Over a decade (2013-2022) near Hyderabad, India, continuous measurements of CO₂ and CH₄ were conducted under the ISRO-GBP at NRSC lab, calibrated against NOAA standards. Results show an annual atmospheric CO₂ growth rate of 2.63 ppm/year and CH₄ growth rate of 17 ppb/year during the period.

Statistical modeling extracted inter-annual, seasonal, and residual components from the data. CO₂ growth rates were influenced by terrestrial biosphere activity and El Nino-Southern Oscillation (ENSO), with a notable spike of 5.5 ppm/year in 2017 attributed to the extended El Nino phase during 2015-2016. Vegetative indexes were linked to CO₂ and CH₄ concentration variability at the site, indicating that CO₂ fluctuations are associated with photosynthesis, biogenic respiration, and local/long-range anthropogenic influences. This study sheds light on the complex factors contributing to atmospheric CO₂ and CH₄ variations in the region.

This study provides a decade-long dataset of high-precision surface-level atmospheric CO₂ and CH₄ concentrations in Central India. Key findings include annual growth rates of 2.63 ppm for CO₂ and 17 ppb for CH₄ from 2013 to 2022.

Unlike CO₂ , CH₄ sources and residency times differ, with potential for quicker decreases if emissions stabilize. Analysis of column CO₂ from OCO-2 mirrors global trends, with a range from 395 ppm in October 2014 to 418 ppm in May 2021. The study links site-specific combustion and terrestrial biosphere activity to variations in atmospheric CO₂ and CH₄ mixing ratios during the study period

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Fig. Atmospheric CO₂ from the space-based multi-sensors and overlaid on in situ observations recorded at Shadnagar site during 2003–2022

Fig. Ten-year [2013–2022] time series of seasonal atmospheric a) CO₂ and b) CH₄ concentrations and their respective seasonal cycles measured at NRSC, Shadnagar c) OCO-2 measured columnar CO₂ during 2014–2022