Wet periods in northeastern Brazil over the past 210 kyr linked to distant climate anomalies
Resource
Nature 432: 740-743
Journal
Nature
Journal Volume
432
Journal Issue
7018
Pages
740-743
Date Issued
2004
Author(s)
Wang, Xianfeng
Auler, Augusto S.
Lawrence Edwards, R.
Cheng, Hai
Cristalli, Patricia S.
Smart, Peter L.
Richards, David A.
Abstract
The tropics are the main source of the atmosphere's sensible and latent heat, and water vapour, and are therefore important for reconstructions of past climate. But long, accurately dated records of southern tropical palaeoclimate, which would allow the establishment of climatic connections to distant regions, have not been available. Here we present a 210,000-year (210-kyr) record of wet periods in tropical northeastern Brazil-a region that is currently semi-arid. The record is obtained from speleothems and travertine deposits that are accurately dated using the U/Th method. We find wet periods that are synchronous with periods of weak East Asian summer monsoons, cold periods in Greenland, Heinrich events in the North Atlantic and periods of decreased river runoff to the Cariaco basin. We infer that the wet periods may be explained with a southward displacement of the Intertropical Convergence Zone. This widespread synchroneity of climate anomalies suggests a relatively rapid global reorganization of the ocean-atmosphere system. We conclude that the wet periods probably affected rainforest distribution, as plant fossils show that forest expansion occurred during these intermittent wet intervals, and opened a forest corrido between the Amazonian and Atlantic rainforests.
SDGs
Other Subjects
Atmospherics; Climate change; Forestry; Vapors; Latent heats; Palaeoclimate; Wet periods; Tropics; water; atmosphere-ocean system; paleoclimate; precipitation intensity; Quaternary; accuracy; analytic method; article; Asia; atmosphere; Brazil; climate change; cold; Iceland; priority journal; recording; river; sea; semiarid climate; summer; tropics; Atmosphere; Biodiversity; Brazil; Fossils; History, Ancient; Oceans and Seas; Rain; Seasons; Temperature; Trees; Tropical Climate; Water Movements; Weather; Wind; Atmosphere; Climates; Forestry; Tropics; Water Vapor; Brazil; South America; Western Hemisphere; World
Type
journal article
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