A study of atmospheric budget of methyl chloride

氯甲烷大气收支的研究

• 批准号: 18340179
• 负责人: YOKOUCHI Yoko
• 金额: $ 9.6万
• 依托单位: National Institute for Environmental Studies
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2006
• 资助国家: 日本
• 起止时间: 2006 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18340179/
• 关键词: methyl chloride; tropical plants; budget; emission; stable isotope

Stable carbon isotope ratios of methyl chloride (CH_3C1) emitted from tropical plants were measured using growing in a glasshouse. Using the isotope signatures to an isotopic mass balance calculation, global CH_3C1 emission by tropical plants was estimated to be approximately 1500-3000 Gg yr^<-1>. At a tropical rain forest in Peninsular Malaysia, we conducted a survey of CH_3C1 emitting plants for the 117 species of tropical plants, and 23 species were identified as CH3C1-emitting plants with the mean flux of 5 μg m^<-2> h^<-1>. The estimated fluxes were consistent with the canopy scale fluxes (5〜66μg m^<-2> h^<-1>) measured by the micrometeorological. gradient method at the forest. Emission of CH_3C1 from a subtropical island (Iriomote Island) was estimated to be 2〜26 μg m^<-2> h^<-1> using the enhanced CH_3C1 concentration at downwind sites.To determine δ^<13>C of CH_3C1 in seawater, we developed an analytical system enabling both extraction of CH_3C1 in seawater on board a research vessel together with NMHCs, and storage within a glass ampoule under CO_2 matrix for several months without changing their δ^<13>C, allowing determination of the δ^<13>C values by using CF-IR MS at a shore-based laboratory. By using the analytical system, we can determine δ^<13>C at precisions<2‰ for CH_3C1 and<1‰ for NMHCs dissolved in 2.2 L seawater. The δ_<13>C determination in coastal seawater reveal distinct differences in the range of variation in the δ^<13>C between alkanes, alkenes, and CH_3C1. While the alkenes exhibited almost uniform δ^<13>C from-26 to-27‰VPDB, both alkanes (-27 to-35‰VPDB) and CH_3C1 (-49±16±VPDB) exhibited more C^<13>-depleted values with greater variations. The δ^<13>C can be a useful tool to study the mechanisms and/or the pathways of their production in seawater.

采用温室生长法测定了热带植物排放的氯甲烷（CH_3C_1）的稳定碳同位素比值。利用同位素质量平衡计算的结果，估算了全球热带植物CH_3C_1排放量约为1500-3000 Gg/yr<-1>。在马来西亚半岛的热带雨林中，对117种热带植物进行了CH_3C_1排放的调查，确定了23种植物为CH_3C_1排放植物，平均排放通量为5 μg·m ~<-2>（-1）·h ~（-1）<-1>。估算的通量与微气象观测的冠层尺度通量（5 × 66μg m^<-2>h^<-1>）基本一致。森林中的梯度法为了<-2><-1>测定海水中CH_3C_1的δ^<13>C，我们开发了一种分析系统，该系统既能在考察船上提取海水中的CH_3C_1和NMHCs，又能在CO_2基质下储存几个月而不改变它们的δ^<13>C，允许<13>在岸基实验室中使用CF-IR MS测定δ^ C值。用该分析系统测定<13>2.2L海水中CH_3Cl和NMHCs的δ^ C，其精度分别为&lt;2‰和&lt;1‰。近岸海水δ ^<13>C测定结果表明，烷烃、烯烃和CH_3C_1的δ^ C变化范围存在明显差异<13>。烯烃的δ^ C值<13>在-26至-27 ‰VPDB之间，而烷烃（-27至-35 ‰VPDB）和CH_3Cl（-49 16 ±VPDB）的δ^<13>C值更低，变化更大。δ^<13>C可作为研究海水中δ ^C产生机制和/或途径的有用工具。

项目成果

Stable carbon isotope ratio of methyl chloride emitted from glasshouse-grown tropical plants and its implication for the global methyl chloride budget

温室种植的热带植物排放的氯甲烷的稳定碳同位素比及其对全球氯甲烷预算的影响

• 发表时间: 2008
• 期刊: Geophys.Res.Lett. 35
• 作者: K. Takaki;K. Imanishi;T. Murakami;S. Mukaigawa;T. Fujiwara;Y. Suda;T.Saito&Y.Yokouchi
• 通讯作者: T.Saito&Y.Yokouchi

溶存非メタン炭化水素炭素安定同位体比分析手法の開発

溶解非甲烷烃碳稳定同位素比分析方法的开发

• 发表时间: 2006
• 作者: 古用啓介;ほか
• 通讯作者: ほか

亜熱帯海域にける生物起源ガスの分布と同位体組成

亚热带海域生物气分布及同位素组成

• 发表时间: 2007
• 作者: 角皆潤;ほか
• 通讯作者: ほか

波照間島における海洋起源VOCの大気観測

波照间岛海洋 VOC 的大气观测

• 发表时间: 2007
• 作者: 横内陽子;ほか
• 通讯作者: ほか

Diurnal variation in methyl halide emission rates from tropical ferns

热带蕨类植物卤代甲烷排放率的日变化

• 发表时间: 2006
• 期刊: Atmospheric Environment 40
• 作者: K. Imanishi;S. Mukaigawa;K. Takaki;T. Fujiwara;K. Yukimura;Y. Suda;T.Saito
• 通讯作者: T.Saito