Seminario Prof. C.FIELD, 5 maggio 2003

[Patrizia Piacentini <piacent@stat.unipd.it>]

  UNIVERSITA' DEGLI  STUDI  DI PADOVA
  DIPARTIMENTO DI SCIENZE STATISTICHE
     Via C. Battisti, 241 - padova

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              Seminario

    MODELING EXTREME OCEANIC WINDS
        USING GH-DISTRIBUTION

       Prof. CHRISTOPHER FIELD
     Dalhousie University, Canada

          Lunedi' 5  maggio
              ore 14:30
            Aula  Cucconi

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Abstract

Near-surface wind data of the global ocean are used for weather and climate
prediction. Data may be obtained from various sources: moored buoys, ships,
weather stations, and satellites. Not all data is of good quality however
and models must be derived for data validation. We consider a number of
approaches for modeling the distribution of the extreme winds either using
weekly maxima or peaks over threshold. We use good quality data from
Pacific buoys both in the Tropics and in mid-latitudes. Our aim is to find
a robust model which gives good fits to the data and provides a mechanism
for identifying outliers. This becomes important with the move toward using
satellite data to estimate oceanic winds. We use the gh-distribution
developed by Tukey to model the upper tails of the extreme windspeeds and
compare its performance with the usual generalized extreme value
distribution for weekly maxima and the generalized Pareto for peaks over
thresholds. We then consider a generalization of the gh-distribution to the
multivariate case to handle winds from several buoys simultaneously. 

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Patrizia Piacentini
Segreteria  Organizzativa  Convegni e Seminari
Dipartimento di Scienze Statistiche
Università degli Studi di Padova
Via C. Battisti, 241
35121 Padova

tel 049 8274167
fax 049 8274170
e-mail segrorg@stat.unipdit
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