Anthropogenic emissions during Arctas-A: mean transport characteristics and regional case studies

• Published in: Atmospheric Chemistry and Physics
• Main Authors: D. L. Harrigan, H. E. Fuelberg, I. J. Simpson, D. R. Blake, G. R. Carmichael, G. S. Diskin
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2011
• Subjects: Physics; QC1-999; Chemistry; QD1-999; Arctic; International Polar Year; IPY; Alaska
• Online Access: https://doi.org/10.5194/acp-11-8677-2011; https://doaj.org/article/95793bf9837a4d60b457957af8784314

The National Aeronautics and Space Administration (NASA) conducted the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission during 2008 as a part of the International Polar Year (IPY). The purpose of ARCTAS was to study the factors responsible for changes in the Arctic's atmospheric composition and climate. A major emphasis was to investigate Arctic haze, which is most pronounced during winter and early spring. This study focuses on the spring phase of ARCTAS (ARCTAS-A) that was based in Alaska during April 2008. Although anthropogenic emissions historically have been associated with Arctic haze, biomass burning emissions dominated the ARCTAS-A period and have been the focus of many ARCTAS related studies. This study determines mean transport characteristics of anthropogenic emissions during ARCTAS-A. Trajectories are initiated each day from three significant regions of anthropogenic emissions (Asia, North America, and Europe). The fifteen day forward trajectories are calculated using data from the Weather Research and Forecasting (WRF) model at 45 km horizontal resolution. The trajectory calculations indicate: origins of emissions that reach the Arctic (defined as north of 70° N) within fifteen days, pathways of these emissions, Arctic entry locations, and altitudes at which the trajectories enter the Arctic. Three cases during the ARCTAS-A period (one for each of the regions above) are examined using backward trajectories and chemical fingerprinting based on in situ data sampled from the NASA DC-8. The fingerprinting utilizes volatile organic compounds that represent pure anthropogenic tracers, Asian anthropogenic pollution, incomplete combustion, and natural gas emissions. We determine flight legs containing anthropogenic emissions and the pathways travelled by these emissions. Results show that the DC-8 sampled anthropogenic emissions from Asia, North America, and Europe during the spring phase of ARCTAS. The pathways travelled by these emissions agree with our ...