Methane in NEEM-2011-S1 ice core from North Greenland, 1800 years continuous record: outliers removed, v2 ...

• Main Authors: Rhodes, Rachael H, Brook, Edward J
• Format: Dataset
• Language: English
• Published: PANGAEA 2019
• Subjects: atmospheric composition; biogeochemical cycles; Greenland; Holocene; Ice core; Methane; DEPTH, ice/snow; Age; AGE; Ice drill; Age, calculated from a AD; see abstract; North Greenland Eemian Ice Drilling NEEM; ice core; North Greenland
• Online Access: https://dx.doi.org/10.1594/pangaea.899037; https://doi.pangaea.de/10.1594/PANGAEA.899037

Description and NotesDescription: Methane concentration from the Greenland NEEM-2011-S1 Ice Core from 71 to 408m depth (~270-1961 CE). Methane concentrations analysed online by laser spectrometer (SARA, Spectroscopy by Amplified Resonant Absorption, developed at Laboratoire Interdisciplinaire de Physique, Grenoble, France) on gas extracted from an ice core processed using a continuous melter system (Desert Research Institute). Methane data have a 5 second integration time (raw data acquisition rate 0.6 Hz). Analytical precision, from Allan Variance test, is 0.9 ppb (2 sigma). Long-term reproducibility is 2.6% (2 sigma). Gaps in the record are due to problems during online analysis. Online analysis conducted August-September 2011.Note: Lat-Long provided is for main NEEM borehole. The NEEM-2011-S1 core was drilled 200 m distance away in 2011 to 410 m depth.Methane concentrations are reported on NOAA2004 scale (instrument calibrated on dry synthetic air standards).A correction factor of 1.079 has been applied ... : NEEM-2011-S1 CH4 no outliers.Data minus data points exceeding cut-off value. Cut-off value is 2*median absolute deviation (MAD)> 15 yr running median. Different MAD values used for 250-1000 AD and 1100-1835 AD sections of record. ...