GESTAR II Seminar Series, Thursday, November 13th, 11:00am
We hope you will join us for our final talk of the year, a virtual seminar by Dr. Solomon Bililign, Professor, Department of Physics, North Carolina Agricultural and Technical State University (NCA&T). His talk is titled "Characterizing the Optical and Chemical Properties of Aerosols Derived from Sub-Saharan African Biomass Fuels: Laboratory and Field Studies."
Date and Time: Thursday, November 13, 2025 at 11:00am EST
Join us via Teams.
Abstract:
"Wildfires are increasingly frequent and intense. African fires account for over 50% of worldwide biomass burning (BB)-derived organic emissions and sub-Saharan Africa is a hotspot for BB-derived carbonaceous aerosols, including light-absorbing organic (brown) carbon (BrC). These aerosols play a significant, yet uncertain, role in modulating the Earth’s radiation balance. However, accurately representing their optical properties in climate models remains challenging due to factors such as particle size, mixing state, combustion type, chemical composition, aging processes, and relative humidity (RH). Furthermore, the chemically complex nature of BrC in BB aerosols from this region is not fully understood.
Over the last five years, in collaboration with the UNC-CH (Chapel Hill) team, we used the NCAT facility (tube furnace, smog chamber, etc.) to generate smoke through smoldering combustion of common sub-Saharan African biomass fuels (hardwoods, cow dung, savanna grass, and leaves), collected filter samples from the region, and used the UNC biomarker facility and labs for chemical characterization to investigate: (1) key optical parameters accounting for variations in wavelength, fuel type, RH, and photochemical aging conditions; (2) molecular tracers of BB-derived organic aerosols in fresh versus photochemically aged BB emissions representative of African fires; (3) molecular-level absorbance and chemical composition of filter-collected BB aerosols; (4) compositionally-resolved mass concentration and production of primary and secondary organic aerosols; and, (5) chemically characterized primary water-soluble organic gas emissions from laboratory burns using mist chamber samplers to mimic cloud water and characterized their decompositions in cloud water mimics upon aqueous-phase photochemical oxidation.
We present the main results of these studies and their atmospheric relevance and implications to global atmospheric composition."
Biography:
Dr. Solomon Bililign joined NCA&T in 1993. He did his undergraduate and MS work in Physics at Addis Ababa University, Ethiopia, his PhD work at the University of Iowa, and his postdoctoral research fellowship at the University of Utah Department of Chemistry. His area of specialization includes Experimental and Theoretical Atomic, Molecular and Optical Physics /and Chemical Physics. He built research capacity in chemical physics and atmospheric sciences at NCA&T with a combined federal grant of over $23 million. He served as the Department Chair of Physics from 2001-2006.
Honors and Awards:
1. Recipient of the Presidential Award for Excellence in Science, Math and Engineering Mentoring- 2010
2. NCAT senior researcher award for NCAT in 2002 and 2017
3. NCAT Interdisciplinary research team award in 2012
4. College Teaching excellence award in 2006, 2015 and 2018
5. Alumni Fellows of College of Liberal Arts and Sciences, The University of Iowa, 2010
6. Nominee for AGU Fellow 2022
7. Fulbright Scholar 2024-2025
For more information on the GESTAR II Seminar Series, click here.
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Posted: November 10, 2025, 4:12 PM
