Japan Geoscience Union Meeting 2019

Presentation information

[J] Poster

A (Atmospheric and Hydrospheric Sciences ) » A-CC Cryospheric Sciences & Cold District Environment

[A-CC26] Ice cores and paleoenvironmental modeling

Tue. May 28, 2019 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall8, Makuhari Messe)

convener:Ryu Uemura(University of the Ryukyus), Kenji Kawamura(National Institute of Polar Research, Research Organization of Information and Systems), Ayako Abe-Ouchi(Atmosphere and Ocean Research Institute, The University of Tokyo), Nozomu Takeuchi(Chiba University)

[ACC26-P04] Methane concentration measurements of the Dome Fuji ice core using Continuous Flow Analysis system

Ikumi Oyabu1, Miho Arai1,4,5, *Kenji Kawamura1,2,3, Kyotaro Kitamura1, Jun Ogata1, Kumiko Goto-Azuma1,2 (1.National Institute of Polar Research, Research Organization of Information and Systems, 2.SOKENDAI (The Graduate University of Advanced Studies), 3.JAMSTEC, 4.Yamagata University, 5.Weathernews Inc.)

Keywords:Continuous Flow Analysis, Ice core, CH4, Dome Fuji

At the National Institute of Polar Research (NIPR), Continuous Flow Analyses (CFA) system has been developed. In addition to the measurements of melt water (e.g. water isotopes, micro-particles and major ions), the enclosed air is extracted from the water stream and measured for methane (CH4) concentration by a customized Cavity Ring-Down Spectrometer (CRDS) (Picarro G2301). The CFA system provides data at much higher resolution than classic discrete measurements, which can improve our knowledge and understanding of past climatic variations.

The CH4 concentration measured by CFA is affected by several factors, impacting precision, accuracy and resolution. The factors include dissolution of CH4 in meltwater and its imperfect extraction, sample mixing and smoothing in sample lines, and contamination by room air intrusion into the system at the interface between ice samples. The magnitudes of these effects have been investigated, and the data are corrected accordingly. Here, we report the results of various tests for assessing the performance of our CFA for CH4 measurement. Furthermore, the results of the measurement campaigns of the Dome Fuji ice core, covering the 8.2-kyr cooling event and a part of the last deglaciation, will also be presented.