Influences of boreal fire emissions on Northern Hemisphere atmospheric carbon and carbon monoxide

Autor: Jennifer H. Hewson, Lori P. Bruhwiler, Nancy H. F. French, Paul C. Novelli, Eric S. Kasischke, Edward J. Hyer, Brian J. Stocks, A. I. Sukhinin
Rok vydání: 2005
Předmět:
Zdroj: Global Biogeochemical Cycles. 19
ISSN: 0886-6236
Popis: [1] There were large interannual variations in burned area in the boreal region (ranging between 3.0 and 23.6 × 106 ha yr−1) for the period of 1992 and 1995–2003 which resulted in corresponding variations in total carbon and carbon monoxide emissions. We estimated a range of carbon emissions based on different assumptions on the depth of burning because of uncertainties associated with the burning of surface-layer organic matter commonly found in boreal forest and peatlands, and average total carbon emissions were 106–209 Tg yr−1 and CO emissions were 33–77 Tg CO yr−1. Burning of ground-layer organic matter contributed between 46 and 72% of all emissions in a given year. CO residuals calculated from surface mixing ratios in the high Northern Hemisphere (HNH) region were correlated to seasonal boreal fire emissions in 8 out of 10 years. On an interannual basis, variations in area burned explained 49% of the variations in HNH CO, while variations in boreal fire emissions explained 85%, supporting the hypotheses that variations in fuels and fire severity are important in estimating emissions. Average annual HNH CO increased by an average of 7.1 ppb yr−1 between 2000 and 2003 during a period when boreal fire emissions were 26 to 68 Tg CO−1 higher than during the early to mid-1990s, indicating that recent increases in boreal fires are influencing atmospheric CO in the Northern Hemisphere.
Databáze: OpenAIRE
Externí odkaz: