Source apportionment of Arctic and remote marine carbonaceous aerosols

• Main Author: Rodriguez, Blanca Teresa
• Other Authors: Czimczik, Claudia I
• Format: Thesis
• Language: English
• Published: eScholarship, University of California 2021
• Subjects: Atmospheric chemistry; black carbon; carbon isotopes; organic carbon; radiocarbon; stable carbon; Climate change; Human health; Sea ice
• Online Access: https://escholarship.org/uc/item/51t1q7tv; https://escholarship.org/content/qt51t1q7tv/qt51t1q7tv.pdf

Carbonaceous aerosols are critical, short-lived climate forcers (SLCFs) that play complex roles in the climate system through their interaction with solar radiation, cloud nucleation, and are also a major contributor to air pollution. Globally and within the Arctic, changing aerosol burden associated with the decline of sea ice, shifts in the productivity of marine and terrestrial ecosys-tems, wildfire, and anthropogenic activities, remains an important uncertainty for projections of future climate change. To develop and evaluate effective air quality and climate change mitiga-tion policy, we urgently need a better understanding of emissions sources. An important step forward in unraveling the complexity of carbonaceous aerosols lies in the analysis of specific aerosol fractions that have different emissions sources, lifetimes, and cli-mate- and health impacts. A minor component with significant climate and health implications is black carbon (BC), a light absorbing SLFC emitted directly through incomplete combustion that leads to increased air column temperatures, accelerated ice and snow melt, shifts in cloud for-mation, cover, and lifetime, and have adverse effects on human health. The vast majority are or-ganic carbon (OC) aerosols, that are light-scattering, also emitted through combustion processes, and formed secondarily in the atmosphere. In this thesis, I combine OC/BC analysis with stable (12C, 13C) and radioactive (14C) carbon isotope data to improve our understanding of BC and OC sources (fossil vs. modern and terrestrial vs. marine) and their spatiotemporal variations within the High Arctic, which are considered primarily marine. I also explore aerosol composition in cur-rently understudied marine source regions. Despite significant history of Arctic aerosol monitoring networks and power of isotopic (and specifically 14C data) for source attribution, consistent 14C observations of Arctic aerosol remain sparse. This is largely driven by the small sample sizes of aerosol collected in remote ...