(1) N2O and CH4 record from the NorthGRIP ice core (Greenland) covering Dansgaard-Oeschger Events 9 to 12.
Measurements were performed along the North Greenland Ice Core Project (NGRIP) ice core (75 deg 06' N, 42 deg 20' W) at 158 and 164 different depth levels for N2O and CH4, respectively. These data cover the time period of D-O events 9 to 12. The ... resolution of the NGRIP records is about 63 years with highest resolutions of up to 35 years at the beginning of D-O events.
(2) N2O and CH4 records from the GRIP ice core (Greenland) covering Dansgaard-Oeschger Events 19 and 20.
Measurements were performed along the Greenland Ice Core Project (GRIP) ice core (72 deg 34'N, 37 deg 37'W). Ninety-six and 107 samples from different depth levels were measured for N2O and CH4, respectively, covering the time period of D-O events 19 and 20. The GRIP record achieves a mean time resolution of 97 years and 77 years for N2O and CH4, respectively, reaching a resolution of about 30 years at the beginning of D-O event 19.
ABSTRACT (from the online documentation): Greenhouse gas measurements along polar ice cores provide important insight into the former composition of the atmosphere, its natural variations, and the responses to fast climatic changes in the past. We present high-resolution nitrous oxide (N2O) and methane (CH4) records measured along two ice cores from central Greenland covering part of Marine Isotope Stages 3 and 4 in the last glacial epoch. The N2O data confirm the hypothesis that N2O shows variations in phase to fast climatic changes observed in the Northern Hemisphere, the so-called Dansgaard-Oeschger (D-O) events. Variations exist not only for events with a long duration (1500 years and more) but also for the shorter ones. The comparison with CH4 unveils interesting differences between the response of CH4 and N2O to D-O events. While the average amplitudes of CH4 oscillations associated with D-O events are similar to those of the Northern Hemisphere summer insolation, the magnitude of the N2O concentration change instead correlates with the duration of the D-O events. The records give further insight into the timing of concentration changes at the beginning of D-O events. They show that for long-lasting events the N2O concentration starts to increase before both the sharp increase in the CH4 concentration and the temperature reconstructed for Greenland.
The Niels Bohr Institute
Department of Geophysics
University of Copenhagen
Juliane Maries Vej 30
Province or State:
Fluckiger, J., T. Blunier, B. Stauffer, J. Chappellaz, R. Spahni, K. Kawamura, J. Schwander, T.F. Stocker, and D. Dahl-Jensen, N2O and CH4 variations during the last glacial epoch: Insight into global processes, Glob. Biogeochem. Cycles, Vol. 18, GB1020, doi:10-1029/2003GB002122.