Chemical Characterization of Isoprene- and Monoterpene-Derived SOA Tracers in Marine Aerosols from the Galápagos Islands

Atmospheric fine particulate matter plays a critical role in the global climate system and oceans are an important source. The Galápagos Islands present a pristine environment to investigate the sources of marine PM2.5. This study presents a month of meteorological data and real-time PM2.5 mass and discrete PM2.5 chemical measurements. PM2.5 samples collected onto high-volume quartz filters were chemically characterized using a hydrophilic interaction liquid chromatography method interfaced with electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (HILIC/ESI-HR-QTOFMS). PM2.5 organic constituents showed a medium correlation with both marine and terrestrial tracers. The data also shows, for the first time, evidence of isoprene- and monoterpene-derived SOA on the Galápagos Islands. Approximately 3% of the total particulate organic carbon (OC) on the filters was quantified. Our work demonstrates the feasibility for the Galápagos Islands as a location for collection and speciation of marine aerosols. However, future work should address larger sources of OC.Master of Scienc