Spectroscopy and Spectral Analysis, Volume. 42, Issue 4, 1036(2022)
Observation of Variations of Ambient CO2 Using Portable FTIR Spectrometer
Measurement of CO2 concentration with high accuracy and precision is essential for monitoring local emission sources of greenhouse gases at regional and city scales. Based on Fourier transform spectroscopy and near-infrared solar absorption spectra collected by portable FTIR spectrometer, the column concentration of CO2 in the Hefei area from September 2016 to May 2020 was retrieved using the nonlinear least-squares algorithm. As the observation results show, the column concentration of CO2 has obvious seasonal variation, with the maximum value in spring, the fast decline in summer, and the minimum in autumn. The daily average value of XCO2 is between (401.23±0.60) and (418.41±0.31) ppm, while the monthly average value shows a seasonal amplitude of 6.96 ppm during 2017. XCO2 showed an increasing trend during the observation, with an annual growth rate of (2.71±0.66) ppm·yr-1. In order to verify the accuracy and reliability of portable FTIR spectrometer observations, we compared the observations with the high-resolution FTIR measurements. It is found that the mean deviation of XCO2 was about 1.32 ppm, the linear fitting coefficient was 1.08±0.03, and the correlation coefficient r was 0.97. Further, our data are compared with GOSAT satellite data, the average deviation of the two data is (0.63±1.76) ppm, and the correlation coefficient r is 0.86, showing a high correlation between ground-based data and satellite data. Also, ground-based observations in Shanghai were compared with the simultaneous observations in Hefei. The results showed that the variation of XCO2 in Shanghai is similar to our results. The daily average of XCO2 in Shanghai is between (411.87±1.07) and (416.63±1.70) ppm, and the value is between (415.09±0.84) and (417.80±0.67) ppm in Hefei in autumn. It is found that XCO2 in Hefei was slightly higher than that in Shanghai during the observation. The results provide the data for tracking carbon sources and sinks of greenhouse gases in the Hefei area.
Get Citation
Copy Citation Text
Ling-ling ZHA, Wei WANG, Yu XIE, Chang-gong SHAN, Xiang-yu ZENG, You-wen SUN, Hao YIN, Qi-hou HU. Observation of Variations of Ambient CO2 Using Portable FTIR Spectrometer[J]. Spectroscopy and Spectral Analysis, 2022, 42(4): 1036
Category: Research Articles
Received: Mar. 31, 2021
Accepted: --
Published Online: Jul. 25, 2023
The Author Email: ZHA Ling-ling (llzha96@163.com)