Development of a Laser Gas Analyzer for Fast CO<sub>2</sub> and H<sub>2</sub>O Flux Measurements Utilizing Derivative Absorption Spectroscopy at a 100 Hz Data Rate
Mingxing Li,
Ruifeng Kan,
Yabai He,
Jianguo Liu,
Zhenyu Xu,
Bing Chen,
Lu Yao,
Jun Ruan,
Huihui Xia,
Hao Deng,
Xueli Fan,
Bangyi Tao,
Xueling Cheng
Affiliations
Mingxing Li
AnHui Institute of Optics and Fine Mechanics, HeFei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China
Ruifeng Kan
AnHui Institute of Optics and Fine Mechanics, HeFei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China
Yabai He
AnHui Institute of Optics and Fine Mechanics, HeFei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China
Jianguo Liu
AnHui Institute of Optics and Fine Mechanics, HeFei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China
Zhenyu Xu
AnHui Institute of Optics and Fine Mechanics, HeFei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China
Bing Chen
AnHui Institute of Optics and Fine Mechanics, HeFei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China
Lu Yao
AnHui Institute of Optics and Fine Mechanics, HeFei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China
Jun Ruan
AnHui Institute of Optics and Fine Mechanics, HeFei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China
Huihui Xia
AnHui Institute of Optics and Fine Mechanics, HeFei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China
Hao Deng
AnHui Institute of Optics and Fine Mechanics, HeFei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China
Xueli Fan
AnHui Institute of Optics and Fine Mechanics, HeFei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China
Bangyi Tao
State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China
Xueling Cheng
State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
We report the development of a laser gas analyzer that measures gas concentrations at a data rate of 100 Hz. This fast data rate helps eddy covariance calculations for gas fluxes in turbulent high wind speed environments. The laser gas analyzer is based on derivative laser absorption spectroscopy and set for measurements of water vapor (H2O, at wavelength ~1392 nm) and carbon dioxide (CO2, at ~2004 nm). This instrument, in combination with an ultrasonic anemometer, has been tested experimentally in both marine and terrestrial environments. First, we compared the accuracy of results between the laser gas analyzer and a high-quality commercial instrument with a max data rate of 20 Hz. We then analyzed and compared the correlation of H2O flux results at data rates of 100 Hz and 20 Hz in both high and low wind speeds to verify the contribution of high frequency components. The measurement results show that the contribution of 100 Hz data rate to flux calculations is about 11% compared to that measured with 20 Hz data rate, in an environment with wind speed of ~10 m/s. Therefore, it shows that the laser gas analyzer with high detection frequency is more suitable for measurements in high wind speed environments.
