Latitudinal Profiles of Seasonal Rainfall-ENSO Association Along the Coast of Central and South America Using Time-Lagged, Three-Way Contingency Tables

• Activity Number: 363
• Type: Contributed
• Date/Time: Tuesday, August 2, 2011 : 10:30 AM to 12:20 PM
• Sponsor: Section on Statistics and the Environment
• Author(s): Luis S. Cid*+ and Sandra M. Ramirez and Eric Alfaro
• Companies: Universidad del Bio Bio and Universidad Javeriana de Cali and Universidad de Costa Rica
• Keywords: El Niño ; rainfall ; lagged category ; contingency tables

Abstract

Our primary interest is to determine the probability of occurrence of wet or dry events based on the occurrence of an El Niño event and from there define strategies according its consequences on climate. We focus on the ocean/atmosphere interaction (ENSO) time series including sea surface temperature (SST), sea level pressure (SLP) and rainfall anomalies. We categorize an ENSO index (NOS) into terciles and dry/normal/wet for rainfall. The objective is to model the relationships between the El Niño and rainfall over the west coast of Central and South America. Data consist of time series of SST, SLP and rainfall for different latitudes along the west coast of Central and South America over 2.5x2.5 degrees grid. Non symmetrical three way contingency tables were considered, including a time lagged categorization of the predictor variable (NOS). Data will be analyzed using generalized linear