By presenting an approach using EMeRGe-Asia airborne field measurements and surface observations, this study shows that the fraction of OH reactivity due to SO₂-OH reaction has a significant correlation with the sulfate concentration. Approximately 30 % of sulfate is produced by SO₂-OH reaction. Our results underline the importance of SO₂-OH gas-phase oxidation in sulfate formation, and demonstrate that the method can be applied to other regions and under different meteorological conditions.

Column-averaged dry-air mole fractions of CO₂ and CH₄ measured by a solar viewing portable Fourier transform spectrometer (EM27/SUN) were validated with in situ profile data obtained during the transfer flights of two aircraft campaigns. Atmospheric dynamical properties based on ERA5 and WRF-Chem were used as criteria for selecting the best aircraft profiles for the validation. The resulting air-mass-independent correction factors for the EM27/SUN data were 0.9878 for CO₂ and 0.9829 for CH₄.

This study reconstructs drought chronologies of the Qing dynasty (1644–1911) based on Chinese documentary records from the REACHES database. In addition to drought records, ecological and societal records are also retrieved. Tests are performed to cross-check data and time series. Six severe drought periods are identified, and spatial patterns are revealed through multivariable analysis. Drought consequence networks are built highlighting human intervention affecting famine and social turmoil.