Title: On ensemble forecasts, singular vectors and reliability

Authors: Martin Leutbecher (ECMWF)

Perturbations of the initial conditions based on the leading singular vectors of the forecast model propagator are used to represent initial uncertainties in some ensemble prediction systems. The presentation will reflect on the rationale for this approach and the implications it has for the reliability of the ensemble forecasts, i.e. their statistical consistency. A comparison of ensemble variance with the variance of the ensemble mean error in the subspaces defined by the leading evolved singular vectors will play a key role for evaluating and understanding the representation of initial uncertainties.

GMAO Head: Michele Rienecker Global Modeling and Assimilation Office NASA Goddard Space Flight Center

Curator: Nikki Privé Last Updated: May 27 2011