Long range transport of biomass aerosol to Greenland: Multi-spectroscopic investigation of particles deposited in the snow

Abstract

Results are given from the NIST component of a pilot ("winter-over") study of seasonal patterns of natural and anthropogenic species in air and snow transported to Summit, Greenland. Central to this research is the quantitative apportionment of fossil and biomass particulate carbon, based on advanced (micromolar) 14 C accelerator mass spectrometry (AMS) applied to remote snow samples containing as little as 9 µg C/kg. The measurements were made practicable through stringent attention to the nature and sources of the isotopic-chemical blank, resulting in a blank reduction from 5 µg C to <0.5 µg C. An important result of this work is the first evidence of a seasonal pattern in biomass-C particles in Greenland snow. Although 14 C AMS data serve to resolve fossil and biomass carbon quantitatively, a deeper understanding of the aerosol sources and character demands a multidisciplinary approach. This is illustrated with "multi-spectrometric" macro-and micro-analytical data for two cases involving substantial incursions of biomass aerosol to the Summit, Greenland snow.* MDHA (methyl dehydroabietate) is a boreal fire tracer resulting from the pyrolysis of abietic acid in resinous conifers.

Long-term trends of mono-carboxylic acids in Antarctica: comparison of changes in sources and transport processes at the two EPICA deep drilling sites

“…The main sources of carboxylic acids for Central Greenland lie in North America and Asia, from where air trajectories reach the ice cap after a very short track over the North Atlantic, especially over the Arctic Ocean (Kahl et al, 1997). This offers the possibility to better approach the part of the carboxylic cycle related to natural continental sources (biomass burning from the boreal forest, and biomass and soil emission from lower latitudes (Currie et al, 2005). On the contrary, Antarctica is surrounded by a very vast expanse of ocean, so the continental influence remains very restricted under the present climate conditions.…”

A summer time series of particulate carbon in the air and snow at Summit, Greenland

“…Specific organic compounds, including PAHs [ Jaffrezo et al , 1993] and particulate oxalate [ Jaffrezo et al , 1998; Kerminen et al , 1998], have been measured at Summit, Greenland (the highest point of the Greenland Ice Sheet). In addition, major biomass burning episodes impacting the air above the Greenland Ice Sheet were detected through atmospheric measurements of oxalate [ Jaffrezo et al , 1998], 14 C [ Currie et al , 2005], and black carbon [ Stohl et al , 2006]. To our knowledge, there are no other reported measurements of particulate carbonaceous species in the Greenland atmosphere.…”

Snow particles physiochemistry: feedback on air quality, climate change, and human health

“…107 It has been revealed that up to 25% of insoluble aerosols are bioaerosols, 108 which can travel long distances and end up on snow. 109–111 Fig. 3 and 5a–d show some examples of particles, including biological particles of different sizes, from a few nanometers to a few micrometers, in Arctic snow samples.…”