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Detecting Spatial Patterns with the Cumulant Function – Part 2: an Application to El Niño : Volume 15, Issue 1 (19/02/2008)

By Bernacchia, A.

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Book Id: WPLBN0003979604
Format Type: PDF Article :
File Size: Pages 9
Reproduction Date: 2015

Title: Detecting Spatial Patterns with the Cumulant Function – Part 2: an Application to El Niño : Volume 15, Issue 1 (19/02/2008)  
Author: Bernacchia, A.
Volume: Vol. 15, Issue 1
Language: English
Subject: Science, Nonlinear, Processes
Collections: Periodicals: Journal and Magazine Collection, Copernicus GmbH
Historic
Publication Date:
2008
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications

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Yiou, P., Naveau, P., Vrac, M., & Bernacchia, A. (2008). Detecting Spatial Patterns with the Cumulant Function – Part 2: an Application to El Niño : Volume 15, Issue 1 (19/02/2008). Retrieved from http://www.netlibrary.net/


Description
Description: Dipartimento di Fisica, Università La Sapienza, Roma, Italy. The spatial coherence of a measured variable (e.g. temperature or pressure) is often studied to determine the regions of high variability or to find teleconnections, i.e. correlations between specific regions. While usual methods to find spatial patterns, such as Principal Components Analysis (PCA), are constrained by linear symmetries, the dependence of variables such as temperature or pressure at different locations is generally nonlinear. In particular, large deviations from the sample mean are expected to be strongly affected by such nonlinearities. Here we apply a newly developed nonlinear technique (Maxima of Cumulant Function, MCF) for detection of typical spatial patterns that largely deviate from the mean. In order to test the technique and to introduce the methodology, we focus on the El Niño/Southern Oscillation and its spatial patterns. We find nonsymmetric temperature patterns corresponding to El Niño and La Niña, and we compare the results of MCF with other techniques, such as the symmetric solutions of PCA, and the nonsymmetric solutions of Nonlinear PCA (NLPCA). We found that MCF solutions are more reliable than the NLPCA fits, and can capture mixtures of principal components. Finally, we apply Extreme Value Theory on the temporal variations extracted from our methodology. We find that the tails of the distribution of extreme temperatures during La Niña episodes is bounded, while the tail during El Niños is less likely to be bounded. This implies that the mean spatial patterns of the two phases are asymmetric, as well as the behaviour of their extremes.

Summary
Detecting spatial patterns with the cumulant function – Part 2: An application to El Niño

Excerpt
Alexander, M. A., Blade, I., Newman, M., Lanzante, J. R., Lau, N. C., and Scott, J.D.: The atmospheric bridge: the influence of ENSO teleconnections on air-sea interaction over the global oceans, J. Climate, 15, 2205–2231, 2002.; Arfken, G.: The Method of Steepest Descents, in: Mathematical Methods for Physicists, 3rd Ed., Orlando, FL, Academic Press, 428–436, 1985.; Bernacchia, A. and Naveau, P.: Detecting spatial patterns with the cumulant function – Part 1: The theory, Nonlin. Processes Geophys., 15, 159–167, 2008.; Burgers, G. and Stephenson, D. B.: The normality of El Niño, Geophys. Res. Lett., 26, 1027–1030, 1999.; Bjerknes, J.: Atmospheric teleconnections from the equatorial Pacific, Mon. Weather Rev., 97, 163–172, 1969.; Christiansen, B.: The shortcomings of nonlinear principal component analysis in identifying circulation regimes, J. Climate, 18, 4814–4823, 2005.; Coles, S.: An introduction to statistical modeling of extreme values, Springer, Berlin, 2001.; Ghil, M. and Robertson, A. W.: Solving problems with GCMs: general circulation models and their role in the climate modeling hierarchy, in: General Circulation Model Development: Past, Present and Future, edited by: Randall, D., Academic Press, New York, 285–325, 2001.; Glantz, M. H., Katz, R. W., and Nicholls, N.: Teleconnections Linking Worldwide Climate Anomalies: Scientific Basis and Societal Impact, Camridge University Press, New York, 1991.; Harrison, D. E. and Larkin, N. K.: Three COADS sea level pressure signals: a near global El Niño composite and time-series view 1946–1993, J. Climate, 9, 3025–3055, 1996.; Hoerling, M. P., Kumar, A., and Zhong, M.: El Niño, La Niña, and the nonlinearity of their teleconnections, J. Climate, 10, 1769–1786, 1997.; Hsieh, W. W.: Nonlinear multivariate and time series analysis by neural network methods, Rev.Geophys., 42, RG1003, doi:1010.1029/2002RG000112233-243, 2004.; Hyvarinen, A. and Oja, E: Independent Component Analysis: algorithms and applications, Neural Networks, 13, 411–430, 2000.; Kenney, J. F. and Keeping, E. S.: Cumulants and the Cumulant-Generating Function, in Mathematics of Statistics, Princeton, NJ, 1951.; Lau, N. C. and Nath, M. J.: Impact of ENSO on SST variability in the North Pacific and North Atlantic: Seasonal dependence and role of extratropical sea-air coupling, J. Climate, 14, 2846–2866, 2001.; Monahan, A. H.: Nonlinear Principal Component Analysis: tropical Indo-Pacific Sea Surface Temperature and Sea Level Pressure, J. Climate, 14, 219–233, 2001.; Neelin, J. D., Latif, M., and Jin, F. F.: Dynamics of coupled ocean-atmosphere models: the tropical problem, Annu. Rev. Fluid. Mech., 26, 617–659, 1994.; Philander, S. G. H.: El Niño, La Niña, and the Southern Oscillation, Academic Press, San Diego, 1990.; Piechota, T. C. and Dracup, J. A.: Drought and regional hydrologic variation in the United States: associations with the El Niño, Water Resour. Res., 32, 1359–1373, 1996; Rencher, A. C.: Multivariate statistical inference and applications, John Wiley and Sons, New York, 1998.; Sardeshmukh, P. D., Compo, G. P., and Penland, C.: Changes of probability associated with El Niño, J. Climate, 13, 4268–4286, 2000.; Saynisch, J., Kurths, J., and Maraun, D.: A conceptual ENSO model under realistic noise forcing, Nonlin. Processes Geophys., 13, 275–285, 2006; Wyrtky, K: Water displacements in the Pacific and the genesis of El Niño cycles, J. Geophys. Res, 90, 7129–7132, 1985.

 

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