Analysis of Wildfire Aerosol Aging Using the ASCENT Network Observations

YINGJIE SHEN, Shane Murphy, Jason Surratt, Nicolas Aliaga Buchenau, Jose-Luis Jimenez, Douglas A. Day, Seonsik Yun, Nga Lee Ng, Ann Dillner, Roya Bahreini, Armistead G. Russell, University of Wyoming

     Abstract Number: 721
     Working Group: Carbonaceous Aerosol

Abstract
Black carbon (BC) and Brown carbon (BrC) emissions from wildfires absorb near UV - visible sunlight and impact the global climate. Wildfires are one of the largest sources of both BC and BrC (both primary and secondary), and with the increasing number of wildfires in the United States and globally, the absorption caused by BC and BrC are of growing importance. The contribution of absorption from BC and BrC does not remain constant during their evolution, due to secondary BrC production and photobleaching. However, this evolution process still remains uncertain, largely due to the difficulty of tracking the same fire plume over multiple days of aging and because of variability that is caused by burning conditions versus aging. In this presentation we will present analysis of wildfire aging using measurements from multiple ASCENT (Atmospheric Science and Chemistry mEasurement NeTwork) sites. The ASCENT network consists of 12 sites across the US, which gives us opportunities to keep track of the long-distance transport of the same fire plumes over the country. We will present results on the impact of dilution and physical aging on the contribution of fires to BC and BrC, as well as the relationship of optical properties to aerosol chemical composition.