Climate Dynamics

, Volume 35, Issue 5, pp 807–826

Further analysis of singular vector and ENSO predictability in the Lamont model—Part I: singular vector and the control factors

  • Yanjie Cheng
  • Youmin Tang
  • Xiaobing Zhou
  • Peter Jackson
  • Dake Chen
Article

DOI: 10.1007/s00382-009-0595-7

Cite this article as:
Cheng, Y., Tang, Y., Zhou, X. et al. Clim Dyn (2010) 35: 807. doi:10.1007/s00382-009-0595-7

Abstract

In this study, singular vector analysis was performed for the period from 1856 to 2003 using the latest Zebiak–Cane model version LDEO5. The singular vector, representing the optimal growth pattern of initial perturbations/errors, was obtained by perturbing the constructed tangent linear model of the Zebiak–Cane model. Variations in the singular vector and singular value, as a function of initial time, season, ENSO states, and optimal period, were investigated. Emphasis was placed on exploring relative roles of linear and nonlinear processes in the optimal perturbation growth of ENSO, and deriving statistically robust conclusions using long-term singular vector analysis. It was found that the first singular vector is dominated by a west–east dipole spanning most of the equatorial Pacific, with one center located in the east and the other in the central Pacific. Singular vectors are less sensitive to initial conditions, i.e., independence of seasons and decades; while singular values exhibit a strong sensitivity to initial conditions. The dynamical diagnosis shows that the total linear and nonlinear heating terms play opposite roles in controlling the optimal perturbation growth, and that the linear optimal perturbation is more than twice as large as the nonlinear one. The total linear heating causes a warming effect and controls two positive perturbation growth regions: one in the central Pacific and the other in the eastern Pacific; whereas the total linearized nonlinear advection brings a cooling effect controlling the negative perturbation growth in the central Pacific.

Keywords

ENSO Predictability Singular vector analysis 

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Yanjie Cheng
    • 1
  • Youmin Tang
    • 1
  • Xiaobing Zhou
    • 1
    • 4
  • Peter Jackson
    • 1
  • Dake Chen
    • 2
    • 3
  1. 1.Environmental Science and EngineeringUniversity of Northern British ColumbiaPrince GeorgeCanada
  2. 2.Lamont-Doherty Earth Observatory of Columbia UniversityPalisadesUSA
  3. 3.State Key Laboratory of Satellite Ocean Environment DynamicsHangzhouChina
  4. 4.Centre for Australian Weather and Climate Research (CAWCR), Bureau of MeteorologyMelbourneAustralia

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