Global cycles of greenhouse gases during the last 100 years implied by firn air data

2009 Fiscal Year Final Research Report

• Project/Area Number: 19540454
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Meteorology/Physical oceanography/Hydrology
• Research Institution: Miyagi University of Education
• Principal Investigator: SUGAWARA Satoshi Miyagi University of Education, 教育学部, 准教授 (80282151)
• Co-Investigator(Renkei-kenkyūsha): AOKI Shuji 東北大学, 大学院・理学研究科, 教授 (00183129) ; KAWAMURA Kenji 国立極地研究所, 研究教育系, 助教 (90431478)
• Project Period (FY): 2007 – 2009
• Keywords: 陸域水循環 / 物質循環

Research Abstract

Air samples were collected from different depths of the firn layer at YM85, Antarctica, and NGRIP, Greenland, respectively, and analyzed for CO_2, and CH_4, concentrations and their isotopic ratios. The CO_2, and CH_4 concentrations at 70m depth at YM85 are 304ppm and 970ppb, respectively. Their effective age was estimated to be about 90 years by using a one-dimensional numerical model. The vertical distribution of CH_4 concentration in the firn layer can be reconstructed by a linear combination of the age distribution functions weighted by the atmospheric CH_4 concentrations in the past.Therefore, the most plausible past atmospheric record of CH_4 can be derived iteratively so that its observed profile in the firn layer was reproduced well. Same method was also applied to the reconstructions of carbon and hydrogen isotopic ratios. Temporal variations of atmospheric CH_4 budget was calculated from the atmospheric histories of concentration and its carbon and hydrogen isotopic ratios. This result shows that the CH_4 emission from biomass burning would be important during last 100 years.

Research Products

• [Journal Article] Temporal and spatial variations of carbon monoxide in the western part of the Pacific Ocean (2009)
  • Author(s): Yashiro, H., Sugawara, S., Sudo, K., Aoki S., Nakazawa, T.
  • Journal Title: J.Geophys.Res. 114 Pages: D08305
  • Peer Reviewed
• [Journal Article] Age of stratospheric air unchanged within uncertainties over the past 30 years (2009)
  • Author(s): Engel, A., Mobius, T., Bonisch, H., Schmidt, U., Heinz, R., Levin, I., Atlas, E., Aoki, S., Nakazawa, T., Sugawara, S., Moore, F., Hurst, D., Elkins, J., Schauffler, S., Andrews, A., Boering, K.
  • Journal Title: Nature Geosci. 2
  • Peer Reviewed
• [Journal Article] Gravitational separation detected from O_2/N_2, δ^<15>N of N_2, δ^<18>O of O_2, Ar/N_2 observed in the lowermost part of the stratosphere at northern middle and high latitudes in early spring of 2002 (2008)
  • Author(s): Ishidoya, S., Morimoto, S., Sugawara, S., Watai, T., Machida, T., Aoki, S., Nakazawa, T., Yamanouchi, T.
  • Journal Title: Geophys.Res.Lett. 35 Pages: L03812
  • Peer Reviewed
• [Journal Article] Gravitational separation of major atmospheric components of nitrogen and oxygen in the stratosphere (2008)
  • Author(s): Ishidoya, S., Sugawara, S., Morimoto, S., Aoki, S., Nakazawa, T.
  • Journal Title: Geophys.Res.Lett. 35 Pages: L03811
  • Peer Reviewed
• [Journal Article] Temporal and spatial variations of the atmospheric CO_2 concentration in China (2008)
  • Author(s): Zhang, D., Tang, J., Shi, G., Wen, M., Nakazawa, T., Aoki, S., Sugawara, S., Morimoto, S., Patra, P. K., Hayasaka, T., Saeki, T.
  • Journal Title: Geophys.Res.Lett. 35 Pages: L03801
  • Peer Reviewed
• [Journal Article] Temporal variations of atmospheric carbon dioxide in the southernmost part of Japan (2007)
  • Author(s): Zhang, X., Nakazawa, T., Ishizawa, M., Aoki, S., Nakaoka, S., Sugawara, S., Maksyutov, S., Saeki, T., Hayasaka, T.
  • Journal Title: Tellus 59B Pages: 654-663
  • Peer Reviewed
• [Journal Article] Temporal variations of the atmospheric nitrous oxide concentration and its δ^<15>N and δ^<18>O for the latter half of the 20th century reconstructed from firn air analyses (2007)
  • Author(s): Ishijima, K., Sugawara, S., Kawamura, K., Hashida, G., Morimoto, S., Murayama, S., Aoki, S., Nakazawa, T.
  • Journal Title: J.Geophys.Res. 112 Pages: D03305
  • Peer Reviewed
• [Presentation] Long-term variation of the carbon isotopic ratio of stratospheric CO_2 (2009)
  • Author(s): Sugawara, S., S. Aoki, T. Nakazawa, K. Genma, S. Ishidoya, S. Morimoto
  • Organizer: 8th International Carbon Dioxide Conference
  • Place of Presentation: Germany
  • Year and Date: 20090913-20090919
• [Presentation] Possible gravitational separation effect on the mean age of stratospheric air in the Arctic polar vortex (2008)
  • Author(s): Sugawara, S., S. Ishidoya, S. Aoki, T. Nakazawa
  • Organizer: International Global Atmospheric Chemistry 2008
  • Place of Presentation: Annecy
  • Year and Date: 20080907-20080912
• [Remarks] ホームページ等