Concentrations and Sources of Soot in Greenland Precipitation from 1788 to 2002: Implications for Radiative Forcing
Abstract
Black carbon (BC) in the atmosphere results from biomass and fossil fuel combustion. It alters chemical and physical properties of the atmosphere and snow albedo, yet little is known about BC emission or deposition histories. Monthly resolved measurements of BC in an ice core indicate that concentrations in central Greenland precipitation varied greatly during the period of record from 1788 to 2002. Parallel measurements of vanillic acid and non-sea-salt sulfur in the same ice core suggest that BC in Greenland came from wildfires and industrial activities. Prior to 1850, BC concentrations were highest in late summer to autumn and resulted primarily from boreal forest fires. Beginning about 1850, industrial emissions resulted in a seven-fold increase in ice core BC concentrations, with most change occurring in winter. BC concentrations after about 1951 were lower, probably as a result of wildfire suppression policies and the shift from coal burning to oil and gas in North America. Late 20th century increases in BC, however, may be linked to coal combustion in the rapidly expanding economies of Asia. At its maximum from 1906 to 1910, estimated surface climate forcing in early summer from BC in Arctic snow was about 3 W per square meter, more than eight times typical pre-industrial forcing.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2007
- Bibcode:
- 2007AGUFM.A44B..01M
- Keywords:
-
- 0305 Aerosols and particles (0345;
- 4801;
- 4906);
- 0330 Geochemical cycles (1030);
- 0345 Pollution: urban and regional (0305;
- 0478;
- 4251);
- 0365 Troposphere: composition and chemistry;
- 0394 Instruments and techniques