Covariability of the Southern Westerlies and atmospheric CO2 during the Holocene
Year: 2010
Type: article
Abstract: A suite of mechanisms has been proposed to account for natural variations in atmospheric \nCO2 during the Holocene; all of which have achieved limited success in reproducing the timing, \ndirection, and magnitude of change. Recent modeling studies propose that changes in the \nlatitudinal position and strength of the Southern Hemisphere Westerly Winds (SWW) can \ngreatly infl uence large-scale ocean circulation and degassing of the deep ocean via changes in \nwind-driven upwelling in the Southern Ocean. The extent to which the hypothesized SWW– \nSouthern Ocean coupled system could account for changes in atmospheric CO2 is uncertain, \nbecause of a lack of observations on the behavior of the SWW in the past, the paucity of appropriate \nrecords of productivity changes in the Southern Ocean, and our limited understanding \nof the sensitivity of the Southern Ocean biological and/or physical system to SWW forcing. \nHere we report a reconstruction of the behavior of the SWW during the past 14 k.y. based \non terrestrial ecosystem proxies from western Patagonia, South America. The reconstructed \nvariations in the intensity of zonal fl ow correspond to the timing and structure of atmospheric \nCO2 changes, and are consistent with the modeled magnitude of CO2 changes induced by \nvarying strengths of the SWW. The close match between data and models supports the view \nthat the SWW–Southern Ocean coupled system underpins multimillennial CO2 variations \nduring the current interglacial and, possibly, during glacial cycles over the past 800 k.y.
Source: Geology
DOI: 10.1130/g30962.1
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
SDG: Climate action
Open Access status: green
OpenAlex ID: W2007407141