Development of Fast Response Carbon Dioxide and Humidity Instrument

快速响应二氧化碳、湿度仪器的研制

基本信息

批准号：
60840009
负责人：
OHTAKI Eiji
金额：
$ 2.94万
依托单位：
College of Liberal Arts and Sciences, Okayama University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research
财政年份：
1985
资助国家：
日本
起止时间：
1985 至 1986
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-60840009/
关键词：
Carbon dioxide flux Humidity flux 渦相関法炭酸ガス水蒸気変動計

项目摘要

The accurate measurement of turbulent transport of carbon dioxide in the atmospheric surface layer has been expected to achieve deep understanding of the carbon dioxide - climate ploblem. The eddy correlation technique is the most promising one to measure turbulent transport of carbon dioxide. In order to investigate carbon dioxide transport by the eddy correlation technique, we developed the fast response instrument designed to measure simultaneous fluctuations of carbon dioxide and humidity. The measuring frequency is 30 Hz and the sensing path length is 20 cm. The noise is 0.3 ppm for carbon dioxide measurement and 0.01 g/kg for humidity measurement. The drift of the instrument is about 0.16 ppm/h and 0.01 g kg/h, respectively.The instrument is applied to the field experiments under various surface conditions: stubble field, sea surface and vegetated fields. The wc-cospectra of vertical wind velocity and carbon dioxide fluctuations are calculated by Tukey's scheme in order to investigate the carbon dioxide transport processes. It is noted that the we-cospectra from the stubble field are confined to a narrow range of 0.02 to 0.1 Hz. The average values of turbulent transport of carbon dioxide are about -0.05 mg <m^(-2)s^(-1)> in the daytime and less than 0.05 mg <m^(-2)s^(-1)> in the nighttime. The raw values of turbulent transport of carbon dioxide over sea surface are negative of -0.05 to -0.17 mg <m^(-2)s^(-1)> .Field experiments show that the present instrument is promising for flux measurements of carbon dioxide and humidity by the eddy correlation technique in conjunction with a sonic anemometer.

预计，二氧化碳在大气表面层中的湍流运输的准确测量可以深入了解二氧化碳 - 气候综合。涡流相关技术是测量二氧化碳湍流转运的最有希望的技术。为了通过涡流相关技术研究二氧化碳的转运，我们开发了旨在测量二氧化碳和湿度同时波动的快速响应仪器。测量频率为30 Hz，感应路径长度为20 cm。二氧化碳测量值的噪声为0.3 ppm，湿度测量为0.01 g/kg。该仪器的漂移分别为0.16 ppm/h和0.01 g kg/h。在各种表面条件下，仪器应用于田间实验：茬，海面和植被场。垂直风速度和二氧化碳波动的WC-Cosectra由Tukey的方案计算，以研究二氧化碳运输过程。据注意，从残茬场的We-Cosectra局限于0.02至0.1 Hz的狭窄范围。二氧化碳的湍流传输的平均值约为-0.05 mg <m^（-2）s^（ - 1）>在夜间，在夜间，小于0.05 mg <m^（ - 2）s^（ - 1）>。二氧化碳在海面上的湍流转运的原始值为-0.05至-0.17 mg <m^（-2）s^（ - 1）>。场实验表明，目前的仪器有望通过与SonicAnemoter结合使用EDDY校正技术来测量二氧化碳和湿度的通量测量。