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Understanding Forced Pacific Climate Responses With Large Ensembles
Understanding Forced Pacific Climate Responses With Large Ensembles
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20260202105150
- ISBN
- 9798297664210
- DDC
- 363
- 저자명
- Xing, Chen.
- 서명/저자
- Understanding Forced Pacific Climate Responses With Large Ensembles
- 발행사항
- [Sl] : University of California, Santa Barbara, 2025
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2025
- 형태사항
- 192 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 87-04, Section: B.
- 주기사항
- Advisor: Stevenson, Samantha.
- 학위논문주기
- Thesis (Ph.D.)--University of California, Santa Barbara, 2025.
- 초록/해제
- 요약Human activities reshape the climate system by altering both the mean state and its variability. The Pacific-home to the Pacific Decadal Variability (PDV), and the El Nino-Southern Oscillation (ENSO)-mediates global hydroclimate and regional temperature-precipitation patterns, yet the forced component of these modes remains contested. This dissertation uses large ensembles, including single-forcing experiments, to cleanly separate externally forced responses from internal variability and to clarify mechanisms relevant for projection.First, I evaluate PDV diagnostics and evaluate PDV response to anthropogenic forcing. Comparing three common methods, I show that the widely used approach that removes only the global mean sea surface temperature (SST) aliases evolving mean state trends into PDV, falsely implying a strong forced response. When mean state change is represented by the ensemble mean-capturing its spatial structure and temporal evolution-there is no significant forced change in PDV modes.Second, I assess solar radiation management (SRM) influence on ENSO. In idealized experiments, subtropical Pacific marine cloud brightening (MCB) reduces ENSO variance by roughly two-thirds, whereas stratospheric aerosol injection has minimal effect. A mixed layer heat budget analysis links the ENSO suppression to a La Nina-like mean state: cloud induced shortwave reductions cool the southeastern Pacific, strengthen easterlies, steepen the zonal thermocline tilt, and weaken the Bjerknes feedback. Given ENSO's central role in global hydroclimate and ecosystems, such suppression carries substantial risks.Third, I quantify changes in global marine heatwaves (MHWs) intensity. By late century, increases in MHW intensity are dominated by mean SST warming, with internal variability playing a minor role. Motivated by recent "Blob" events, I then examine the Northeastern Pacific SST trend. Single-forcing ensembles indicate aerosol forcing dominated the SST trend before ~1980, greenhouse gases thereafter, and that the recent (2009-2025) abrupt warming is primarily an expression of internal variability rather than a direct consequence of recent Chinese aerosol reductions.Together, this work implies that accurate representation of the mean state is critical for credible assessments of climate variability and for robust model-observation evaluation.
- 일반주제명
- Climate change
- 일반주제명
- Atmospheric sciences
- 일반주제명
- Physical oceanography
- 일반주제명
- Geophysics
- 키워드
- Climate dynamics
- 키워드
- Climate modeling
- 키워드
- Marine heatwaves
- 기타저자
- University of California, Santa Barbara Environmental Science & Management
- 기본자료저록
- Dissertations Abstracts International. 87-04B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■00520260202105150
■006m o d
■007cr#unu||||||||
■020 ▼a9798297664210
■035 ▼a(MiAaPQ)AAI32242081
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a363
■1001 ▼aXing, Chen.
■24510▼aUnderstanding Forced Pacific Climate Responses With Large Ensembles
■260 ▼a[Sl]▼bUniversity of California, Santa Barbara▼c2025
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2025
■300 ▼a192 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 87-04, Section: B.
■500 ▼aAdvisor: Stevenson, Samantha.
■5021 ▼aThesis (Ph.D.)--University of California, Santa Barbara, 2025.
■520 ▼aHuman activities reshape the climate system by altering both the mean state and its variability. The Pacific-home to the Pacific Decadal Variability (PDV), and the El Nino-Southern Oscillation (ENSO)-mediates global hydroclimate and regional temperature-precipitation patterns, yet the forced component of these modes remains contested. This dissertation uses large ensembles, including single-forcing experiments, to cleanly separate externally forced responses from internal variability and to clarify mechanisms relevant for projection.First, I evaluate PDV diagnostics and evaluate PDV response to anthropogenic forcing. Comparing three common methods, I show that the widely used approach that removes only the global mean sea surface temperature (SST) aliases evolving mean state trends into PDV, falsely implying a strong forced response. When mean state change is represented by the ensemble mean-capturing its spatial structure and temporal evolution-there is no significant forced change in PDV modes.Second, I assess solar radiation management (SRM) influence on ENSO. In idealized experiments, subtropical Pacific marine cloud brightening (MCB) reduces ENSO variance by roughly two-thirds, whereas stratospheric aerosol injection has minimal effect. A mixed layer heat budget analysis links the ENSO suppression to a La Nina-like mean state: cloud induced shortwave reductions cool the southeastern Pacific, strengthen easterlies, steepen the zonal thermocline tilt, and weaken the Bjerknes feedback. Given ENSO's central role in global hydroclimate and ecosystems, such suppression carries substantial risks.Third, I quantify changes in global marine heatwaves (MHWs) intensity. By late century, increases in MHW intensity are dominated by mean SST warming, with internal variability playing a minor role. Motivated by recent "Blob" events, I then examine the Northeastern Pacific SST trend. Single-forcing ensembles indicate aerosol forcing dominated the SST trend before ~1980, greenhouse gases thereafter, and that the recent (2009-2025) abrupt warming is primarily an expression of internal variability rather than a direct consequence of recent Chinese aerosol reductions.Together, this work implies that accurate representation of the mean state is critical for credible assessments of climate variability and for robust model-observation evaluation.
■590 ▼aSchool code: 0035.
■650 4▼aClimate change
■650 4▼aAtmospheric sciences
■650 4▼aPhysical oceanography
■650 4▼aGeophysics
■653 ▼aAnthropogenic emissions
■653 ▼aAtmosphere-ocean interaction
■653 ▼aClimate dynamics
■653 ▼aClimate modeling
■653 ▼aClimate variability
■653 ▼aMarine heatwaves
■690 ▼a0404
■690 ▼a0725
■690 ▼a0415
■690 ▼a0373
■71020▼aUniversity of California, Santa Barbara▼bEnvironmental Science & Management.
■7730 ▼tDissertations Abstracts International▼g87-04B.
■790 ▼a0035
■791 ▼aPh.D.
■792 ▼a2025
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17359638▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
