Below is the ascii version of the abstract for 07-174.
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A. dell'Aquila, M. Felici, V. Lucarini, P.M. Ruti, A. Speranza, R. Vitolo
Extreme value statistics of mid-latitude atmospheric variability
with present-day and increased CO2 concentration
ABSTRACT. The General Circulation Model ECHAM4.6 is run under perpetual January
conditions with two different values of CO2: the present
concentration and five times as much. For each case, time series of
two indexes of mid-latitude wave activity are computed. The mean
activity of baroclinic waves and of planetary waves decreases
slightly, following the decrease of the mean baroclinicity of the
system. Inference of extreme values is performed by estimating the
parameters of the Generalised Extreme Value (GEV) distribution from
sequences of maxima over data blocks of fixed length extracted from
the time series. The sensitivity and goodness-of-fit of the inferences
are assessed by various graphical and numerical tools. The results
reveal no marked differences in the statistics of extreme values
between the cases with 1 and 5 CO2 and also suggest that the often
invoked approach of relating changes of the extremes to changes in the
mean and standard deviation of the bulk statistics is not reliable.
Maps corresponding to the dates of the extremes (block maxima) of the
indexes show that the relative weight of the wave activity of the
Atlantic sector increases with CO2 concentration.