{"id":{"repo_id":"woods-hole","oai_identifier":"oai:darchive.mblwhoilibrary.org:1912/69779"},"canonical_url":"https://search.dev.ndltd.org/etd/woods-hole/oai:darchive.mblwhoilibrary.org:1912/69779","repository":{"repo_id":"woods-hole","name":"Woods Hole Oceanographic Institute","base_url":"https://darchive.mblwhoilibrary.org/server/oai/request"},"display":{"title":"Quantifying the effects of sunlight on the fate of oil spilled at sea","abstract":"Oil spilled at sea is transformed by sunlight-driven photochemical reactions. The transformed oil has different properties and behavior in the environment compared to the fresh oil, resulting in different fates and effects. My work in this thesis was to put numbers on these changes, with the goal of better predicting where oil goes and how it behaves in diverse spill scenarios. First, I focused on how sunlight generates water-soluble compounds from oil, which can lead to the dissolution of oil-derived compounds in seawater (photo-dissolution; Chapter 2). To find out whether photo-dissolution could be an important fate process during an oil spill, I used a combination of experiments and photochemical rate modeling to calculate photo-dissolution rates for the 2010 Deepwater Horizon spill (DwH) in the Gulf of Mexico (GoM). I found that photodissolution likely converted ~8% of the floating surface oil to dissolved organic carbon during DwH, a fraction similar in magnitude to other well-recognized fate processes. Moving beyond DwH, I evaluated the sensitivity of oil photo-dissolution and photochemically-altered oil physical properties to temperature. I found that if a spill like DwH had occurred in 5°C water rather than the exceptionally warm 30°C water of the GoM, 7x less oil could have dissolved via photodissolution and the viscosity of the remaining insoluble oil could have been 16x higher, resulting in lower entrainment of oil into the water column as small droplets (Chapter 3). The net result is that more oil would stay at the sea surface in a cold-water spill. Finally, I determined photodissolution rates for diverse oil products beyond the light crude that spilled during DwH (Chapter 4). I found that oil photo-reactivity could be predicted from oil chemical composition. I also found that photo-dissolution likely affects oil mass balance in spills of light oils forming thin slicks but not in spills of light or heavy oils forming thick slicks. Overall, this work advances our understanding of how oil changes in the environment upon sunlight exposure. This information can be applied to better predict, evaluate, and mitigate the effects of oil spilled at sea on marine ecosystems, including humans.","abstract_html":"Oil spilled at sea is transformed by sunlight-driven photochemical reactions. The transformed oil has different properties and behavior in the environment compared to the fresh oil, resulting in different fates and effects. My work in this thesis was to put numbers on these changes, with the goal of better predicting where oil goes and how it behaves in diverse spill scenarios. First, I focused on how sunlight generates water-soluble compounds from oil, which can lead to the dissolution of oil-derived compounds in seawater (photo-dissolution; Chapter 2). To find out whether photo-dissolution could be an important fate process during an oil spill, I used a combination of experiments and photochemical rate modeling to calculate photo-dissolution rates for the 2010 Deepwater Horizon spill (DwH) in the Gulf of Mexico (GoM). I found that photodissolution likely converted ~8% of the floating surface oil to dissolved organic carbon during DwH, a fraction similar in magnitude to other well-recognized fate processes. Moving beyond DwH, I evaluated the sensitivity of oil photo-dissolution and photochemically-altered oil physical properties to temperature. I found that if a spill like DwH had occurred in 5°C water rather than the exceptionally warm 30°C water of the GoM, 7x less oil could have dissolved via photodissolution and the viscosity of the remaining insoluble oil could have been 16x higher, resulting in lower entrainment of oil into the water column as small droplets (Chapter 3). The net result is that more oil would stay at the sea surface in a cold-water spill. Finally, I determined photodissolution rates for diverse oil products beyond the light crude that spilled during DwH (Chapter 4). I found that oil photo-reactivity could be predicted from oil chemical composition. I also found that photo-dissolution likely affects oil mass balance in spills of light oils forming thin slicks but not in spills of light or heavy oils forming thick slicks. Overall, this work advances our understanding of how oil changes in the environment upon sunlight exposure. This information can be applied to better predict, evaluate, and mitigate the effects of oil spilled at sea on marine ecosystems, including humans.","abstract_has_math":false,"creators":["Freeman, Danielle Haas"],"institution":"Massachusetts Institute of Technology and Woods Hole Oceanographic Institution","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Ward, Collin P."],"committee_chairs":[],"committee_members":[],"year":2024,"date_issued":"2024-09","date_published":"2024-09","updated_at":"2026-07-27T22:05:04Z","subjects":["Oil spills","Photochemistry","Dissloved organic carbon"],"languages":["en_US"],"rights":["©2024 Danielle Haas Freeman. The author hereby grants to MIT and WHOI a nonexclusive, worldwide, irrevocable, royalty-free license to exercise any and all rights under copyright, including to reproduce, preserve, distribute and publicly display copies of the thesis, or release the thesis under an open-access license."],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier.doi","label":"DOI","values":["10.1575/1912/69779"],"render_values":[{"text":"10.1575/1912/69779","href":"https://doi.org/10.1575/1912/69779","code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/1912/69779","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Ward, Collin P."]},{"key":"dc:creator","label":"Author","values":["Freeman, Danielle Haas"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2024-07-17T21:10:06Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2024-07-17T21:10:06Z"]},{"key":"dc:date.issued","label":"Date","values":["2024-09"]},{"key":"dc:publisher","label":"Institution","values":["Massachusetts Institute of Technology and Woods Hole Oceanographic Institution"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Oil spills","Photochemistry","Dissloved organic carbon"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en_US"]},{"key":"dc:rights","label":"Dc Rights","values":["©2024 Danielle Haas Freeman. The author hereby grants to MIT and WHOI a nonexclusive, worldwide, irrevocable, royalty-free license to exercise any and all rights under copyright, including to reproduce, preserve, distribute and publicly display copies of the thesis, or release the thesis under an open-access license."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.doi","label":"DOI","values":["10.1575/1912/69779"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/1912/69779"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Environmental Chemistry at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2024."]},{"key":"dc:description.abstract","label":"Abstract","values":["Oil spilled at sea is transformed by sunlight-driven photochemical reactions. The transformed oil has different properties and behavior in the environment compared to the fresh oil, resulting in different fates and effects. My work in this thesis was to put numbers on these changes, with the goal of better predicting where oil goes and how it behaves in diverse spill scenarios. First, I focused on how sunlight generates water-soluble compounds from oil, which can lead to the dissolution of oil-derived compounds in seawater (photo-dissolution; Chapter 2). To find out whether photo-dissolution could be an important fate process during an oil spill, I used a combination of experiments and photochemical rate modeling to calculate photo-dissolution rates for the 2010 Deepwater Horizon spill (DwH) in the Gulf of Mexico (GoM). I found that photodissolution likely converted ~8% of the floating surface oil to dissolved organic carbon during DwH, a fraction similar in magnitude to other well-recognized fate processes. Moving beyond DwH, I evaluated the sensitivity of oil photo-dissolution and photochemically-altered oil physical properties to temperature. I found that if a spill like DwH had occurred in 5°C water rather than the exceptionally warm 30°C water of the GoM, 7x less oil could have dissolved via photodissolution and the viscosity of the remaining insoluble oil could have been 16x higher, resulting in lower entrainment of oil into the water column as small droplets (Chapter 3). The net result is that more oil would stay at the sea surface in a cold-water spill. Finally, I determined photodissolution rates for diverse oil products beyond the light crude that spilled during DwH (Chapter 4). I found that oil photo-reactivity could be predicted from oil chemical composition. I also found that photo-dissolution likely affects oil mass balance in spills of light oils forming thin slicks but not in spills of light or heavy oils forming thick slicks. Overall, this work advances our understanding of how oil changes in the environment upon sunlight exposure. This information can be applied to better predict, evaluate, and mitigate the effects of oil spilled at sea on marine ecosystems, including humans."]},{"key":"dc:title","label":"Title","values":["Quantifying the effects of sunlight on the fate of oil spilled at sea"]}]}],"canonical_facts":{"dc:contributor.advisor":["Ward, Collin P."],"dc:creator":["Freeman, Danielle Haas"],"dc:date.accessioned":["2024-07-17T21:10:06Z"],"dc:date.available":["2024-07-17T21:10:06Z"],"dc:date.issued":["2024-09"],"dc:description":["Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Environmental Chemistry at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2024."],"dc:description.abstract":["Oil spilled at sea is transformed by sunlight-driven photochemical reactions. The transformed oil has different properties and behavior in the environment compared to the fresh oil, resulting in different fates and effects. My work in this thesis was to put numbers on these changes, with the goal of better predicting where oil goes and how it behaves in diverse spill scenarios. First, I focused on how sunlight generates water-soluble compounds from oil, which can lead to the dissolution of oil-derived compounds in seawater (photo-dissolution; Chapter 2). To find out whether photo-dissolution could be an important fate process during an oil spill, I used a combination of experiments and photochemical rate modeling to calculate photo-dissolution rates for the 2010 Deepwater Horizon spill (DwH) in the Gulf of Mexico (GoM). I found that photodissolution likely converted ~8% of the floating surface oil to dissolved organic carbon during DwH, a fraction similar in magnitude to other well-recognized fate processes. Moving beyond DwH, I evaluated the sensitivity of oil photo-dissolution and photochemically-altered oil physical properties to temperature. I found that if a spill like DwH had occurred in 5°C water rather than the exceptionally warm 30°C water of the GoM, 7x less oil could have dissolved via photodissolution and the viscosity of the remaining insoluble oil could have been 16x higher, resulting in lower entrainment of oil into the water column as small droplets (Chapter 3). The net result is that more oil would stay at the sea surface in a cold-water spill. Finally, I determined photodissolution rates for diverse oil products beyond the light crude that spilled during DwH (Chapter 4). I found that oil photo-reactivity could be predicted from oil chemical composition. I also found that photo-dissolution likely affects oil mass balance in spills of light oils forming thin slicks but not in spills of light or heavy oils forming thick slicks. Overall, this work advances our understanding of how oil changes in the environment upon sunlight exposure. This information can be applied to better predict, evaluate, and mitigate the effects of oil spilled at sea on marine ecosystems, including humans."],"dc:identifier.doi":["10.1575/1912/69779"],"dc:identifier.uri":["https://hdl.handle.net/1912/69779"],"dc:language.iso":["en_US"],"dc:publisher":["Massachusetts Institute of Technology and Woods Hole Oceanographic Institution"],"dc:rights":["©2024 Danielle Haas Freeman. The author hereby grants to MIT and WHOI a nonexclusive, worldwide, irrevocable, royalty-free license to exercise any and all rights under copyright, including to reproduce, preserve, distribute and publicly display copies of the thesis, or release the thesis under an open-access license."],"dc:subject":["Oil spills","Photochemistry","Dissloved organic carbon"],"dc:title":["Quantifying the effects of sunlight on the fate of oil spilled at sea"],"dc:type":["Thesis"]},"updated_at":"2026-07-27T22:05:04Z"}