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Assessing the Role of Parameterized Turbulence on Tropical Cyclones and the Mean Climate in the Community Earth System Model
Assessing the Role of Parameterized Turbulence on Tropical Cyclones and the Mean Climate in the Community Earth System Model
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20260202104731
- ISBN
- 9798290648002
- DDC
- 536.7
- 저자명
- Nardi, Kyle M.
- 서명/저자
- Assessing the Role of Parameterized Turbulence on Tropical Cyclones and the Mean Climate in the Community Earth System Model
- 발행사항
- [Sl] : The Pennsylvania State University, 2025
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2025
- 형태사항
- 215 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 87-04, Section: B.
- 주기사항
- Advisor: Zarzycki, Colin.
- 학위논문주기
- Thesis (Ph.D.)--The Pennsylvania State University, 2025.
- 초록/해제
- 요약Earth System Models (ESMs) simulate the interaction of various components of the global Earth system. This includes, but is not limited to, atmospheric, oceanic, land, and sea ice processes. With enhanced computational capacity, we can now run ESMs at finer horizontal and vertical resolutions. However, despite these advances, many ESMs are incapable of resolving certain small-scale processes like boundary layer (PBL) turbulence. Therefore, these processes need to be estimated, or parameterized, based on theoretical or observed relationships with resolved fields. Prior studies have demonstrated that the choice of PBL parameterization is a key source of uncertainty in models of various spatial scales. In this study, we seek to understand how the parameterization of PBL turbulence, specifically the depiction of momentum fluxes, affects ESM model output.To answer this question, we use the Community Atmosphere Model version 6 (CAM6), the atmospheric component of the Community Earth System Model version 2 (CESM2). Turbulence in CAM6 is parameterized by the Cloud Layers Unified by Binormals (CLUBB) scheme. We adopt an experimental version of CLUBB (CLUBBX) with two key modifications: 1) a prognostic formulation of vertical momentum flux and 2) a regime-specific formulation for the dissipation of turbulent eddies. We perform a computationally-efficient sensitivity analysis (the Morris One-at-a-Time method) to identify a group of tunable CLUBBX parameters that appreciably impact CESM2-CAM6 output.In Chapter 3, we use MOAT to identify input parameters that affect the PBL structure of tropical cyclones (TCs) in an idealized 0.25° configuration of CAM6-CLUBBX. We highlight a handful of input parameters that broadly affect TC PBL structure, including metrics such as height of maximum tangential wind and latent heat flux fraction. In Chapter 4, we extend the MOAT analysis to 3-day, initialized global CAM6-CLUBBX simulations at 1° horizontal resolution. We find that the parameters appreciably impacting idealized TCs are also influential for key characteristics of the global mean climate, including cloud-radiative effects and surface wind stress. These influential parameters are physically linked to the modulation of vertical turbulent mixing in the PBL. Using parameter sensitivities from the 3-day simulations, we make targeted parameter perturbations to a longer (20-year) simulation. We find that for certain dynamical outputs, long simulations allow time for nonlinear feedbacks within the climate system to affect parameter sensitivities. In Chapter 5, we explore these nonlinear feedbacks and analyze the response of the general circulation to countergradient momentum fluxes in CLUBB. We show that reducing eddy diffusivity in the PBL contracts the Hadley cell and affects related precipitation patterns over the tropics.
- 일반주제명
- Heat
- 일반주제명
- Precipitation
- 일반주제명
- Humidity
- 일반주제명
- Wind shear
- 일반주제명
- Climate change
- 일반주제명
- Meteorology
- 일반주제명
- Atmospheric sciences
- 기본자료저록
- Dissertations Abstracts International. 87-04B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■007cr#unu||||||||
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■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a536.7
■1001 ▼aNardi, Kyle M.
■24510▼aAssessing the Role of Parameterized Turbulence on Tropical Cyclones and the Mean Climate in the Community Earth System Model
■260 ▼a[Sl]▼bThe Pennsylvania State University▼c2025
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2025
■300 ▼a215 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 87-04, Section: B.
■500 ▼aAdvisor: Zarzycki, Colin.
■5021 ▼aThesis (Ph.D.)--The Pennsylvania State University, 2025.
■520 ▼aEarth System Models (ESMs) simulate the interaction of various components of the global Earth system. This includes, but is not limited to, atmospheric, oceanic, land, and sea ice processes. With enhanced computational capacity, we can now run ESMs at finer horizontal and vertical resolutions. However, despite these advances, many ESMs are incapable of resolving certain small-scale processes like boundary layer (PBL) turbulence. Therefore, these processes need to be estimated, or parameterized, based on theoretical or observed relationships with resolved fields. Prior studies have demonstrated that the choice of PBL parameterization is a key source of uncertainty in models of various spatial scales. In this study, we seek to understand how the parameterization of PBL turbulence, specifically the depiction of momentum fluxes, affects ESM model output.To answer this question, we use the Community Atmosphere Model version 6 (CAM6), the atmospheric component of the Community Earth System Model version 2 (CESM2). Turbulence in CAM6 is parameterized by the Cloud Layers Unified by Binormals (CLUBB) scheme. We adopt an experimental version of CLUBB (CLUBBX) with two key modifications: 1) a prognostic formulation of vertical momentum flux and 2) a regime-specific formulation for the dissipation of turbulent eddies. We perform a computationally-efficient sensitivity analysis (the Morris One-at-a-Time method) to identify a group of tunable CLUBBX parameters that appreciably impact CESM2-CAM6 output.In Chapter 3, we use MOAT to identify input parameters that affect the PBL structure of tropical cyclones (TCs) in an idealized 0.25° configuration of CAM6-CLUBBX. We highlight a handful of input parameters that broadly affect TC PBL structure, including metrics such as height of maximum tangential wind and latent heat flux fraction. In Chapter 4, we extend the MOAT analysis to 3-day, initialized global CAM6-CLUBBX simulations at 1° horizontal resolution. We find that the parameters appreciably impacting idealized TCs are also influential for key characteristics of the global mean climate, including cloud-radiative effects and surface wind stress. These influential parameters are physically linked to the modulation of vertical turbulent mixing in the PBL. Using parameter sensitivities from the 3-day simulations, we make targeted parameter perturbations to a longer (20-year) simulation. We find that for certain dynamical outputs, long simulations allow time for nonlinear feedbacks within the climate system to affect parameter sensitivities. In Chapter 5, we explore these nonlinear feedbacks and analyze the response of the general circulation to countergradient momentum fluxes in CLUBB. We show that reducing eddy diffusivity in the PBL contracts the Hadley cell and affects related precipitation patterns over the tropics.
■590 ▼aSchool code: 0176.
■650 4▼aHeat
■650 4▼aPrecipitation
■650 4▼aHumidity
■650 4▼aWind shear
■650 4▼aClimate change
■650 4▼aMeteorology
■650 4▼aAtmospheric sciences
■690 ▼a0404
■690 ▼a0557
■690 ▼a0725
■71020▼aThe Pennsylvania State University.
■7730 ▼tDissertations Abstracts International▼g87-04B.
■790 ▼a0176
■791 ▼aPh.D.
■792 ▼a2025
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17358646▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.


