Anderson, J. L., and W. F. Stern, 1996: Evaluating the potential
predictive utility of ensemble forecasts. Journal of Climate,
9(2), 260-269.
Abstract: A method is presented for determining when an ensemble
of model forecasts has the potential to provide some useful information.
An ensemble forecast of a particular scalar quantity is said to have potential
predictive utility when the ensemble forecast distribution is significantly
different from an appropriate climatological distribution. Here, the potential
predictive utility is measured using Kuiper's statistical test for comparing
two discrete distributions. More traditional measures of the potential
usefulness of an ensemble forecast based on ensemble mean or variance discard
possibly valuable information by making implicit assumptions about the
distributions being compared.
Application of the potential predictive utility to long integrations of
an atmospheric general circulation model in a boundary value problem (an
ensemble of Atmospheric Model Intercomparison Project integrations) reveals
a number of features about the response of a GCM to observed sea surface
temperatures. In particular, the ensemble of forecasts is found to have
potential predictive utility over large geographic areas for a number of
atmospheric fields during strong El Niño-Southern Oscillation anomalous
events. Unfortunately, there are only limited areas of potential predictive
utility for near-surface fields and precipitation outside the regions of
the tropical oceans. Nevertheless, the method presented here can identify
all areas where the GCM ensemble may provide useful information, whereas
methods that make assumptions about the distribution of the ensemble forecast
variables may not be able to do so.