doctoralThesis
Dynamics of Precipitation Anomalies in Tropical South America: A Multiscale Approach
Fecha
2023-05-08Autor
Córdova Mora, Mario Andrés
Institución
Resumen
This PhD thesis aims to study the dynamics of precipitation anomalies and extreme precipitation
events in tropical South America (TrSA). Precipitation anomalies in TrSA are influenced by a
complex climate variability resulting from the superposition of various phenomena acting on
different temporal and spatial scales, as well as several geographical features. The study uses
interpolated gridded global datasets and climate reanalysis to understand dynamics of
precipitation anomalies, while weather radar data and last-generation reanalysis datasets were
employed to investigate extreme precipitation events. The study applied data analysis
techniques and machine learning algorithms and incorporated process knowledge to select the
input data and interpret the results. Three objectives were executed to understand precipitation
anomalies and extreme precipitation events in TrSA using a multiscale perspective: 1)
understanding the dynamics of precipitation anomalies in tropical South America in annual to
monthly scales, 2) understanding the dynamics of precipitation anomalies in the tropical Andes
in seasonal scale, and 3) understanding the dynamics of extreme precipitation at event scale in
the southern Ecuadorian Andes. The study found that precipitation anomalies are mainly
influenced by the intensity and position of the South Atlantic Convergence Zone (SACZ), El
Niño Southern Oscillation (ENSO), the meridional position of the Intertropical Convergence
Zone (ITCZ), and the strength of the South American Monsoon System. Moreover, Convective
Available Potential Energy (CAPE), the vertical integral of divergence of moisture flux, and SSTbased
oceanic indices were found to be important variables that influence precipitation
anomalies in different regions of the tropical Andes. Finally, the study found distinct patterns of
circulation anomalies for extreme events in the southern Ecuadorian Andes.