scholarly journals Pacific Decadal Variability and Central Pacific Warming El Niño in a Changing Climat

2016 ◽  
Author(s):  
Niklas Schneider ◽  
E. Di Lorenzo ◽  
K. Cobb ◽  
B. T. Anderson ◽  
D. J. Vimont
Keyword(s):  
El Niño ◽  
Decadal Variability ◽  
El Nino ◽  
Central Pacific ◽  
Pacific Decadal Variability ◽  
Central Pacific Warming

ENSO-Like and ENSO-Induced Tropical Pacific Decadal Variability in CGCMs

2013 ◽  
Vol 26 (5) ◽  
pp. 1485-1501 ◽  
Author(s):  
Jung Choi ◽  
Soon-Il An ◽  
Sang-Wook Yeh ◽  
Jin-Yi Yu
Keyword(s):  
El Niño ◽  
Decadal Variability ◽  
El Nino ◽  
Tropical Pacific ◽  
Modulation Index ◽  
Subsurface Temperature ◽  
Enso Variability ◽  
Decadal Modulation ◽  
Pacific Decadal Variability ◽  
La Nina

Abstract Outputs from coupled general circulation models (CGCMs) are used in examining tropical Pacific decadal variability (TPDV) and their relationships with El Niño–Southern Oscillation (ENSO). Herein TPDV is classified as either ENSO-induced TPDV (EIT) or ENSO-like TPDV (ELT), based on their correlations with a decadal modulation index of ENSO amplitude and spatial pattern. EIT is identified by the leading EOF mode of the low-pass filtered equatorial subsurface temperature anomalies and is highly correlated with the decadal ENSO modulation index. This mode is characterized by an east–west dipole structure along the equator. ELT is usually defined by the first EOF mode of subsurface temperature, of which the spatial structure is similar to ENSO. Generally, this mode is insignificantly correlated with the decadal modulation of ENSO. EIT closely interacts with the residuals induced by ENSO asymmetries, both of which show similar spatial structures. On the other hand, ELT is controlled by slowly varying ocean adjustments analogous to a recharge oscillator of ENSO. Both types of TPDV have similar spectral peaks on a decadal-to-interdecadal time scale. Interestingly, the variances of both types of TPDV depend on the strength of connection between El Niño–La Niña residuals and EIT, such that the strong two-way feedback between them enhances EIT and reduces ELT. The strength of the two-way feedback is also related to ENSO variability. The flavors of El Niño–La Niña with respect to changes in the tropical Pacific mean state tend to be well simulated when ENSO variability is larger in CGCMs. As a result, stronger ENSO variability leads to intensified interactive feedback between ENSO residuals and enhanced EIT in CGCMs.

Interdecadal Amplitude Modulation of El Niño–Southern Oscillation and Its Impact on Tropical Pacific Decadal Variability*

2013 ◽  
Vol 26 (18) ◽  
pp. 7280-7297 ◽  
Author(s):  
Tomomichi Ogata ◽  
Shang-Ping Xie ◽  
Andrew Wittenberg ◽  
De-Zheng Sun
Keyword(s):  
Amplitude Modulation ◽  
El Niño ◽  
Decadal Variability ◽  
El Nino ◽  
Southern Oscillation ◽  
Tropical Pacific ◽  
Sea Surface ◽  
El Nino Southern Oscillation ◽  
Pacific Decadal Variability ◽  
Decadal Scale

Abstract The amplitude of El Niño–Southern Oscillation (ENSO) displays pronounced interdecadal modulations in observations. The mechanisms for the amplitude modulation are investigated using a 2000-yr preindustrial control integration from the Geophysical Fluid Dynamics Laboratory Climate Model, version 2.1 (GFDL CM2.1). ENSO amplitude modulation is highly correlated with the second empirical orthogonal function (EOF) mode of tropical Pacific decadal variability (TPDV), which features equatorial zonal dipoles in sea surface temperature (SST) and subsurface temperature along the thermocline. Experiments with an ocean general circulation model indicate that both interannual and decadal-scale wind variability are required to generate decadal-scale tropical Pacific temperature anomalies at the sea surface and along the thermocline. Even a purely interannual and sinusoidal wind forcing can produce substantial decadal-scale effects in the equatorial Pacific, with SST cooling in the west, subsurface warming along the thermocline, and enhanced upper-ocean stratification in the east. A mechanism is proposed by which residual effects of ENSO could serve to alter subsequent ENSO stability, possibly contributing to long-lasting epochs of extreme ENSO behavior via a coupled feedback with TPDV.

scholarly journals Interannual and Decadal Variability in Tropical Pacific Chlorophyll from a Statistical Reconstruction: 1958–2008

2017 ◽  
Vol 30 (18) ◽  
pp. 7293-7315 ◽  
Author(s):  
Stephanie Schollaert Uz ◽  
Antonio J. Busalacchi ◽  
Thomas M. Smith ◽  
Michael N. Evans ◽  
Christopher W. Brown ◽  
...  
Keyword(s):  
El Niño ◽  
Decadal Variability ◽  
El Nino ◽  
Southern Oscillation ◽  
Ocean Color ◽  
Sea Surface ◽  
Central Pacific ◽  
Central Pacific El Niño ◽  
Equatorial Undercurrent ◽  
Statistical Reconstruction

Abstract Historical understanding of marine biological dynamics has been limited by sparse in situ observations and the fact that dedicated ocean color satellite remote sensing only began in 1997. From these observations, it has become clear that physical oceanography controls biological variability over seasonal to interannual time scales. To quantify how multidecadal, climate-scale patterns impact biological productivity, the strong correlation with sea surface temperature and sea surface height is utilized to reconstruct a retrospective 51-yr time series of surface chlorophyll, the pigment measured by ocean color satellites. The canonical correlation analysis statistical reconstruction demonstrates greatest skill away from land and within about 10° of the equator where chlorophyll variance is greatest and predominantly associated with El Niño–Southern Oscillation dynamics. Differences in chlorophyll patterns between east or central Pacific El Niño events are observed, with larger declines east of 180° for east Pacific events and west of 180° for central Pacific events. Additionally, small but significant decadal variations in chlorophyll patterns are observed corresponding to the Pacific decadal oscillation. Decadal changes in chlorophyll west of 180° are consistent with increased stratification, whereas changes between 110°–140°W may be related to long-term shoaling of the nutrient-bearing equatorial undercurrent.

scholarly journals Asymmetric Modulation of El Niño and La Niña and the Linkage to Tropical Pacific Decadal Variability

2017 ◽  
Vol 30 (12) ◽  
pp. 4705-4733 ◽  
Author(s):  
Yuko M. Okumura ◽  
Tianyi Sun ◽  
Xian Wu
Keyword(s):  
El Niño ◽  
Decadal Variability ◽  
El Nino ◽  
Southern Oscillation ◽  
Tropical Pacific ◽  
La Niña ◽  
Climate System Model ◽  
Pacific Decadal Variability ◽  
La Nina ◽  
Leading Mode

El Niño–Southern Oscillation (ENSO) in a 1300-yr preindustrial control simulation of the Community Climate System Model, version 4 (CCSM4), exhibits distinct modulation in association with tropical Pacific decadal variability (TPDV). The frequency and duration of El Niño events modulate with changes in the interbasin sea surface temperature (SST) gradient related to the leading mode of TPDV, which resembles the interdecadal Pacific oscillation (IPO). La Niña shows similar changes with the IPO but is also controlled by changes in El Niño that often precedes La Niña, and these effects tend to cancel each other. The amplitude of ENSO, on the other hand, is closely related to the second leading mode of TPDV that affects the zonal and meridional contrast of tropical Pacific climate. Significant changes in the pattern and seasonal evolution related to this TPDV mode are found mainly for El Niño because of the nonlinear relation between the atmospheric deep convection and SSTs. The resultant changes in the amplitude of El Niño, in turn, affect the amplitude and duration of the following La Niña, as well as the asymmetry in their patterns and duration. The decadal ENSO modulation associated with both TPDV modes is not symmetrical between El Niño and La Niña and thus is not likely to occur solely as a result of random variability. The patterns of TPDV in CCSM4 have resemblance to those simulated by its atmospheric component coupled to a slab ocean model, suggesting that TPDV induced by stochastic atmospheric variability interacts with the ENSO dynamics.

Tropical Pacific Decadal Variability Induced by Nonlinear Rectification of El Niño–Southern Oscillation

2020 ◽  
Vol 33 (17) ◽  
pp. 7289-7302
Author(s):  
Geon-Il Kim ◽  
Jong-Seong Kug
Keyword(s):  
El Niño ◽  
Decadal Variability ◽  
El Nino ◽  
Southern Oscillation ◽  
Tropical Pacific ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Coupled Models ◽  
Pacific Decadal Variability ◽  
Dipole Pattern

AbstractOn the basis of 32 long-term simulations with state-of-the-art coupled GCMs, we investigate the relationship between tropical Pacific decadal variability (TPDV) and El Niño–Southern Oscillation (ENSO). The first empirical orthogonal function (EOF) mode for the 11-yr moving sea surface temperatures (SSTs) in the coupled models is commonly characterized by El Niño–like decadal variability with Bjerknes air–sea interaction. However, the second EOF mode can be separated into two groups, such that 1) some models have a zonal dipole SST pattern and 2) other models are characterized by a meridional dipole pattern. We found that models with the zonal dipole pattern in the second mode tend to simulate strong ENSO amplitude and asymmetry in comparison with those of the other models. Also, the residual patterns, which are defined as the summation of El Niño and La Niña SST composite anomalies, are very similar to the decadal dipole pattern, which suggests that ENSO residuals can cause the dipole decadal variability. It is found that decadal modulation of ENSO variability in these models strongly depends on the phase of the dipole decadal variability. The decadal changes in ENSO residual correspond well with the decadal changes in the dipole pattern, and the nonlinear dynamic heating terms by ENSO anomalies are well matched with the decadal dipole pattern.

Contrasting effects of the El Niño 2015–16 event on coral reefs from the central pacific coast of Mexico

2021 ◽  
Vol 42 (2) ◽  
Author(s):  
Héctor Nava ◽  
Norma López ◽  
Pedro Ramírez‐García ◽  
Elizabeth Garibay‐Valladolid
Keyword(s):  
Coral Reefs ◽  
El Niño ◽  
Pacific Coast ◽  
El Nino ◽  
Central Pacific
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