scholarly journals Hydroclimate variability in the North China Plain and its link with El Niño-Southern Oscillation since 1784 A.D.: Insights from tree-ring celluloseδ18O

2011 ◽  
Vol 116 (D22) ◽  
pp. n/a-n/a ◽  
Author(s):  
Qiang Li ◽  
Takeshi Nakatsuka ◽  
Kimitaka Kawamura ◽  
Yu Liu ◽  
Huiming Song
Keyword(s):  
Tree Ring ◽  
El Niño ◽  
North China Plain ◽  
North China ◽  
El Nino ◽  
Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
The North ◽  
The North China Plain ◽  
Hydroclimate Variability

Modulation of the Global Atmospheric Circulation by Combined Activity in the Madden–Julian Oscillation and the El Niño–Southern Oscillation during Boreal Winter

2010 ◽  
Vol 23 (15) ◽  
pp. 4045-4059 ◽  
Author(s):  
Paul E. Roundy ◽  
Kyle MacRitchie ◽  
Jonas Asuma ◽  
Timothy Melino
Keyword(s):  
North Atlantic ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Boreal Winter ◽  
Madden Julian Oscillation ◽  
The North ◽  
The North Atlantic

Abstract Composite global patterns associated with the El Niño–Southern Oscillation (ENSO) and the Madden–Julian oscillation (MJO) are frequently applied to help make predictions of weather around the globe at lead times beyond a few days. However, ENSO modulates the background states through which the MJO and its global response patterns propagate. This paper explores the possibility that nonlinear variations confound the combined use of composites based on the MJO and ENSO separately. Results indicate that when both modes are active at the same time, the associated patterns in the global flow are poorly represented by simple linear combinations of composites based on the MJO and ENSO individually. Composites calculated by averaging data over periods when both modes are present at the same time more effectively describe the associated weather patterns. Results reveal that the high-latitude response to the MJO varies with ENSO over all longitudes, but especially across the North Pacific Rim, North America, and the North Atlantic. Further analysis demonstrates that the MJO influence on indexes of the North Atlantic Oscillation is greatest during La Niña conditions or during periods of rapid adjustment in the phase of ENSO.

El Niño-Southern Oscillation signal in the world's highest-elevation tree-ring chronologies from the Altiplano, Central Andes

2009 ◽  
Vol 281 (3-4) ◽  
pp. 309-319 ◽  
Author(s):  
Duncan A. Christie ◽  
Antonio Lara ◽  
Jonathan Barichivich ◽  
Ricardo Villalba ◽  
Mariano S. Morales ◽  
...  
Keyword(s):  
Tree Ring ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Central Andes ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation

scholarly journals Strength Outlooks for the El Niño–Southern Oscillation

2019 ◽  
Vol 34 (1) ◽  
pp. 165-175 ◽  
Author(s):  
Michelle L. L’Heureux ◽  
Michael K. Tippett ◽  
Ken Takahashi ◽  
Anthony G. Barnston ◽  
Emily J. Becker ◽  
...  
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Added Value ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
New Approach ◽  
The North ◽  
Probabilistic Forecasts ◽  
New Strategy

Abstract Three strategies for creating probabilistic forecast outlooks for El Niño–Southern Oscillation (ENSO) are compared. One is subjective and is currently used by the NOAA/Climate Prediction Center (CPC) to produce official ENSO outlooks. A second is purely objective and is based on the North American Multimodel Ensemble (NMME). A new third strategy is proposed in which the forecaster only provides the expected value of the Niño-3.4 index, and then categorical probabilities are objectively determined based on past skill. The new strategy results in more confident probabilities compared to the subjective approach and higher verification scores, while avoiding the significant forecast busts that sometimes afflict the NMME-based objective approach. The higher verification scores of the new strategy appear to result from the added value that forecasters provide in predicting the mean, combined with more reliable representations of uncertainty, which is difficult to represent because forecasters often assume less confidence than is justified. Moreover, the new approach can produce higher-resolution probabilistic forecasts that include ENSO strength information and that are difficult, if not impossible, for forecasters to produce. To illustrate, a nine-category ENSO outlook based on the new strategy is assessed and found to be skillful. The new approach can be applied to other outlooks where users desire higher-resolution probabilistic forecasts, including the extremes.

scholarly journals Influence of Modes of Climate Variability on Global Precipitation Extremes

2010 ◽  
Vol 23 (23) ◽  
pp. 6248-6262 ◽  
Author(s):  
Jesse Kenyon ◽  
Gabriele C. Hegerl
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Precipitation Extremes ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Northern Annular Mode ◽  
The North ◽  
The Pacific ◽  
The North Atlantic Oscillation

Abstract The probability of climate extremes is strongly affected by atmospheric circulation. This study quantifies the worldwide influence of three major modes of circulation on station-based indices of intense precipitation: the El Niño–Southern Oscillation, the Pacific interdecadal variability as characterized by the North Pacific index (NPI), and the North Atlantic Oscillation–Northern Annular Mode. The study examines which stations show a statistically significant (5%) difference between the positive and negative phases of a circulation regime. Results show distinct regional patterns of response to all these modes of climate variability; however, precipitation extremes are most substantially affected by the El Niño–Southern Oscillation. The effects of the El Niño–Southern Oscillation are seen throughout the world, including in India, Africa, South America, the Pacific Rim, North America, and, weakly, Europe. The North Atlantic Oscillation has a strong, continent-wide effect on Eurasia and affects a small, but not negligible, percentage of stations across the Northern Hemispheric midlatitudes. This percentage increases slightly if the Northern Annular Mode index is used rather than the NAO index. In that case, a region of increase in intense precipitation can also be found in Southeast Asia. The NPI influence on precipitation extremes is similar to the response to El Niño, and strongest in landmasses adjacent to the Pacific. Consistently, indices of more rare precipitation events show a weaker response to circulation than indices of moderate extremes; the results are quite similar, but of opposite sign, for negative anomalies of the circulation indices.

scholarly journals The impact of El Niño-Southern Oscillation on the Canadian climate

2006 ◽  
Vol 6 ◽  
pp. 149-153 ◽  
Author(s):  
A. Shabbar
Keyword(s):  
North American ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Cold Season ◽  
Tropical Pacific ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
The North ◽  
The Impact

Abstract. The quasi-periodic El Niño -Southern Oscillation (ENSO) phenomenon in the tropical Pacific Ocean produces the largest interannual variation in the cold season climate of Canada. The diabatic heating in the eastern tropical Pacific, associated with the warm phase of ENSO (El Niño), triggers Rossby waves which in turn gives rise to the Pacific-North American teleconnection (PNA) over the North American sector. The strongest cell of the PNA pattern lies over western Canada. In most of southern Canada, mean winter temperature distribution is shifted towards warmer values, and precipitation is below normal. The presence of El Niño provides the best opportunity to make skillful long-range winter forecast for Canada. A strong El Niño event, while bringing respite from the otherwise cold winter in Canada, can be expected to cost the Canadian economy two to five billion dollars.

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