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Hydroxyl and Hydroperoxyyl Radicals: A Model Re-Assessment, Measurements in a Ponderosa Pine Forest, and Indoor-Outdoor Comparison
Hydroxyl and Hydroperoxyyl Radicals: A Model Re-Assessment, Measurements in a Ponderosa Pine Forest, and Indoor-Outdoor Comparison
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20250211153021
- ISBN
- 9798346532569
- DDC
- 551.5
- 서명/저자
- Hydroxyl and Hydroperoxyyl Radicals: A Model Re-Assessment, Measurements in a Ponderosa Pine Forest, and Indoor-Outdoor Comparison
- 발행사항
- [Sl] : Indiana University, 2024
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2024
- 형태사항
- 160 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 86-05, Section: B.
- 주기사항
- Advisor: Stevens, Philip S.
- 학위논문주기
- Thesis (Ph.D.)--Indiana University, 2024.
- 초록/해제
- 요약The hydroxyl radical (OH) controls the lifetime of many trace gases in the atmosphere and initiates the chemistry that can lead to the production of secondary pollutants harmful to human health and the environment such as aerosols and tropospheric ozone. The OH radical oxidizes volatile organic compounds (VOCs) to propagate a radical cycle which forms organic peroxy radicals (RO2) that react with nitric oxide (NO) to form hydroperoxyl radicals (HO2) which react with NO to re-form OH. Due to the short lifetime of these radicals, they can be very difficult to measure. Yet, accurate measurements of OH and HO2 are necessary in order to test the understanding of radical chemistry in models. Historically, a model-measurement discrepancy has driven the study of the OH radical, especially in rural areas. However, an analysis presented here demonstrates that the model understanding of OH chemistry generally reproduces measured concentrations. This is in contrast to the variable model-measurement agreement for HO2.One environment where HO2 has been underpredicted by models is in the ponderosa pine forest. In this forest, 2-methyl-3-buten-2-ol (MBO) is the dominant biogenic VOC (BVOC) released. Here, a missing HO2 source is most likely attributed to the fate of MBO and oxidized MBO products which are largely understudied. Additionally, when sesquiterpenes are added as a model constraint the model first-order lifetime needed to be decreased from 24 hours to 30 minutes in order for the modeled OH reactivity to reproduce the measured OH reactivity. This result revealed that sesquiterpenes are also an understudied class of chemicals with respect to their atmospheric fate.Finally, similar to the outdoor environment, HOx (OH + HO2) radicals can be responsible for generating indoor air pollutants such as O3 and secondary organic aerosols which are harmful to human health. For the first time, the influence of outdoor radicals on the unperturbed indoor environment is evaluated through concurrent measurements of HO2. Initial results reveal that the lifetime of HO2 outdoors is most likely too short for an indoor influence. However, correlations of NO and O3 indicate potential of outdoor air transport inside to influence radical chemistry indoors.
- 일반주제명
- Atmospheric chemistry
- 일반주제명
- Environmental science
- 일반주제명
- Atmospheric sciences
- 키워드
- Hydroxyl radical
- 키워드
- Ponderosa pine
- 키워드
- Nitric oxide
- 기타저자
- Indiana University Environmental Science
- 기본자료저록
- Dissertations Abstracts International. 86-05B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
008250123s2024 us c eng d■001000017164602
■00520250211153021
■006m o d
■007cr#unu||||||||
■020 ▼a9798346532569
■035 ▼a(MiAaPQ)AAI31632080
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a551.5
■1001 ▼aPrice, Paige McKenzie.
■24510▼aHydroxyl and Hydroperoxyyl Radicals: A Model Re-Assessment, Measurements in a Ponderosa Pine Forest, and Indoor-Outdoor Comparison
■260 ▼a[Sl]▼bIndiana University▼c2024
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2024
■300 ▼a160 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 86-05, Section: B.
■500 ▼aAdvisor: Stevens, Philip S.
■5021 ▼aThesis (Ph.D.)--Indiana University, 2024.
■520 ▼aThe hydroxyl radical (OH) controls the lifetime of many trace gases in the atmosphere and initiates the chemistry that can lead to the production of secondary pollutants harmful to human health and the environment such as aerosols and tropospheric ozone. The OH radical oxidizes volatile organic compounds (VOCs) to propagate a radical cycle which forms organic peroxy radicals (RO2) that react with nitric oxide (NO) to form hydroperoxyl radicals (HO2) which react with NO to re-form OH. Due to the short lifetime of these radicals, they can be very difficult to measure. Yet, accurate measurements of OH and HO2 are necessary in order to test the understanding of radical chemistry in models. Historically, a model-measurement discrepancy has driven the study of the OH radical, especially in rural areas. However, an analysis presented here demonstrates that the model understanding of OH chemistry generally reproduces measured concentrations. This is in contrast to the variable model-measurement agreement for HO2.One environment where HO2 has been underpredicted by models is in the ponderosa pine forest. In this forest, 2-methyl-3-buten-2-ol (MBO) is the dominant biogenic VOC (BVOC) released. Here, a missing HO2 source is most likely attributed to the fate of MBO and oxidized MBO products which are largely understudied. Additionally, when sesquiterpenes are added as a model constraint the model first-order lifetime needed to be decreased from 24 hours to 30 minutes in order for the modeled OH reactivity to reproduce the measured OH reactivity. This result revealed that sesquiterpenes are also an understudied class of chemicals with respect to their atmospheric fate.Finally, similar to the outdoor environment, HOx (OH + HO2) radicals can be responsible for generating indoor air pollutants such as O3 and secondary organic aerosols which are harmful to human health. For the first time, the influence of outdoor radicals on the unperturbed indoor environment is evaluated through concurrent measurements of HO2. Initial results reveal that the lifetime of HO2 outdoors is most likely too short for an indoor influence. However, correlations of NO and O3 indicate potential of outdoor air transport inside to influence radical chemistry indoors.
■590 ▼aSchool code: 0093.
■650 4▼aAtmospheric chemistry
■650 4▼aEnvironmental science
■650 4▼aAtmospheric sciences
■653 ▼aHydroperoxyl radicals
■653 ▼aHydroxyl radical
■653 ▼aPonderosa pine
■653 ▼aNitric oxide
■690 ▼a0371
■690 ▼a0768
■690 ▼a0725
■71020▼aIndiana University▼bEnvironmental Science.
■7730 ▼tDissertations Abstracts International▼g86-05B.
■790 ▼a0093
■791 ▼aPh.D.
■792 ▼a2024
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17164602▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.


