pp. 17-38 ◽  
Author(s):  
H. M. Christensen ◽  
Judith Berner ◽  
Danielle R. B. Coleman ◽  
T. N. Palmer
Keyword(s):  
El Niño ◽  
Multiplicative Noise ◽  
El Nino ◽  
Southern Oscillation ◽  
Coupled Model ◽  
Dominant Mode ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Convective Heating ◽  
Community Atmosphere Model

El Niño–Southern Oscillation (ENSO) is the dominant mode of interannual variability in the tropical Pacific. However, the models in the ensemble from phase 5 of the Coupled Model Intercomparison Project (CMIP5) have large deficiencies in ENSO amplitude, spatial structure, and temporal variability. The use of stochastic parameterizations as a technique to address these pervasive errors is considered. The multiplicative stochastically perturbed parameterization tendencies (SPPT) scheme is included in coupled integrations of the National Center for Atmospheric Research (NCAR) Community Atmosphere Model, version 4 (CAM4). The SPPT scheme results in a significant improvement to the representation of ENSO in CAM4, improving the power spectrum and reducing the magnitude of ENSO toward that observed. To understand the observed impact, additive and multiplicative noise in a simple delayed oscillator (DO) model of ENSO is considered. Additive noise results in an increase in ENSO amplitude, but multiplicative noise can reduce the magnitude of ENSO, as was observed for SPPT in CAM4. In light of these results, two complementary mechanisms are proposed by which the improvement occurs in CAM. Comparison of the coupled runs with a set of atmosphere-only runs indicates that SPPT first improve the variability in the zonal winds through perturbing the convective heating tendencies, which improves the variability of ENSO. In addition, SPPT improve the distribution of westerly wind bursts (WWBs), important for initiation of El Niño events, by increasing the stochastic component of WWB and reducing the overly strong dependency on SST compared to the control integration.

scholarly journals Correction to: The impact of stochastic physics on the El Niño Southern Oscillation in the EC-Earth coupled model

2019 ◽  
Vol 53 (3-4) ◽  
pp. 2479-2479 ◽  
Author(s):  
Chunxue Yang ◽  
Hannah M. Christensen ◽  
Susanna Corti ◽  
Jost von Hardenberg ◽  
Paolo Davini
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Coupled Model ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
The Impact ◽  
Stochastic Physics

A simple ocean-atmosphere coupled model for the origin of a warm El Niño Southern Oscillation event

1989 ◽  
Vol 329 (1604) ◽  
pp. 225-236 ◽  
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Asian Summer Monsoon ◽  
Coupled Model ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Quasi Biennial Oscillation ◽  
Mature Phase ◽  
Ocean Atmosphere

A simple ocean-atmosphere coupled model is developed to investigate the evolution of a warm El Niño event in the tropical Pacific Ocean. In the absence of climatological winds the model readily evolves a realistic eastward-propagating structure provided that warm sea surface temperature (sst) covers the entire equatorial ocean uniformly. The final state of the model is similar to the mature phase of El Niño. In the presence of realistic climatological winds, however, the model behaves in a different way. It remains in a cold La Nina phase without showing any significant eastward propagation of an air-sea coupled coherent structure. Based on these model results and recent data analyses on the tropospheric quasi-biennial oscillation, it is argued that the Asian summer monsoon before and after the warm phase of El Niño Southern Oscillation is possible.

scholarly journals On the role of oceanic entrainment temperature (<I>T</I><sub>e</sub>) in decadal changes of El Niño/Southern Oscillation

2011 ◽  
Vol 29 (3) ◽  
pp. 529-540 ◽  
Author(s):  
J. Zhu ◽  
G. Zhou ◽  
R.-H. Zhang ◽  
Z. Sun
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Thermal Structure ◽  
Coupled Model ◽  
Coupled System ◽  
Subsurface Water ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation

Abstract. The role of decadal changes in ocean thermal structure in modulating El Niño/Southern Oscillation (ENSO) properties was examined using a hybrid coupled model (HCM), consisting of a statistical atmospheric model and an oceanic general circulation model (OGCM) with an explicitly embedded empirical parameterization for the temperature of subsurface water entrained into the mixed layer (Te), which was constructed via an EOF analysis of model-based historical data. Using the empirical Te models constructed from two subperiods, 1963–1979 (Te63−79) and 1980–1996 (Te80−96), the coupled system exhibits striking different properties of interannual variability, including oscillation periods and the propagation characteristic of sea surface temperature anomalies (SSTAs) along the equator. In the Te63−79 run, the model features a 2–3 yr oscillation and a westward propagation of SSTAs along the equator, while in the Te80−96 run, it is characterized by a 4–5 yr oscillation and an eastward propagation. Furthermore, a Lag Covariance Analysis (LCOA) was utilized to illustrate the leading physical processes responsible for decadal change in SST. It is shown that the change in the structure of Te acts to modulate the relative strength of the zonal advective and thermocline feedbacks in the coupled system, leading to changes in ENSO properties. Two additional sensitive experiments were conducted to further illustrate the respective roles of the changes in ocean mean states and in Te in modulating ENSO behaviors. These decadal changes in the simulated ENSO properties are consistent with the observed shift occurred in the late 1970s and a previous simulation performed with an intermediate coupled model (ICM) described in Zhang and Busalacchi (2005), indicating a dominant role Te plays in decadal ENSO changes.

scholarly journals The impact of stochastic physics on the El Niño Southern Oscillation in the EC-Earth coupled model

2019 ◽  
Vol 53 (5-6) ◽  
pp. 2843-2859 ◽  
Author(s):  
Chunxue Yang ◽  
Hannah M. Christensen ◽  
Susanna Corti ◽  
Jost von Hardenberg ◽  
Paolo Davini
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Coupled Model ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
The Impact ◽  
Stochastic Physics

VARIABILIDAD CLIMÁTICA, CAMBIO CLIMÁTICO Y PESQUERÍAS EN EL ECUADOR.

2012 ◽  
Vol 1 (1) ◽  
Author(s):  
Johnny Chavarría Viteri ◽  
Dennis Tomalá Solano
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Pacific Decadal Oscillation ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Current Action ◽  
Palabras Clave

La variabilidad climática es la norma que ha modulado la vida en el planeta. Este trabajo demuestra que las pesquerías y acuicultura costera ecuatorianas no son la excepción, puesto que tales actividades están fuertemente influenciadas por la variabilidad ENSO (El Niño-Oscilación del Sur) y PDO (Oscilación Decadal del Pacífico), planteándose que la señal del cambio climático debe contribuir a esta influencia. Se destaca también que, en el análisis de los efectos de la variabilidad climática sobre los recursos pesqueros, el esfuerzo extractivo también debe ser considerado. Por su parte, la acción actual de la PDO está afectando la señal del cambio climático, encontrándose actualmente en fases opuestas. Se espera que estas señales entren en fase a finales de esta década, y principalmente durante la década de los 20 y consecuentemente se evidencien con mayor fuerza los efectos del Cambio Climático. Palabras Clave: Variabilidad Climática, Cambio Climático, ENSO, PDO, Pesquerías, Ecuador. ABSTRACT Climate variability is the standard that has modulated life in the planet. This work shows that the Ecuadorian  fisheries and aquaculture are not the exception, since such activities are strongly influenced by ENSO variability (El Niño - Southern Oscillation) and PDO (Pacific Decadal Oscillation), considering that the signal of climate change should contribute to this influence. It also emphasizes that in the analysis of the effects of climate variability on the fishing resources, the extractive effort must also be considered. For its part, the current action of the PDO is affecting the signal of climate change, now found on opposite phases. It is hoped that these signals come into phase at the end of this decade, and especially during the decade of the 20’s and more strongly evidencing the effects of climate change. Keywords: Climate variability, climate change, ENSO (El Niño - Southern Oscillation) and PDO  (Pacific Decadal Oscillation); fisheries, Ecuador. Recibido: mayo, 2012Aprobado: agosto, 2012

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