Variation of CH4 concentrations recorded in Dunde ice core bubbles

Detailed insight into natural variations of the greenhouse gas nitrous oxide (N2O) in response to changes in the Earth's climate system is provided by new measurements along the ice core of the North Greenland Ice Core Project (NGRIP). The presented record reaches from the early Holocene back into the previous interglacial with a mean time resolution of about 75years. Between 11 and 120kyrBP, atmospheric N2O concentrations react substantially to the last glacial-interglacial transition (Termination 1) and millennial time scale climate variations of the last glacial period. For long-lasting Dansgaard/Oeschger (DO) events, the N2O increase precedes Greenland temperature change by several hundred years with an increase rate of about 0.8-1.3ppbv/century, which accelerates to about 3.8-10.7ppbv/century at the time of the rapid warming in Greenland. Within each bundle of DO events, the new record further reveals particularly low N2O concentrations at the approximate time of Heinrich events. This suggests that the response of marine and/or terrestrial N2O emissions on a global scale are different for stadials with and without Heinrich events. Key Points High-resolution record of atmospheric N2O from 11 to 120 kyr BPSubstantial N2O response to the last glacial-interglacial transition (T1)DO and Heinrich event cycles visible in the atmospheric N2O concentration ©2013. American Geophysical Union. All Rights Reserved.