Observational Research of Stratospheric Hydroxyle

平流层羟基的观测研究

• 批准号: 02640324
• 负责人: IWAGAMI Naomoto
• 金额: $ 1.28万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02640324/
• 关键词: Hydroxyle; Stratosphere; UV-spectroscopy

Hydroxide is one of the most important minor constituents in the middle atmosphere because of its high reactivity; however, only a few measurements have been reported so far because of its extremely small abundance. In this research, we succeeded to quantify the stratospheric hydroxyle column by UV spectroscopy to measure A^2SIGMA-X^2II (0,0) band 1P_1, and 3Q_1, absorption lines at 308 nm using the sun as a light source.The measuring system consists of a 1.5 m double-pass grating monochromator, a linear image sensor with a one-stage MCP, a sun-tracker and a 0.5 m telescope, and is set in Hongo campus of the University of Tokyo located at the central Tokyo City. The spectral purity of the system used is 1.2 pm which is a little larger than the Doppler width of the hydroxyle lines. Difficulty comes from the fact that the solar spectrum in this region is filled with solar absorption lines which are much stronger than the terrestrial hydroxyle absorption features. In this research we util … More ized the Doppler shift of the solar spectrum due to the solar rotation in discriminating the terrestrial absorptions from the solar features; this is the most distinctive point of this research. By comparing the solar spectra measured on the east and west edges of the solar disk, it is possible to cancel out the solar structure and make the terrestrial absorption much more prominent.Good data have been obtained since May 1992 after various troubles such as inaccurate sun tracking, insufficient ability of the cooling system, degradation of the optics and temperature drift of the mechanics. The measured hydroxyle vertical columns at noon in summer and winter are 6 x 10^<13> cm^<-2> and 4 x 10^<13> cm^<-2>, respectively, and decreases to 4 x 10^<13> cm^<-2> in the summer evening when the solar zenith angle reaches 60ﾟ. This behavior can roughly be reproduced with a one- dimensional chemical-diffusive model; our understanding of the middle atmosphere photo-chemistry is found to be not far from the truth. Less

氢氧化物是中层大气中最重要的次要成分之一，因为它的反应性很高;然而，由于其丰度极低，迄今为止只有少数测量报告。本研究以太阳为光源，利用紫外光谱技术对平流层羟基柱进行了定量测量，测量系统由1.5 m双通光栅单色仪、带单级MCP的线阵图像传感器、太阳跟踪仪和0.5 m望远镜组成，位于东京市中心的东京大学本乡校区。所用系统的光谱纯度为1.2 μ m，比羟线的多普勒宽度稍大。困难在于这一地区的太阳光谱充满了比地球羟基吸收特征强得多的太阳吸收线。在这项研究中，我们利用 ...更多信息 利用太阳自转引起的太阳光谱的多普勒频移来区分太阳特征和地球反射，这是本研究最有特色的地方。通过比较太阳盘面东西边缘的光谱，可以消除太阳结构，突出地球吸收，克服了跟踪不准、冷却系统能力不足、光学系统退化、机械装置温漂等问题，自1992年5月以来，获得了较好的数据。在夏季和冬季的中午，测得的羟垂直柱分别为6 × 10^<13>cm^<-2>和4 × 10^<13>cm^<-2>，<13><-2>在夏季的晚上，当太阳天顶角达到60 °时，羟垂直柱减小到4 × 10^ cm^。这种行为可以用一个一维的化学扩散模型粗略地再现，我们对中层大气光化学的理解与事实相差不远。少