Observations of tropospheric trace gases by ground-based high resolution FT-IR spectrometer

利用地面高分辨率傅立叶变换红外光谱仪观测对流层痕量气体

基本信息

批准号：
11680529
负责人：
TAKAHASHI Kenshi
金额：
$ 2.3万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

Tropospheric column amounts and mixing ratios of carbon monoxide (CO), ethane (C_2H_6), acetylene (C_2H_2), and hydrogen cyanide (HCN) were retrieved from ground-based infrared solar spectra. The spectra were recorded with high spectral resolution Fourier Transform Infrared (FTIR) spectrometers at Moshiri (44.4°N) and Rikubetsu (43.5°N) in northern.The retrievals show significant seasonal variations in the tropospheric content of the four molecules over northern Japan with maxima in winter-spring (February-April) for CO, C_2H_6 and C_2H_2 and in summer (May-July) for HCN.Simultaneous enhancements of the tropospheric concentration of the four molecules were occasionally observed during the observational period, possibly due to the same sources. Good correlations among the tropospheric amounts of CO, C_2H_6, and C_2H_2 indicated that they had similar sources and underwent similar processes of dilution. Trajectory calculations and global fire maps revealed that emissions of biomass burning on the Asian continent were transported eastward to northern Japan. Decreasing trends in tropospheric CO, C_2H_6, and C_2H_2 from May 1995 to June 2000 were found to be (-2.10±0.30), (-2.53±0.30), and (-3.99±0.57)%yr, respectively, while the trend of (-0.93±0.49)%/yr in HCN was not significant. Since stratospheric O_3 absorbs the solar UV radiation, the depletion of global stratospheric O_3 since mid-1980s resulted in an increase of the solar UV radiation on the earth surface. It is appear that the observed negative trends in tropospheric CO, C_2H_6, and C_2H_2 over northern Japan should be due to the increase in the solar UV radiation through the photochemical reactions with OH.In addition, reduced emissions of these gases from biomass burning and anthropogenic sources in the past decade would be another reason for the decreasing trends in troposphericCO, C_2H_6, and C_2H_2 observed in northern Japan from May 1995 to June 2000.

从地面红外太阳光谱中检索对流层一氧化碳（CO）、乙烷（C_2H_6）、乙炔（C_2H_2）和氰化氢（HCN）的柱体数量和混合比例，并用高光谱分辨率傅里叶变换红外光谱记录光谱。 (FTIR) 光谱仪位于 Moshiri (44.4°N) 和 Rikubetsu (43.5°N)反演结果显示，日本北部地区对流层四种分子含量存在显着的季节变化，CO、C_2H_6 和 C_2H_2 的最大值出现在冬春（2 月至 4 月），HCN 的最大值出现在夏季（5 月至 7 月）。在观测期间偶尔观察到这四种分子的对流层浓度，可能是由于对流层 CO 量之间具有良好的相关性。 C_2H_6和C_2H_2表明它们具有相似的来源并进行了相似的稀释过程。轨迹计算和全球火灾地图显示，亚洲大陆生物质燃烧的排放正在向东输送到日本北部，对流层CO、C_2H_6和C_2H_2呈减少趋势。 1995年5月至2000年6月的结果为（-2.10±0.30），分别为(-2.53±0.30)和(-3.99±0.57)%yr，而HCN的(-0.93±0.49)%/yr趋势不显着，因为平流层O_3吸收了太阳紫外线辐射，导致HCN的消耗。 20世纪80年代中期以来的全球平流层O_3导致地球表面太阳紫外线辐射增加，观察到的对流层呈负趋势。日本北部上空的CO、C_2H_6和C_2H_2应该是由于与OH发生光化学反应而导致太阳紫外线辐射增加。此外，过去十年生物质燃烧和人为源排放这些气体的减少也是造成这种现象的另一个原因。 1995年5月至2000年6月在日本北部观测到的对流层CO、C_2H_6和C_2H_2的减少趋势。