Variations of the carbon isotopic ratio in atmospheric CO_2 over the last 250 years recorded in an ice core from H15,Antarctica

元データ 国立極地研究所

概要

Variations of δ^<13>C in atmospheric CO_2 were reconstructed for the period of 1724 to 1961 by analyzing a high-accumulation ice core drilled at H15,Antarctica. Measured values of δ^<13>C were corrected for the gravitational enrichment which occurred in the firn, on the basis of the analytical results of δ^<15>N in N_2 in the core. From the vertical profile of δ^<15>N calculated using a diffusion model for the firn, it was suggested that the air in the layer shallower than 17m depth was mixed well with the atmosphere over the firn surface. The average value of δ^<13>C during the period 1724-1775 was found to be -6.67±0.11‰. δ^<13>C decreased secularly from this value to -7.33‰ in 1961,and its trend was enhanced especially after the late 19th century, corresponding to the long-term increase of the CO_2 concentration. CO_2 fluxes estimated by deconvolution analysis of the reconstructed CO_2 concentrations with the box-diffusion model accounted for the observed variations of δ^<13>C fairly well. It was also suggested that a dip of δ^<13>C found at the end of the 18th century was attributable to terrestrial biospheric CO_2 emissions enhanced under high air temperatures.

著者

Watanabe Okitsugu National Institute of Polar Research, Research Organization of Information and Systems
Fujii Yoshiyuki National Institute of Polar Research, Research Organization of Information and Systems
Kawada Kunio Center For Atmospheric And Oceanic Studies Graduate School Of Science Tohoku University
張 紀久夫 阪大基:福井工大工
Kawamura Kenji Center For Atmospheric And Oceanic Studies Graduate School Of Science Tohoku University
Watanabe O National Institute Of Polar Research Research Organization Of Information And Systems
Watanabe Okitsugu National Institute Of Polar Research
Kamiyama K National Institute Of Polar Research Research Organization Of Information And Systems
Morimoto S National Institute Of Polar Research Organization Of Information And Systems
Nakazawa Takakiyo Center for Atmospheric and Oceanic Studies, Tohoku University
Aoki Shuhji Center for Atmospheric and Oceanic Studies, Graduate School of Science, Tohoku University
Morimoto Shinji National Institute of Polar Research
Nakazawa Takakiyo Center For Atmospheric And Oceanic Studies Graduate School Of Science Tohoku University
AOKI Shuhji National Institute of Polar Research
Aoki Shuhji Center For Atmospheric And Oceanic Studies Faculty Of Science Tohoku University
Morimoto S National Inst. Polar Res. Tokyo Jpn
Kawamura K Center For Atmospheric And Oceanic Studies Tohoku University
Kawada K Toyama Univ. Toyama
清水 明 東大教養
Aoki Shuji Center For Atmospheric And Oceanic Studies Graduate School Of Sci. Tohoku Univ.
Aoki Shuhji Faculty Of Science Tohoku University
清水 明 東大院総合文化・科技団
Ishizawa Misa Frontier Research System for Global Change
Fujii Yoshiyuki National Institute Of Polar Research
Watanabe Okitsusgu National Institute of Polar Research
Mae S National Institute Of Polar Research Research Organization Of Information And Systems
Kawada Kunio Department Earth Science Toyama University
Machida Toshinobu National Institute for Environmental Studies
Mae Shinji Department Of Applied Physics Hokkaido University
Nakazawa Takakiyo Center For Atmospheric And Oceanic Studies Graduate School Of Sci. Tohoku Univ.
Ishizawa Misa Frontier Research System For Global Change Institute For Global Change Research
Nakazawa Takakiyo Center For Atmospheric And Oceanic Studies Faculty Of Science
Murayama Syohei National Institute For Resources And Environment
清水 明 Center For Atmospheric And Oceanic Studies Graduate School Of Science Tohoku University
Nakazawa T Center For Atmospheric And Oceanic Studies Faculty Of Science
Mae Shinji National Institute For Resources And Environment
Morimoto Shinji National Institute For Resources And Environment
SHIMIZU Akira Deparment of Physics, Rikkyo University

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