TY - JOUR
T1 - Enhanced tropical methane production in response to iceberg discharge in the North Atlantic
AU - Rhodes, Rachael H.
AU - Brook, Edward J.
AU - Chiang, John C. H.
AU - Blunier, Thomas
AU - Maselli, Olivia J.
AU - McConnell, Joseph R.
AU - Romanini, Daniele
AU - Severinghaus, Jeffrey P.
PY - 2015/5/29
Y1 - 2015/5/29
N2 - 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.
AB - 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.
U2 - 10.1126/science.1262005
DO - 10.1126/science.1262005
M3 - Article
VL - 348
SP - 1016
EP - 1019
JO - Science
JF - Science
SN - 0036-8075
IS - 6238
ER -