Enhanced tropical methane production in response to iceberg discharge in the North Atlantic

TitleEnhanced tropical methane production in response to iceberg discharge in the North Atlantic
Publication TypeJournal Article
Year of Publication2015
AuthorsRhodes R.H, Brook E.J, Chiang J.CH, Blunier T., Maselli O.J, McConnell J.R, Romanini D., Severinghaus JP
JournalScience
Volume348
Pagination1016-1019
Date Published2015/05
Type of ArticleArticle
ISBN Number0036-8075
Accession NumberWOS:000355276600044
Keywordsatmospheric methane; chronology; climate-change; greenland; hulu cave; ice; ice core; intertropical convergence zone; last glacial period; monsoon; records
Abstract

The causal mechanisms responsible for the abrupt climate changes of the Last Glacial Period remain unclear. One major difficulty is dating ice-rafted debris deposits associated with Heinrich events: Extensive iceberg influxes into the North Atlantic Ocean linked to global impacts on climate and biogeochemistry. In a new ice core record of atmospheric methane with ultrahigh temporal resolution, we find abrupt methane increases within Heinrich stadials 1, 2, 4, and 5 that, uniquely, have no counterparts in Greenland temperature proxies. Using a heuristic model of tropical rainfall distribution, we propose that Hudson Strait Heinrich events caused rainfall intensification over Southern Hemisphere land areas, thereby producing excess methane in tropical wetlands. Our findings suggest that the climatic impacts of Heinrich events persisted for 740 to 1520 years.

DOI10.1126/science.1262005
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