| The long-term evolutions and the regional characteristics of atmospheric methane concentrations in Nagoya, 1983-1997. | |
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MedLine Citation:
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PMID: 11194161 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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This study provides information on the long-term evolutions of the atmospheric methane (CH4) concentrations in Nagoya City, Japan, which were analyzed by using the continuous monitoring data observed at the eight observatory stations for 1983-1997. The 15-year records of the atmospheric CH4 concentrations were examined by means of a time-series analysis using a fast Fourier transform with a low-pass filter to elucidate the seasonal cycles and the long-term trends. The annual averages of the CH4 concentrations in Nagoya were 1.85 ppmv (parts per million by volume), 1.91 ppmv, and 1.90 ppmv in 1988, 1995 and 1997, respectively. Moreover, the annual average growth rate showed a drastic decrease from 17 ppbv (parts per billion by volume) year(-1) in 1992 to 2 ppbv year(-1) in 1993, and further down to 7 ppbv year(-1) in 1997. Comparison of the atmospheric CH4 records in Nagoya with those in global air of the northern hemisphere observed at Mauna Loa observatory in Hawaii, USA, allows us to estimate the excess concentration of CH4 in the urban atmosphere of Nagoya, which was 0.17 ppmv in 1988 and 0.15 ppmv in 1997. On a local scale, the atmospheric CH4 concentrations in the northern part of Nagoya City increased until 1992 and then gradually decreased from 1993 to 1997, although those in the south-western urban areas constantly increased at the averaged growth rate of 13 ppbv year(-1) for 1988-1997. The variation of the long-term trends of the CH4 concentrations in Nagoya may be ascribed to the emission changes from the CH4 sources due to the human activities such as waste dumping and landfills. |
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Authors:
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A Ito; I Takahashi; Y Nagata; K Chiba; H Haraguchi |
Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: The Science of the total environment Volume: 263 ISSN: 0048-9697 ISO Abbreviation: Sci. Total Environ. Publication Date: 2000 Dec |
Date Detail:
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Created Date: 2001-01-17 Completed Date: 2001-02-15 Revised Date: 2004-11-17 |
Medline Journal Info:
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Nlm Unique ID: 0330500 Medline TA: Sci Total Environ Country: Netherlands |
Other Details:
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Languages: eng Pagination: 37-45 Citation Subset: IM |
Affiliation:
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Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Japan. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Air Pollution
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analysis* Environmental Monitoring Humans Japan Methane / analysis* Refuse Disposal Urban Population |
| Chemical | |
Reg. No./Substance:
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74-82-8/Methane |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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