Occurrence and Properties of Wildfire Aerosol Plumes Measured at the High-Altitude Station Jungfraujoch

BENJAMIN BREM, Nora Nowak, Nicolas Bukowiecki, Martine Collaud Coen, Martin Steinbacher, Martin Vollmer, Stephan Henne, Reimann Stefan, Martin Gysel, Paul Scherrer Institute

     Abstract Number: 631
     Working Group: Aerosols, Clouds and Climate

Abstract
Our history has been a story of how we and fire have co-evolved. The same holds for our future. Wildfires are often not “wild” and can be linked to human activity. Hence, some claim that we are living in the “Pyrocene” [1]. Large-scale biomass burning events emit substantial amounts of primary particulate matter (PM) and gaseous secondary PM precursors. Fractions of these emissions can be injected into the free troposphere where they can be transported over long distances and exhibit a stronger radiative forcing efficiency than at ground level [2]. Large light absorbing carbon concentrations in the free troposphere can also alter the vertical temperature profile, leading to a stratification of the atmosphere below with consequences for clouds and precipitation [3].

This work characterizes the optical and microphysical properties of wildfire plumes transported to the Jungfraujoch (JFJ) Station (3571m a.s.l.). More than thirty wildfire plumes were identified from hourly averaged data for the period between January 2015 and December 2020 using a data screening procedure based on gaseous data and backtrajectories. Plume occurrence frequency, origins and plume optical and chemical properties will be presented at the meeting. In addition, ongoing work investigates changes in plume optical properties with atmospheric processing.

[1] Pyne, S., (2018), J. Fire, 1, 44-49.
[2] Val Martin et al., (2006), Journal of Geophysical Research Atmospheres, 111, 456- 462.
[3] Ban-Weiss et al., (2012), Clim Dyn 38, 897–911.