scholarly journals Influence of the El Niño–Southern Oscillation on entry stratospheric water vapor in coupled chemistry–ocean CCMI and CMIP6 models

2021 ◽  
Vol 21 (5) ◽  
pp. 3725-3740
Author(s):  
Chaim I. Garfinkel ◽  
Ohad Harari ◽  
Shlomi Ziskin Ziv ◽  
Jian Rao ◽  
Olaf Morgenstern ◽  
...  
Keyword(s):  
Water Vapor ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Temperature Response ◽  
La Niña ◽  
Stratospheric Water Vapor ◽  
La Nina ◽  
Tropical Troposphere ◽  
Cold Point

Abstract. The connection between the dominant mode of interannual variability in the tropical troposphere, the El Niño–Southern Oscillation (ENSO), and the entry of stratospheric water vapor is analyzed in a set of model simulations archived for the Chemistry-Climate Model Initiative (CCMI) project and for Phase 6 of the Coupled Model Intercomparison Project. While the models agree on the temperature response to ENSO in the tropical troposphere and lower stratosphere, and all models and observations also agree on the zonal structure of the temperature response in the tropical tropopause layer, the only aspect of the entry water vapor response with consensus in both models and observations is that La Niña leads to moistening in winter relative to neutral ENSO. For El Niño and for other seasons, there are significant differences among the models. For example, some models find that the enhanced water vapor for La Niña in the winter of the event reverses in spring and summer, some models find that this moistening persists, and some show a nonlinear response, with both El Niño and La Niña leading to enhanced water vapor in both winter, spring, and summer. A moistening in the spring following El Niño events, the signal focused on in much previous work, is simulated by only half of the models. Focusing on Central Pacific ENSO vs. East Pacific ENSO, or temperatures in the mid-troposphere compared with temperatures near the surface, does not narrow the inter-model discrepancies. Despite this diversity in response, the temperature response near the cold point can explain the response of water vapor when each model is considered separately. While the observational record is too short to fully constrain the response to ENSO, it is clear that most models suffer from biases in the magnitude of the interannual variability of entry water vapor. This bias could be due to biased cold-point temperatures in some models, but others appear to be missing forcing processes that contribute to observed variability near the cold point.

scholarly journals Influence of ENSO on entry stratospheric water vapor in coupled chemistry-ocean CCMI and CMIP6 models

2020 ◽  
Author(s):  
Chaim Israel Garfinkel ◽  
Ohad Harari ◽  
Shlomi Ziskin ◽  
Jian Rao ◽  
Olaf Morgenstern ◽  
...  
Keyword(s):  
Water Vapor ◽  
Interannual Variability ◽  
El Niño ◽  
El Nino ◽  
Temperature Response ◽  
La Niña ◽  
Stratospheric Water Vapor ◽  
La Nina ◽  
Tropical Troposphere ◽  
Cold Point

Abstract. The connection between the dominant mode of interannual variability in the tropical troposphere, El Nino Southern Oscillation (ENSO), and entry of stratospheric water vapor, is analyzed in a set of the model simulations archived for the Chemistry-Climate Model Initiative (CCMI) project and for phase 6 of the Coupled Model Intercomparison Project. While the models agree on the temperature response to ENSO in the tropical troposphere and lower stratosphere, and all models also agree on the zonal structure of the response in the tropical tropopause layer, the only aspect of the entry water vapor with consensus is that La Nina leads to moistening in winter relative to neutral ENSO. For El Nino and for other seasons there are significant differences among the models. For example, some models find that the enhanced water vapor for La Nina in the winter of the event reverses in spring and summer, other models find that this moistening persists, while some show a nonlinear response with both El Nino and La Nina leading to enhanced water vapor in both winter, spring, and summer. Focusing on Central Pacific ENSO versus East Pacific ENSO, or temperatures in the mid-troposphere as compared to temperatures near the surface, does not narrow the inter-model discrepancies. Despite this diversity in response, the temperature response near the cold point can explain the response of water vapor when each model is considered separately. While the observational record is too short to fully constrain the response to ENSO, it is clear that most models suffer from biases in the magnitude of interannual variability of entry water vapor. This bias could be due to missing forcing processes that contribute to observed variability in cold point temperatures.

scholarly journals The effect of ENSO activity on lower stratospheric water vapor

2011 ◽  
Vol 11 (2) ◽  
pp. 4141-4166 ◽  
Author(s):  
F. Xie ◽  
W. Tian ◽  
J. Austin ◽  
J. Li ◽  
H. Tian ◽  
...  
Keyword(s):  
Water Vapor ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
El Niño ◽  
Lower Stratosphere ◽  
El Nino ◽  
La Niña ◽  
Stratospheric Water Vapor ◽  
La Nina ◽  
El Niño Events

Abstract. Using the ECMWF/NCEP reanalysis data, satellite observations from AURA MLS and UARS HALOE, and Oceanic Niño Index (ONI) data, the effects of El Niño and La Niña events on the stratospheric water vapor changes are investigated. Overall, El Niño events tend to moisten the lower stratosphere but dry the middle stratosphere. La Niña events are likely to dry the lower stratosphere over a narrow band of tropics (5° S–5° N) but have a moistening effect on the whole stratosphere when averaged over a broader region of tropics between 25° S–25° N. The moistening effect of La Niña events mainly occurs in lower stratosphere in the Southern Hemisphere tropics where a significant 20% increase in the tropical upwelling is caused by La Niña events. El Niño events have a more significant effect on the tropical upwelling in the Northern Hemisphere extratropics than in Southern Hemisphere extratropics. The net effect of ENSO activities on the lower stratospheric water vapor is stronger in the Southern Hemisphere tropics than in the Northern Hemisphere tropics.

scholarly journals Nonlinear response of tropical lower stratospheric temperature and water vapor to ENSO

2017 ◽  
Author(s):  
Chaim I. Garfinkel ◽  
Amit Gordon ◽  
Luke D. Oman ◽  
Feng Li ◽  
Sean Davis ◽  
...  
Keyword(s):  
Water Vapor ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
La Niña ◽  
Stratospheric Temperature ◽  
La Nina ◽  
El Niño Events ◽  
The Impact ◽  
El Nino Events

Abstract. A series of simulations using the NASA Goddard Earth Observing System Chemistry-Climate Model are analyzed in order to assess interannual and sub-decadal variability in tropical lower stratospheric temperature and water vapor over the past 35 years. The impact of El Niño-Southern Oscillation in this region is nonlinear. While moderate El Niño events lead to cooling in this region, strong El Niño events appear to lead to warming, even as the response of the large scale Brewer Dobson Circulation appears to scale nearly linearly with El Niño. The tropospheric warming associated with strong El Niño events extends into the tropical tropopause layer and up to the cold point, where it allows for more water vapor to enter the stratosphere. The net effect is that both strong La Niña and strong El Niño events lead to enhanced entry water vapor and stratospheric moistening. These results lead to the following interpretation of the millennial drop in water vapor in 2001: the very strong El Niño event in 1997/1998 followed by more than two consecutive years of La Niña led to enhanced lower stratospheric water vapor. As this period ended in early 2001, entry water vapor concentrations declined. The net effect is that sea surface temperature variability led to a decrease in water vapor of 0.14 ppmv after 2001, which accounts for approximately 23&thinsp.% of the observed drop.

scholarly journals Impact of El Niño/La Niña on the Seasonality of Oceanic Water Vapor: A Proposed Scheme for Determining the ITCZ

2005 ◽  
Vol 133 (10) ◽  
pp. 2940-2946 ◽  
Author(s):  
Ge Chen ◽  
Hui Lin
Keyword(s):  
Water Vapor ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
La Niña ◽  
Empirical Modeling ◽  
Oceanic Water ◽  
Alternative Scheme ◽  
La Nina ◽  
The Impact

Abstract Previous research has shown that oceanic water vapor (OWV) is a useful quantity for studying the low-frequency variability of the atmosphere–ocean system. In this work, 10 years (1993–2002) of high-quality OWV data derived from the Ocean Topography Experiment (TOPEX) microwave radiometer are used to investigate the impact of El Niño/La Niña on the amplitude and phase of the annual cycle. These results suggest that El Niños (La Niñas) can weaken (strengthen) the seasonality of OWV by decreasing (increasing) the annual amplitude. The change of amplitude is usually slight but significant, especially for the five most dynamic seasonal belts across the major continents at midlatitudes. The El Niño–Southern Oscillation (ENSO) impact on the annual phase of OWV is seen to be fairly systematic and geographically correlated. The most striking feature is a large-scale advancing/delay of about 10 days (as estimated through empirical modeling) for the midlatitude oceans of the Northern Hemisphere in reaching their summer maxima during the El Niño/La Niña years. In addition, an alternative scheme for estimating the mean position of the intertropical convergence zone (ITCZ) based on the annual phase map of OWV is proposed. This ITCZ climatology favors 4°N in mean latitude, and agrees with existing results in that its position meanders from 2°S to 8°N oceanwide, and stays constantly north of the equator over the Atlantic and eastern Pacific.

scholarly journals Nonlinear response of tropical lower-stratospheric temperature and water vapor to ENSO

2018 ◽  
Vol 18 (7) ◽  
pp. 4597-4615 ◽  
Author(s):  
Chaim I. Garfinkel ◽  
Amit Gordon ◽  
Luke D. Oman ◽  
Feng Li ◽  
Sean Davis ◽  
...  
Keyword(s):  
Water Vapor ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
La Niña ◽  
Boreal Spring ◽  
La Nina ◽  
El Niño Events ◽  
The Impact ◽  
El Nino Events

Abstract. A series of simulations using the NASA Goddard Earth Observing System Chemistry–Climate Model are analyzed in order to aid in the interpretation of observed interannual and sub-decadal variability in the tropical lower stratosphere over the past 35 years. The impact of El Niño–Southern Oscillation on temperature and water vapor in this region is nonlinear in boreal spring. While moderate El Niño events lead to cooling in this region, strong El Niño events lead to warming, even as the response of the large-scale Brewer–Dobson circulation appears to scale nearly linearly with El Niño. This nonlinearity is shown to arise from the response in the Indo-West Pacific to El Niño: strong El Niño events lead to tropospheric warming extending into the tropical tropopause layer and up to the cold point in this region, where it allows for more water vapor to enter the stratosphere. The net effect is that both strong La Niña and strong El Niño events lead to enhanced entry water vapor and stratospheric moistening in boreal spring and early summer. These results lead to the following interpretation of the contribution of sea surface temperatures to the decline in water vapor in the early 2000s: the very strong El Niño event in 1997/1998, followed by more than 2 consecutive years of La Niña, led to enhanced lower-stratospheric water vapor. As this period ended in early 2001, entry water vapor concentrations declined. This effect accounts for approximately one-quarter of the observed drop.

Rendimento de grãos de soja e de milho, no Rio Grande do Sul, não difere entre eventos El Niño Oscilação Sul

Agrometeoros ◽  
2018 ◽  
Vol 26 (1) ◽  
Author(s):  
Ronaldo Matzenauer ◽  
Bernadete Radin ◽  
Alberto Cargnelutti Filho
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Rio Grande ◽  
La Niña ◽  
Rio Grande Do Sul ◽  
La Nina ◽  
Significant Difference ◽  
Income Data ◽  
The Relationship

O objetivo deste trabalho foi avaliar a relação entre o fenômeno El Niño Oscilação Sul - ENOS e o rendimento de grãos de soja e de milho no Rio Grande do Sul e verificar a hipótese de que os eventos El Niño são favoráveis e os eventos La Niña são prejudiciais ao rendimento de grãos das culturas. Foram utilizados dados de rendimento de grãos dos anos agrícolas de 1974/75 a 2016/17, e relacionados com as ocorrências de eventos ENOS. Foram analisados os dados de rendimento observados na colheita e os dados estimados com a remoção da tendência tecnológica. Os resultados mostraram que não houve diferença significativa do rendimento médio de grãos de soja e de milho na comparação entre os eventos ENOS. Palavras-chave: El Niño, La Niña, safras agrícolas. Abstract – The objective of this work was to evaluate the relationship between the El Niño Southern Oscillation (ENSO) phenomenon with the grain yield of soybean and maize in Rio Grande do Sul state, Brazil and to verify the hypothesis that the El Niño events are favorable and the La Niña events are harmful to the culture’s grain yields. Were used data from the agricultural years of 1974/75 to 2016/17, and related to the occurrence of ENOS events. We analyzed income data observed at harvest and estimated data with technological tendency was removed. The results showed that there was no significant difference in the average yield of soybeans and corn in the comparison between events.

scholarly journals El Niño, La Niña, and the Forecastability of the Realized Variance of Heating Oil Price Movements

2021 ◽  
Vol 13 (14) ◽  
pp. 7987
Author(s):  
Mehmet Balcilar ◽  
Elie Bouri ◽  
Rangan Gupta ◽  
Christian Pierdzioch
Keyword(s):  
El Niño ◽  
Predictive Value ◽  
El Nino ◽  
Southern Oscillation ◽  
La Niña ◽  
Realized Variance ◽  
La Nina ◽  
Out Of Sample ◽  
Heating Oil ◽  
Price Movements

We use the heterogenous autoregressive (HAR) model to compute out-of-sample forecasts of the monthly realized variance (RV) of movements of the spot and futures price of heating oil. We extend the HAR–RV model to include the role of El Niño and La Niña episodes, as captured by the Equatorial Southern Oscillation Index (EQSOI). Using data from June 1986 to April 2021, we show evidence for several model configurations that both El Niño and La Niña phases contain information useful for forecasting subsequent to the realized variance of price movements beyond the predictive value already captured by the HAR–RV model. The predictive value of La Niña phases, however, seems to be somewhat stronger than the predictive value of El Niño phases. Our results have important implications for investors, as well as from the perspective of sustainable decisions involving the environment.

scholarly journals Role of the Indo-Pacific Interbasin Coupling in Predicting Asymmetric ENSO Transition and Duration

2012 ◽  
Vol 25 (9) ◽  
pp. 3321-3335 ◽  
Author(s):  
Masamichi Ohba ◽  
Masahiro Watanabe
Keyword(s):  
El Niño ◽  
General Circulation ◽  
El Nino ◽  
Southern Oscillation ◽  
La Niña ◽  
La Nina ◽  
The Pacific ◽  
Enso Asymmetry ◽  
Sst Anomalies

Warm and cold phases of El Niño–Southern Oscillation (ENSO) exhibit a significant asymmetry in their transition/duration such that El Niño tends to shift rapidly to La Niña after the mature phase, whereas La Niña tends to persist for up to 2 yr. The possible role of sea surface temperature (SST) anomalies in the Indian Ocean (IO) in this ENSO asymmetry is investigated using a coupled general circulation model (CGCM). Decoupled-IO experiments are conducted to assess asymmetric IO feedbacks to the ongoing ENSO evolution in the Pacific. Identical-twin forecast experiments show that a coupling of the IO extends the skillful prediction of the ENSO warm phase by about one year, which was about 8 months in the absence of the IO coupling, in which a significant drop of the prediction skill around the boreal spring (known as the spring prediction barrier) is found. The effect of IO coupling on the predictability of the Pacific SST is significantly weaker in the decay phase of La Niña. Warm IO SST anomalies associated with El Niño enhance surface easterlies over the equatorial western Pacific and hence facilitate the El Niño decay. However, this mechanism cannot be applied to cold IO SST anomalies during La Niña. The result of these CGCM experiments estimates that approximately one-half of the ENSO asymmetry arises from the phase-dependent nature of the Indo-Pacific interbasin coupling.

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.

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