Fig. 1. Ground based hyperspectral FTIR observation system. (a) Fourier transform infrared spectrometer (FTS); (b) solar_tracker

Fig. 2. The Picarro Instrument at Hefei Station

Fig. 3. Variation of CO₂ total columns observed from 2016 to 2017 and comparison with GOSAT satellite data

Fig. 4. Variation of CH₄ total columns observed from 2016 to 2017 and comparison with GOSAT satellite data

Fig. 5. Surface concentration variations of CO₂ from January 2016 to August 2017 observed at Hefei Station

Fig. 6. Surface concentration variations of CH₄ from January 2016 to August 2017 observed at Hefei Station

Fig. 7. The correlation of XCO₂ and XCO observed by ground-based remote sensing at Hefei Station

Fig. 8. The correlation of CO₂ and CO based on in-situ measurements at Hefei Station

Fig. 9. The correlation of XCH₄ and XCO₂ observed by ground-based remote sensing at Hefei Station

Fig. 10. The correlation of CH₄ and CO₂ based on in-situ measurements at Hefei Station