Evolution and Multidisciplinary Frontiers of¹⁴C Aerosol Science

Abstract

ABSTRACT.A review is given of some critical events in the development of radiocarbon aerosol science, and the profound influence of radiocarbon accelerator mass spectrometry (AMS) on its current applications and future prospects. The birth of this discipline occurred shortly after the initial development of 14 C dating. Unlike dating, which is founded on the continual decay of 14 C and the resulting full range of 14 C/ 12 C ratios in once-living matter, 14 C applications to atmospheric aerosol research relate primarily to the determination of mixing ratios of fossil and biomass components. Such determinations have come to have major importance in work ranging from the resolution of woodburning and motor vehicle components of urban particulate pollution, to the apportionment of radiation-forcing (black) particulate carbon from natural wildfires and anthropogenic regional plumes. The development of this area has paralleled that of AMS itself, with the one or the other alternately serving as the driving force, in a sort of counterpoint. The remarkable million-fold improvement in sensitivity made possible by AMS has become critical in meeting rapidly emerging societal concerns with the origins and effects of individual carbonaceous species on health and climate.

Wet deposition of fossil and non-fossil derived particulate carbon: Insights from radiocarbon measurement

“…Wet deposition is known to be a key 27 scavenging (removing) process of carbonaceous particles (Fig. 1) of the large age of this material (Currie, 2000). 41…”

Radiocarbon Analysis of Carbonaceous Aerosols: Recent Developments

“…[12,23] This technique detects disintegrations of radioactive nuclide so that the efficiency of this process decreases linearly with the extension of the half-life for a given activity and measurement time. On the other hand, mass spectrometric techniques detect radio- Radiocarbon analysis allows fossil and non-fossil sources of BC (equivalent to EC) and OC to be identified.…”

“…For a long time, aerosol samples were prepared for 14 C measurement exclusively by total combustion of air filters, [12,16,17] as this is, in general, a preferential technique for 14 C analysis due to its simplicity. At the start of the work in the laboratory at University of Bern, the idea of source apportionment of carbonaceous aerosols differentiated into OC and EC made necessary several analytical and technical developments:…”

“…[12] Studies from Los Angeles and Denver in the 1980s and 1990s showed that TC may originate from fossil sources by up to >70% in large U.S. cities. [16,17] Zurich and Gothenburg as European urban sites show smaller fossil contributions of ~50%, [14,15,22] which are only slightly higher than for most of the investigated European rural sites.…”

“…[8][9][10][11] Here, radiocarbon ( 14 C) analysis of carbonaceous aerosols is an important and powerful tool. [12,13] As shown in Fig. 1, 14 C is used for source apportionment of carbonaceous aerosols due to the contrasting 14 C values of modern and fossil materials.…”