West Antarctic Ice Sheet (WAIS) Divide ice core ultra-high resolution continuous CH4 measurements 67.2-9.8 ka BP ...

• Main Authors: Rhodes, Rachael H, Brook, Edward J, Blunier, Thomas, McConnell, Joseph R, Romanini, Daniele
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2017
• Subjects: Antarc*; Antarctic; Greenland; Hudson Strait; ice core; Ice Sheet; Iceberg*; North Atlantic
• Online Access: https://dx.doi.org/10.1594/pangaea.875982; https://doi.pangaea.de/10.1594/PANGAEA.875982

Rhodes et al. 2015 (doi:10.1126/science.1262005)The causal mechanisms responsible for the abrupt climate changes of the Last Glacial Period remain unclear. One major difficulty is dating ice rafted debris (IRD) deposits associated with Heinrich events: Extensive icebergs influxes into the North Atlantic Ocean, linked to global impacts on climate and biogeochemistry. In a new ice core record of atmospheric methane with ultra-high 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.---Rhodes et al. 2017 (doi:10.1002/2016GB005570)In order to understand atmospheric methane (CH_4) ... : For more information please contact Prof. Edward Brook, Oregon State University (mailto:[e-mail])In the majority of cases the 2-yearly spline fit will be the most suitable for your application. -- 2 yearly cubic smoothing spline of CH_4 data from the WAIS Divide ice core: 2 yearly cubic smoothing spline fit to the "Experiment-time-integrated CH4 data from all 3 instruments" (Dataset doi:10.1594/PANGAEA.875980). The 2 yearly cubic smoothing spline fills gaps in the data set and reduces data set size, whilst also reducing noise (that could be noise linked to the wider analytical system e.g., pressure fluctuations, or archival noise that does not reflect the paleo-atmosphere).-- Experiment-time integrated data: Data integrated to the optimal integration time (n.b. where time refers to experiment time, not age of gas sample). No further smoothing or resampling algorithm has been applied. The optimal integration time was selected by performing an Allan variance test on measurements of a ...