Dynamics of Precipitation Anomalies in Tropical South America

Abstract

In this study, precipitation in Tropical South America in the 1931–2016 period is investigated by means of Principal Component Analysis and composite analysis of circulation fields. The associated dynamics are analyzed using the 20th century ERA-20C reanalysis. It is found that the main climatic processes related to precipitation anomalies in Tropical South America are: (1) the intensity and position of the South Atlantic Convergence Zone (SACZ); (2) El Niño Southern Oscillation (ENSO); (3) the meridional position of the Intertropical Convergence Zone (ITCZ), which is found to be related to Atlantic Sea Surface Temperature (SST) anomalies; and (4) anomalies in the strength of the South American Monsoon System, especially the South American Low-Level Jet (SALLJ). Interestingly, all of the analyzed anomalies are related to processes that operate from the Atlantic Ocean, except for ENSO. Results from the present study are in agreement with the state of the art literature about precipitation anomalies in the region. However, the added strength of the longer dataset and the larger study area improves the knowledge and gives new insights into how climate variability and the resulting dynamics are related to precipitation in Tropical South America.

Drivers of δ18O Variability Preserved in Ice Cores From Earth's Highest Tropical Mountain

“…During the CB wet season (October through April), a pressure cell known as the Azores High directs northeasterly winds carrying water vapor across the South American continent (Figure 1). The southward migration of the ITCZ is linked to warmer SSTs in the South Atlantic Ocean (Córdova et al., 2022) and further channels moist air to the Chaco Low, which is associated with an upper level anticyclone (the Bolivian High; Figueroa et al., 1995; Junquas et al., 2018) that diverts moist air westward to the Andes (Valdivielso et al., 2020). Roughly 90% of the total annual precipitation in the CB is generated during the wet season (Vuille et al., 2008), leaving May through September considerably drier.…”

Analysis of Household Daily Water Consumption Dynamics in the Tropical Environment

“…Detailed and comprehensive knowledge of daily water use variations at household level is significant to the predictability of weekly, monthly, and/or annual levels of water usage [ 3 , 14 , 26 ]. Such knowledge will enhance optimization of the use of water, prediction modelling, policy direction, and effective planning for sustainable living [ 5 , 27 , 28 ]. Tropical region is characterized with climate and weather variabilities which strongly influence water demand in time [ 20 , 29 , 30 ].…”

“…Time-use theory in this context emphasizes the allocation of time among different home activities, including household chores and water-related tasks [ 38 , 39 ]. This theory explores how individuals prioritize and distribute their time throughout the day and how it impacts water use patterns [ 27 , 37 ]. Factors such as the availability of water-related appliances, the time required for various water-related tasks, and the timing of activities can affect daily water use.…”