Weather forecasts produced with numerical weather prediction (NWP) models of the
atmosphere possess intrinsic uncertainty. This uncertainty is caused through both errors in …

The deterministic equations describing the dynamics of the atmosphere (and of the climate
system) are known to display the property of sensitivity to initial conditions. In the ergodic …

Numerical weather prediction models as well as the atmosphere itself can be viewed as
nonlinear dynamical systems in which the evolution depends sensitively on the initial …

Singular vectors of the linearized equations of motion have been used to study the instability
properties of the atmosphere–ocean system and its related predictability. A third use of these …

Statistical considerations suggest that 1) even for a perfect ensemble (one in which all
sources of forecast error are sampled correctly) there need not be a high correlation …

To the extent that model error is nonnegligible in numerical models of the atmosphere, it
must be accounted for in 4D atmospheric data assimilation systems. In this study, a method …

Lyapunov vectors are natural generalizations of normal modes for linear disturbances to
aperiodic deterministic flows and offer insights into the physical mechanisms of aperiodic …

We use a simple yet Earth-like hemispheric atmospheric model to propose a new framework
for the mathematical properties of blocking events. Using finite-time Lyapunov exponents …

Predicting the future state of a turbulent dynamical system such as the atmosphere has been
recognized for several decades to be an essentially statistical undertaking. Uncertainties …

Chaos places no a priori restrictions on predictability: Any uncertainty in the initial condition
can be evolved and then quantified as a function of fore cast time. If a specified accuracy at a …