Document


Title

The size- and time-resolved composition of aerosols from a sub-Arctic boreal forest prescribed burn
Document Type: Journal Article
Author(s): C. F. Cahill; T. A. Cahill; K. D. Perry
Publication Year: 2008

Cataloging Information

Keyword(s):
  • aerosols
  • air quality
  • arctic
  • arctic
  • boreal forests
  • carbon
  • duff
  • ecosystem dynamics
  • fire frequency
  • fire intensity
  • fire management
  • firing techniques
  • forest management
  • fuel accumulation
  • gases
  • impactor
  • K - potassium
  • organic matter
  • sampling
  • smoke effects
  • smoke management
  • soil nutrients
  • watersheds
  • wildfire
  • wildfires
  • wind
Record Maintained By:
Record Last Modified: June 1, 2018
FRAMES Record Number: 47262
Tall Timbers Record Number: 23175
TTRS Location Status: In-file
TTRS Call Number: Fire File
TTRS Abstract Status: Okay, Fair use, Reproduced by permission

This bibliographic record was either created or modified by the Tall Timbers Research Station and Land Conservancy and is provided without charge to promote research and education in Fire Ecology. The E.V. Komarek Fire Ecology Database is the intellectual property of the Tall Timbers Research Station and Land Conservancy.

Description

Aerosols from wildfires are the primary aerosols in the Arctic atmosphere during the summer months. These aerosols occur in large, increasing quantities and impact the sensitive radiative balance in the Arctic. FROSTFIRE, a controlled burn in a Long-Term Ecological Research Area 50 km north of Fairbanks, Alaska, was designed to quantify the impacts of wildfire on sub-Arctic boreal forest ecosystems in permafrost regions. However, it provided a unique opportunity to examine smoke aerosols collected in the middle of a sub-Arctic boreal forest fire. A battery-powered eight-stage aerosol impactor (i.e. a Davis Rotating-drum Unit for Monitoring), mounted at the top of a 10 m meteorological tower in the burn zone, collected size- and time-resolved aerosol samples with 19.45 min resolution for 24 h during the burn. The samples underwent Proton Induced X-ray Emission (PIXE) and Proton Elastic Scattering Analysis (PESA) to determine the sizes and elemental compositions of the collected aerosols. Throughout the fire, the smoke reaching the sampler was strongly monodisperse with most of the aerosol mass in the optically active 0.56-1.15 µm in aerodynamic diameter size range. Fine organics comprised almost all of the mass in this optically active size range and the concentrations of the organics were high throughout the sampling period. However, unlike the fine organics, the potassium concentrations in the smoke decreased exponentially during the sampling period as the fire progressed from an active flaming to a smoldering behavior. The major findings from this field experiment are the dramatic differences in aerosol composition as a function of fire type (i.e. smoldering or active flaming) and that the largest emission of organics occurs during the smoldering phase, unaccompanied by the potassium emissions often used as a smoke tracer. These results agree with recent laboratory experiments. © 2008 Elsevier Ltd. All rights reserved.

Citation:
Cahill, C. F., T. A. Cahill, and K. D. Perry. 2008. The size- and time-resolved composition of aerosols from a sub-Arctic boreal forest prescribed burn. Atmospheric Environment, v. 42, no. 32, p. 7553-7559. 10.1016/j.atmosenv.2008.04.034.