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Explorador del Atlas de Sequías de Sudamérica, https://sada.cr2.cl. Centro de Ciencia del Clima y la Resiliencia (CR)²
Abstract
https://sada.cr2.cl /
Este Explorador WEB se basa en los datos de la publicación de la reconstrucción de aridez de Sudamérica (scPDSI) utilizando anillos de árboles https://doi.org/10.1073/pnas.2002411117. A través de el es posible visualizar mapas anuales de aridez, calcular mapas promedio de grupos de años, mapas de correlación con otras variables, y extracción de series de tiempo de índices y parámetros de aridez para territorios y regiones particulares de Sudamérica a partir del año 1400. contacto:duncanchristieb@gmail.com
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Content uploaded by Duncan A. Christie
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... This deposit is dated 1664 ± 562 AD and could correspond to a humid phase developed between 1550 and 1650 AD, related to the Little Ice Age. This period was characterized by a southern displacement of ITCZ from the mean position, increasing the precipitation southward [106], it is reported in a study based on tree rings reconstruction [107] and the public database SADA (South American Drought Atlas, https://sada.cr2.cl/?fbclid=IwAR0fiTvBJWH76A-pQjQKS3WLyEti68GOZpROKvIb2EnesSGfotp63NzEiHQ, 15 October 2021) [108]. The increase of intense heavy rain and floods during this period strongly affected the rainfall distribution in Peru and Argentina [109][110][111]. ...
The coast of Chile has been exposed to marine submersion events from storm surges, tsunamis and flooding due to heavy rains. We present evidence of these events using sedimentary records that cover the last 1000 years in the Pachingo wetland. Two sediment cores were analyzed for granulometry, XRF, pollen, diatoms and TOC. Three extreme events produced by marine sub-mersion and three by pluvial flooding during El Niño episodes were identified. Geochronology was determined using a conventional dating method using 14 C, 210 Pbxs and 137 Cs). The older marine event (E1) was heavier, identified by a coarser grain size, high content of seashells, greater amount of gravel and the presence of two rip-up clasts, which seems to fit with the tsunami of 1420 Cal AD. The other two events (E3 and E5) may correspond to the 1922 (E3) tsunami and the 1984 (E5) storm waves, corroborated with a nearshore wave simulation model for this period (SWAM). On the other hand, the three flood events (E2, E4, E6) all occurred during episodes of El Niño in 1997 (E6), 1957 (E4) and 1600 (E6), represented by layers of fine-grain sands and wood charcoal remains.
Tropical South American climate is influenced by the South American Summer Monsoon and the El Niño Southern Oscillation. However, assessing natural hydroclimate variability in the region is hindered by the scarcity of long-term instrumental records. Here we present a tree-ring δ¹⁸O-based precipitation reconstruction for the South American Altiplano for 1700–2013 C.E., derived from Polylepis tarapacana tree rings. This record explains 56% of December–March instrumental precipitation variability in the Altiplano. The tree-ring δ¹⁸O chronology shows interannual (2–5 years) and decadal (~11 years) oscillations that are remarkably consistent with periodicities observed in Altiplano precipitation, central tropical Pacific sea surface temperatures, southern-tropical Andean ice core δ¹⁸O and tropical Pacific coral δ¹⁸O archives. These results demonstrate the value of annual-resolution tree-ring δ¹⁸O records to capture hydroclimate teleconnections and generate robust tropical climate reconstructions. This work contributes to a better understanding of global oxygen-isotope patterns, as well as atmospheric and oceanic processes across the tropics.
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