Download or read book Marine Reactive Trace Gases and Their Impacts on Atmospheric Chemistry in the Marine Boundary Layer written by Delaney Brenna Kilgour and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ocean is a globally significant source of reactive trace gases to the atmosphere, including volatile organic compounds (VOC) and organosulfur molecules like dimethyl sulfide (DMS) and methanethiol (MeSH). The emission and oxidation of these reactive trace gases control oxidant loadings, the formation and growth of secondary aerosol to cloud condensation nuclei sizes, and cloud properties in the marine atmosphere. Recent research has demonstrated an increased variety of trace gases beyond DMS produced via biological, heterogeneous, and photochemical mechanisms at the ocean surface. Additionally, findings within the last five years have shown the dominant impact of multiphase processes on dictating how oceanic emissions of DMS influence climate. This thesis work aims to provide constraints on the composition and yields of marine reactive trace gases produced via biological and heterogeneous oxidation pathways, and insights into their subsequent atmospheric processing and climate impacts through a combination of flow tube, wave channel, and field measurements and box modelling. Particular attention is given to the relative impacts of non-DMS reactive trace gases and the role of cloud processing in controlling the global sulfur budget.Chapter 2 examines the production and emission of organosulfur molecules as a function of ocean biogeochemical variables, with specific focus on MeSH, relative to DMS, during an induced phytoplankton bloom on coastal seawater at the Scripps Institution of Oceanography wave channel. This work shows MeSH is a large contributor to the marine gas-phase sulfur budget and should be included in future global model analyses to accurately portray the production of sulfur dioxide and sulfate aerosol. Chapter 3 describes a set of laboratory experiments probing the production of VOC from ozonolysis of the sea surface microlayer. Yields and chemical composition of VOC are reported and interpreted within the context of analogous measurements of VOC and O3 fluxes from Scripps Pier in La Jolla, California, where the seawater was collected. This work demonstrates that abiotic VOC production can be a significant reactive carbon source to the marine atmosphere even at the lower limit of measured yields. Chapter 4 reports the first collocated measurements of speciated monoterpenes and aerosol chemical composition in the remote marine atmosphere. This dataset reveals that despite their high reactivity and yields of secondary organic aerosol, monoterpenes are a minor contributor to secondary aerosol, relative to the sulfur species, DMS and MeSH, and other measured organics during this study. Lastly, Chapter 5 utilizes collocated measurements of the precursor DMS and oxidized, soluble product hydroperoxymethyl thioformate (HPMTF) to derive the loss rates of HPMTF to boundary layer cloud. This analysis suggests low-level clouds are the controlling variable setting the sulfur budget in this region of the Eastern North Atlantic during the study, and act even more efficiently than what is currently prescribed in global models. By acting as an efficient sink of HPMTF, clouds strongly regulate the production of sulfur dioxide, carbonyl sulfide, and sulfate aerosol. Collectively, the products of this thesis work provide constraints on marine reactive trace gas production, emission, and atmospheric processing to better inform global climate models.