Kamchatka (southeastern Siberia) ice core records of dicarboxylic acids, oxocarboxylic acids and α-dicarbonyls since 1690s: A signal for the tropospheric oxidizing capacity.

There has been much interest about how to identify an ice core signal for oxidizing capacity of the troposphere. This study broadly explains the air-snow transfer/deposition process using ice core records of dicarboxylic (DCAs), ω-oxocarboxylic as well as pyruvic acids and α-dicarbonyls, which are potentially formed by atmospheric oxidation of aromatic hydrocarbons from the continent, incloud-oxidation of isoprene and unsaturated fatty acids from the western North Pacific. An ice core (~152 m long, 304 years) was collected at an ice cap on the Gorshkov crater at the summit of Ushkovsky (56° 04'N, 160° 28'E, altitude: 3903 m) in the Kamchatka Peninsula from southeastern Siberia.

Large contribution of fossil-derived components to aqueous secondary organic aerosols in China.

Incomplete understanding of the sources of secondary organic aerosol (SOA) leads to large uncertainty in both air quality management and in climate change assessment. Chemical reactions occurring in the atmospheric aqueous phase represent an important source of SOA mass, yet, the effects of anthropogenic emissions on the aqueous SOA (aqSOA) are not well constrained. Here we use compound-specific dual-carbon isotopic fingerprints (δC and ΔC) of dominant aqSOA molecules, such as oxalic acid, to track the precursor sources and formation mechanisms of aqSOA.