scholarly journals Forecasting regional sea surface temperatures in the tropical Pacific by neural network models, with wind stress and sea level pressure as predictors

1998 ◽  
Vol 103 (C4) ◽  
pp. 7511-7522 ◽  
Author(s):  
Fredolin T. Tangang ◽  
William W. Hsieh ◽  
Benyang Tang
Keyword(s):  
Neural Network ◽  
Sea Level ◽  
Wind Stress ◽  
Network Models ◽  
Tropical Pacific ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Neural Network Models ◽  
Sea Level Pressure ◽  
The Tropical Pacific

scholarly journals Forecasts of Tropical Pacific Sea Surface Temperatures by Neural Networks and Support Vector Regression

2009 ◽  
Vol 2009 ◽  
pp. 1-13 ◽  
Author(s):  
Silvestre Aguilar-Martinez ◽  
William W. Hsieh
Keyword(s):  
Neural Network ◽  
Support Vector Regression ◽  
Tropical Pacific ◽  
Sea Surface ◽  
Water Volume ◽  
Support Vector ◽  
Neural Network Models ◽  
Error Norm ◽  
Sst Anomalies ◽  
The Tropical Pacific

Two nonlinear regression methods, Bayesian neural network (BNN) and support vector regression (SVR), and linear regression (LR), were used to forecast the tropical Pacific sea surface temperature (SST) anomalies at lead times ranging from 3 to 15 months, using sea level pressure (SLP) and SST as predictors. Datasets for 1950–2005 and 1980–2005 were studied, with the latter period having the warm water volume (WWV) above the 20∘C isotherm integrated across the equatorial Pacific available as an extra predictor. The forecasts indicated that the nonlinear structure is mainly present in the second PCA (principal component analysis) mode of the SST field. Overall, improvements in forecast skills by the nonlinear models over LR were modest. Although SVR has two structural advantages over neural network models, namely (a) no multiple minima in the optimization process and (b) an error norm robust to outliers in the data, it did not give better overall forecasts than BNN. Addition of WWV as an extra predictor generally increased the forecast skills slightly; however, the influence of WWV on SST anomalies in the tropical Pacific appears to be linear.

scholarly journals Decadal Sea Level Variability in the Pacific Ocean: Origins and Climate Mode Contributions

2019 ◽  
Vol 36 (4) ◽  
pp. 689-698 ◽  
Author(s):  
Lingsheng Meng ◽  
Wei Zhuang ◽  
Weiwei Zhang ◽  
Angela Ditri ◽  
Xiao-Hai Yan
Keyword(s):  
Pacific Ocean ◽  
Sea Level ◽  
Time Scales ◽  
Wind Stress ◽  
Tropical Pacific ◽  
Central Basin ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Sea Level Variations ◽  
The Tropical Pacific

AbstractSea level changes within wide temporal–spatial scales have great influence on oceanic and atmospheric circulations. Efforts have been made to identify long-term sea level trend and regional sea level variations on different time scales. A nonuniform sea level rise in the tropical Pacific and the strengthening of the easterly trade winds from 1993 to 2012 have been widely reported. It is well documented that sea level in the tropical Pacific is associated with the typical climate modes. However, sea level change on interannual and decadal time scales still requires more research. In this study, the Pacific sea level anomaly (SLA) was decomposed into interannual and decadal time scales via an ensemble empirical mode decomposition (EEMD) method. The temporal–spatial features of the SLA variability in the Pacific were examined and were closely associated with climate variability modes. Moreover, decadal SLA oscillations in the Pacific Ocean were identified during 1993–2016, with the phase reversals around 2000, 2004, and 2012. In the tropical Pacific, large sea level variations in the western and central basin were a result of changes in the equatorial wind stress. Moreover, coherent decadal changes could also be seen in wind stress, sea surface temperature (SST), subtropical cells (STCs), and thermocline depth. Our work provided a new way to illustrate the interannual and decadal sea level variations in the Pacific Ocean and suggested a coupled atmosphere–ocean variability on a decadal time scale in the tropical region with two cycles from 1993 to 2016.

scholarly journals Contribution of buoyancy fluxes to tropical Pacific sea level variability

2021 ◽  
Author(s):  
Patrick Wagner ◽  
Markus Scheinert ◽  
Claus W. Böning
Keyword(s):  
Sea Level ◽  
Fresh Water ◽  
Wind Stress ◽  
Tropical Pacific ◽  
Water Fluxes ◽  
Sea Level Variability ◽  
Steric Sea Level ◽  
Enso Events ◽  
Stress Changes ◽  
The Tropical Pacific

Abstract. Regional anomalies of steric sea level are either due to redistribution of heat and freshwater anomalies or due to ocean-atmosphere buoyancy fluxes. Interannual to decadal variability in sea level across the tropical Pacific is mainly due to steric variations driven by wind stress anomalies. The importance of air--sea buoyancy fluxes is less clear. We use a global, eddy permitting ocean model and a series of sensitivity experiments with quasi-climatological momentum and buoyancy fluxes to identify the contribution of buoyancy fluxes for interannual to decadal sea level variability in the tropical Pacific. We find their contribution on interannual timescales to be strongest in the central tropical Pacific at around 10° latitude in both hemispheres and also relevant in the very east of the tropical domain. Buoyancy flux forced anomalies are in phase with variations driven by wind stress changes but their effect on the prevailing anomalies and the importance of heat and fresh water fluxes vary locally. In the eastern tropical basin interannual sea level variability is amplified by anomalous heat fluxes, while the importance of fresh water fluxes is small and neither has any impact on decadal timescales. In the western tropical Pacific the variability on interannual and decadal timescales is dampened by both, heat and freshwater fluxes. The mechanism involves westward propagating Rossby waves that are triggered during ENSO events by anomalous buoyancy fluxes in the central tropical Pacific and counteract the prevailing sea level anomalies once they reach the western part of the basin.

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