Weather types for the seasonal transitions in Central America

 

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Detalles Bibliográficos
Autores: Sáenz Soto, Fernán, Alfaro Martínez, Eric J., Hidalgo León, Hugo G.
Formato: artículo original
Fecha de Publicación:2023
Descripción:Unsupervised learning techniques are employed to study the relationship be tween atmospheric circulation and precipitation over Central America and its surrounding areas. Specifically, the clustering algorithm k-means++ is applied to three coarse-grained datasets from ERA-interim reanalysis that are the candidates for representing the atmospheric state vector, each candi date contains its full temporal variability. Datasets are composed of: a) wind fields at 925, 800 and 200 hPa, b) same as “a)” plus convective available po tential energy and c) same as “a)” plus total column water vapor. Clustering metrics, namely the variance ratio criterion, the silhouette criterion and the mean squared error, are computed to quantify clustering quality. Clusters are interpreted as weather types, recurrent configurations of the atmospheric state vector associated with observable weather states. The correct number of clusters for each dataset is determined with a Monte Carlo test of nor mality, to assure cluster existence. The main objective is to obtain a set of weather types containing elements that characterize the transition from and to the rainy season over the Pacific side of Central America as well as other elements of the seasonal cycle of regional precipitation, such as the Mid-Summer Drought. Besides the statistical metrics, in order to select be tween candidate datasets and plausible number of clusters, focus is given to the temporal characteristics of the clusters. Existing literature does not provide a set of weather types suitable to analyze seasonal transitions and the differences in the mechanisms associated with rainfall maxima
País:Kérwá
Institución:Universidad de Costa Rica
Repositorio:Kérwá
Lenguaje:Inglés
OAI Identifier:oai:kerwa.ucr.ac.cr:10669/91245
Acceso en línea:https://hdl.handle.net/10669/91245
Palabra clave:CENTRAL AMERICA
PRECIPITATION
WEATHER TYPES
CLUSTER ANALYSIS
SEASONAL CLIMATE VARIABILITY
AMÉRICA CENTRAL
PRECIPITACIÓN
TIPOS DE TIEMPO ATMOSFÉRICO
ANÁLISIS DE CONGLOMERADOS
VARIABILIDAD CLIMÁTICA ESTACIONAL