TY - JOUR
T1 - Quantifying the residual effects of ENSO on low-frequency variability in the tropical Pacific
AU - Choi, Jung
AU - An, Soon Il
N1 - Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2013/3/30
Y1 - 2013/3/30
N2 - The asymmetry of El Niño-La Niña, one of the well-known characteristics of the El Niño-Southern Oscillation (ENSO), is suggested to produce a non-zero residual effect that could rectify the background state, and thereby generates the low-frequency variability in the tropical Pacific. So far, this rectification effect has been hardly quantified apart from the low-frequency variability because the low-frequency variability captured via conventional methods represents the mixture of both the residual effects of ENSO and the no-ENSO-related natural decadal variability. Here we separate the residual effects of ENSO from the natural decadal variability that appears in four historical sea surface temperature datasets during the last century by applying a long-term moving average. A significant correlation between the computed residual effect and the decadal change in the ENSO skewness (i.e. the measure of the El Niño-La Niña asymmetry) confirmed the applicability of our computational method. Quantitatively, the residual effects of ENSO consistently account for at least 15% of the total low-frequency variability in four datasets, especially over the eastern and central tropical Pacific. This implies that the asymmetry of ENSO enhances the tropical Pacific decadal variability for the last century.
AB - The asymmetry of El Niño-La Niña, one of the well-known characteristics of the El Niño-Southern Oscillation (ENSO), is suggested to produce a non-zero residual effect that could rectify the background state, and thereby generates the low-frequency variability in the tropical Pacific. So far, this rectification effect has been hardly quantified apart from the low-frequency variability because the low-frequency variability captured via conventional methods represents the mixture of both the residual effects of ENSO and the no-ENSO-related natural decadal variability. Here we separate the residual effects of ENSO from the natural decadal variability that appears in four historical sea surface temperature datasets during the last century by applying a long-term moving average. A significant correlation between the computed residual effect and the decadal change in the ENSO skewness (i.e. the measure of the El Niño-La Niña asymmetry) confirmed the applicability of our computational method. Quantitatively, the residual effects of ENSO consistently account for at least 15% of the total low-frequency variability in four datasets, especially over the eastern and central tropical Pacific. This implies that the asymmetry of ENSO enhances the tropical Pacific decadal variability for the last century.
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U2 - 10.1002/joc.3470
DO - 10.1002/joc.3470
M3 - Article
AN - SCOPUS:84874786282
VL - 33
SP - 1047
EP - 1052
JO - Journal of Climatology
JF - Journal of Climatology
SN - 0899-8418
IS - 4
ER -