共同研究報告書提出

共同研究報告書

研究区分	一般研究
研究課題	回転ラマン分光法を用いた氷床フィルンにおけるガス分別過程の解明
新規・継続の別	新規
研究代表者／所属	北見工業大学
研究代表者／職名	准教授
研究代表者／氏名	大野浩

研究目的	氷床フィルン中で生じていると考えられるガス分別現象を明らかにすることを目的とする.

研究内容・成果	Earlier gas measurements of firn air (atmosphere in open pore channels) at polar sites have revealed the occurrence of gas fractionation phenomena during bubble close-off， in addition to well-known thermal and gravitational gas separation. Nevertheless， because of difficulties posed by measurement， little is known about the distribution of air constituents in already closed pores (bubbles) in firn. Herein， we develop the application of high-sensitivity pure rotational Raman spectroscopy， combined with sample immersion in the fluorocarbon-based inert fluid for removing the optical disturbance by diffused reflection. That application efficiently elicits information about nitrogen and oxygen composition ratios (N2/O2 or O2/N2) for each air bubble in firn. The developed methodology presents important implications for elucidating how gas records are formed and modified in the course of pore close-off in polar firn.

成果となる論文・学会発表等	Hiroshi Ohno， Yoshinori Iizuka， et al. Pure rotational Raman spectroscopy applied to N2/O2 analysis of air bubbles in polar firn， Journal of Glaciology， under review.