HR: 0800h
AN: A51D-0109    [Abstracts]
TI: Impact of Large-Scale Boreal Fires on Levels of Tropospheric Ozone in the Northern Hemisphere
AU: * Lapina, K
EM: klapina@mtu.edu
AF: Civil and Environmental Eng. Dpt., Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931
AU: Honrath, R
EM: reh@mtu.edu
AF: Civil and Environmental Eng. Dpt., Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931
AU: Owen, C
EM: rcowen@mtu.edu
AF: Civil and Environmental Eng. Dpt., Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931
AU: Val Martin, M
EM: mvalmart@mtu.edu
AF: Civil and Environmental Eng. Dpt., Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931
AU: Strane, J
EM: jmstrane@mtu.edu
AF: Civil and Environmental Eng. Dpt., Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931
AB: We present an analysis of ozone and carbon monoxide measurements in the central N. Atlantic lower free troposphere that is designed to determine the impact of boreal wildfire emissions on ozone levels in distant downwind regions. Measurements were made at the PICO-NARE mountaintop station (2225 m asl) in the Azores Islands. The station is frequently impacted by outflow from high-latitude regions where fires are common in the summer. Here, we use summer observations of ozone and carbon monoxide made in 2001, 2003, and 2004, to assess the impact of boreal forest fires on the distribution of ozone mixing ratios at this location. Using HYSPLIT backward trajectories, we selected time periods during which transport from boreal regions occurred. These periods were then further segregated into two subsets: periods with and periods without significant upwind fire emissions, using enhanced CO as an indicator of fire-affected flow. Through comparison of the resulting ozone distributions, we deduce that emissions from boreal fires led to significant ozone production. It is likely that this production was partly or largely responsible for significant shifts in the ozone distribution toward higher mixing ratios during 2003 (due to Siberian fires) and 2004 (due to Alaskan and Canadian fires). Global circulation model (GCM) simulations predict increased boreal fire danger resulting from global climate change in future decades. Our analyses imply that increased boreal fire magnitudes would enhance the summertime ozone background over large regions of Northern Hemisphere, providing a climate feedback (as ozone is a greenhouse gas) and negatively affecting the ability of downwind nations to meet ozone air quality standards.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
DE: 1630 Impacts of global change (1225)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005