Methods of ensemble prediction for seasonal forecasts with a coupled ocean-atmosphere model

Authors

  • Jorgen Segerlund Frederiksen CSIRO Marine and Atmospheric Research
  • Carsten Segerlund Frederiksen Centre for Australian Weather and Climate Research, Bureau of Meteorology
  • Stacey Lee Osbrough CSIRO Marine and Atmospheric Research

DOI:

https://doi.org/10.21914/anziamj.v54i0.6509

Keywords:

60G25 Prediction Theory

Abstract

Computational methods for efficient seasonal ensemble prediction with a coupled ocean-atmosphere model, consisting of a global atmosphere and a Pacific basin ocean, are described. Nonlinearly modified Lyapunov vectors, termed bred modes, and finite time normal modes, termed cyclic modes, that grow fastest over a month are found to be suitable ensemble perturbations. The skill of seasonal ensemble prediction is examined in hindcast simulations for the period 1980 to 2000. In general, ensemble mean forecasts are significantly more skilful than the control forecasts. We find that cyclic mode perturbations are generally more effective than bred vectors in improving ensemble forecasts. References

Author Biographies

Jorgen Segerlund Frederiksen, CSIRO Marine and Atmospheric Research

Jorgen Frederiksen is CSIRO Fellow and Fellow of Australian Academy of Science

Carsten Segerlund Frederiksen, Centre for Australian Weather and Climate Research, Bureau of Meteorology

Carsten Frderiksen is Senior Research Scientist and Team Leader

Stacey Lee Osbrough, CSIRO Marine and Atmospheric Research

Stacey Osbrough is Support Scientist

Published

2013-07-09

Issue

Section

Proceedings Computational Techniques and Applications Conference