**29/04/09 - 15:30h** Ciclo de Palestras Pós Graduação em Estatística UFRJ

["Alexandra M. Schmidt" <alex@im.ufrj.br>]

Caros, 

Dando continuidade ao Ciclo de Palestras do Programa de Pós-Graduação em
Estatística do IM-UFRJ, nesta 4a feira, 29/04/09, as 15:30h, teremos a 
palestra da 

Professora Lelys Guenni (Universidad Simon-Bolivar, Caracas)

Título: Detection of oceanic influence on the precipitation of the central 
Venezuelan coast using time-varying models

O resumo segue abaixo. 

Contamos com a presenca de voces.

Acompanhem a atualizacao do programa do nosso ciclo de palestras  no sitio
www.dme.ufrj.br opcao Atividades subopcao Ciclo de Palestras.

Atenciosamente,

Alexandra

Ps.: Desculpem-me pela eventual duplicação da postagem desta mensagem.



Título: Detection of oceanic influence on the precipitation of the central 
Venezuelan coast using time-varying models


Resumo
Exceptional rainfall events occurred during mid-December 1999 produced floods 
and landslides along the north central coast of Venezuela with over 10,000 
fatalities reported and economic looses estimated at over 1.8 million (Lyon, 
2003). Similar events occurred also in February, 1951 and February 2005. 
Wieczorek et al. (2001) also reported that many of these severe events 
documented in the region have occurred during the period November-February. 
Common features of the combined anomalies in the Equatorial Pacific and the 
North Tropical Atlantic sea surface temperature (SST) were found for most of 
the extreme rainfall events. The aim of the analysis is to detect potential 
changes in mean daily precipitation and monthly daily maxima during the 
November-February months. Dependencies of extremes and mean daily values on 
the oceanic features are analyzed using time varying models. To explore 
changes in mean daily rainfall dependence on the SST anomalies, a normal 
distribution for the cubic root of mean daily rainfall with a temporal 
component defined through a Dynamic Linear model (DLM) or state space 
representation was used. On another hand, a non-stationary Generalized 
Extreme Value (GEV) model with a time-varying dependence of the location 
parameter on the oceanic anomalies, was used to evaluate monthly daily maxima 
changes with time. A more clear signal of change is observed for the extreme 
values than for the mean values, which agrees with the potential rainfall 
changes projected under climate change. 
This is joint work with Gabriel Huerta (University of New Mexico) and Bruno 
Sansó (University of California at Santa Cruz).


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Alexandra Mello Schmidt, PhD
Professora Adjunta
Instituto de Matemática - UFRJ
Departamento de Métodos Estatísticos
Caixa Postal 68530 Rio de Janeiro - RJ 
CEP:21.945-970 Brasil
Tel: 0055 21 2562 7505 Ramal (Extension) 204
Fax: 0055 21 2562 7374

http://www.dme.ufrj.br/~alex
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There is no time to lose. Cash your dreams before they slip away. 
Lose your dreams and you lose your mind.