Study on atmospheric chemical mechanisms related to each hemispherical atmospheric OH trend derived from AGAGE observation
| Project/Area Number |
14580558
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Environmental dynamic analysis
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| Research Institution | National Institute of Advanced Industrial Science and Technology (AIST) |
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Principal Investigator |
KUTSUNA Shuzo National Institute of Advanced Industrial Science and Technology (AIST), Research Institute for Environmental Management Technology, Potential Pollutants Group, Senior Research Scientist, 環境管理技術研究部門・未規制物質研究グループ, 主任研究員 (60344131)
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| Co-Investigator(Kenkyū-buntansha) |
HIROKAWA Jun Hokkaido University, Graduate School of Environmental Earth Science, Division of Material Science, Associated Professor, 大学院・地球環境科学研究科・物質環境科学専攻, 助教授 (20262115)
TAKAMI Akinori National Institute for Environmental Studies, Atmospheric Environment Division, Atmospheric Chemical Reaction Section, Senior Research Scientist, 大気圏環境研究領域・大気反応研究室, 主任研究員 (00262030)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2003: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 2002: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | AGAGE / methyl chloroform / atmospheric OH concentration / heterogeneous reaction / clay minerals / Impinging flow method / chemical ionization mass spectrometer / Falling film absorber / OHラジカル / 不均一過程 / エーロゾル / HO_2ラジカル / ハロゲン種 |
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| Research Abstract |
When the atmospheric OH concentration is inferred from long-term ground-based observatory data on atmospheric concentration of CH_3CCl_3 in the AGAGE, a gas-phase reaction with OH is considered a main atmospheric sink of CH_3CCl_3,and photolysis and dissolution into sea water are regarded as minor sinks of CH_3CCl_3. In this study, an additional sink of CH_3CCl_3, that is, heterogeneous decomposition on clay minerals, was examined. The reaction of CH_3CCl_3 on 25 standard day minerals was examined with a closed-circulation reactor and found that the decomposition of CH_3CCl_3 proceeded through CH_3CCl_3→CH_2=CCl_2+HCl at 313 K for most of the clay minerals examined (γ〜10-9).
The uptake coefficients (γ) of NO_2 and SO_2 to the aqueous surface were measured using the impinging flow apparatus. The aqueous solution including H_2O_2 or C_6H_4(OH)_2 gave larger γ values of NO_2 than pure water, because aqueous phase reaction of NO_2 with the solutes increased the γ value. We cannot observe any increase in the γ values of NO_2 or SO_2 when quasi-seawater was examined, influence of aqueous phase chemical reaction on the γ value of OH radicals was estimated.
The influence of water vapor on determination of Br_2 with a chemical ionization mass spectrometer was studied. Since a reagent associated with water to form hydrated ions, the mass peak of Br_2 ion could not be normalized with the peak of the reagent ion. However, we have indicated that it can be normalized with the peaks of both the reagent and the hydrated ions. A falling film absorber was prepared to measure the uptake coefficients (γ) to liquid surfaces and it was applied to measurement of γ of Br_2 to the water surface. Comparison of the measurement with the simulated calculation revealed that the aqueous phase reaction was a limiting-step in the uptake of Br_2 to water.
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Report
(3 results)
Research Products
(4 results)
