Prof. Rajan K S and Mahesh Pathakoti, a Ph.D student working with Prof. Rajan published a paper on Ground-Based Remote Sensing of Total Columnar CO2, CH4, and CO Using EM27/SUN FTIR Spectrometer at a Suburban Location (Shadnagar) in India and Validation of Sentinel-5P/TROPOMI in IEEE Geoscience and Remote Sensing Letters.

The other authors of this paper are Vijay Kumar Sagar, Mahalakshmi D V,  Sesha Sai M V R from Earth and Climate Sciences Area, National Remote Sensing Centre, Indian Space Research Organization (ISRO), Hyderabad; Frank Hase and Darko Dubravica from Karlsruhe Institute of Technology (KIT), Institute for Meteorology and Climate Research (IMK-ASF), Karlsruhe, Germany and Mahesh Kumar Sha from Royal Belgian Institute for Space Aeronomy (BIRA-IASB), Brussels, Belgium.

Research work as explained by the authors: Greenhouse gases (GHGs) play an important role in controlling local air pollution as well as climate change. In this study, we retrieved column-averaged dry-air (X) mole fractions of carbon dioxide (CO2), methane (CH4), and carbon monoxide (CO) using a ground-based EM27/SUN Fourier transform infrared spectrometer (FTIR). The EM27/SUN spectrometers are widely in use in the COllaborative Carbon Column Observing Network (COCCON). The PROFFAST software provided by COCCON has been used to analyze the measured atmospheric solar absorption spectra. In this letter, the diurnal variation and the time series of daily averaged XCO2, XCH4, and XCO covering the period from December 2020 to May 2021 are analyzed. The maximum values of XCO2, XCH4, and XCO are observed to be 420.57 ppm, 1.93 ppm, and 170.40 ppb, respectively. Less diurnal but clear seasonal changes are observed during the study period. XCH4 and XCO from the Sentinel-5Precursor (S5P)/TROPOspheric Monitoring Instrument (TROPOMI) are compared against the EM27/SUN retrievals. The correlation coefficient for the EM27/SUN retrieved XCH4 and XCO, with the S5P/TROPOMI products, are 0.75 and 0.94, respectively. 

Index Terms— EM27/SUN, greenhouse gases (GHGs), Sentinel-5Precursor (S5P)/TROPOspheric Monitoring Instrument (TROPOMI).

IEEE Geoscience and Remote Sensing Letters is a monthly publication for short papers (maximum length 5 pages) addressing new ideas and formative concepts in remote sensing as well as important new and timely results and concepts.

Read full paper: https://ieeexplore.ieee.org/document/9765448