Global Atmospheric Modeling Hierarchy Development

全球大气模拟层次结构开发

• 批准号: 1733818
• 负责人: Isaac Held
• 金额: $ 36.82万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1733818&HistoricalAwards=false
• 关键词: Global; Atmospheric; Modeling; Hierarchy; Development

This project seeks to advance understanding in theoretical climate dynamics through the development and use of idealized models of varying levels of complexity. The models are designed to be only as complex as necessary to capture the phenomena of interest, which are assumed to be manifestations of fundamental climate system processes. One such model is the Held-Suarez model (HS, named for its creators), which does not include clouds or moist processes and uses thermal relaxation to generate the temperature contrast between the equator and the poles. Despite its simplicity the model reproduces many features of the atmospheric circulation including jet streams, reasonable approximations of middle-latitude weather systems, and the tropical overturning circulations known as Hadley cells.One use of the HS model is to test the hypothesis that key aspects of the atmospheric circulation, including the vigor of kinetic energy generation and the amount of heat transported from warmer to colder latitudes, can be understood in terms of Maximum Entropy Production (MEP). MEP can be used to derive an upper bound on kinetic energy generation in the HS model, but the upper bound is too large to be useful unless constraints are imposed which make it dependent on planetary rotation rate and other fundamental parameters. Research conducted here attempts to identify the appropriate constraints in the HS model and assess their relevance for more sophisticated models and the observed atmosphere. Other problems to be addressed include the role of lower tropospheric wave momentum fluxes in stormtrack dynamics, wave instabilities that transport westerly momentum from the middle latitudes into the tropics, and generation mechanisms for external Rossby waves.Additional problems are addressed with the HS model by incorporating a simplified representation of the hydrological cycle in which water vapor is treated as a passive tracer without radiative effects. Surface evaporation proceeds according to a standard bulk formula and water vapor condenses when it saturates at higher and colder altitudes. But the condensation does not result in clouds or latent heating and water cycling has no effect on atmospheric circulation. Despite these omissions the model produces water vapor streamers, frontal precipitation patterns, and atmospheric rivers which resemble their real-world counterparts. The model is used here to study kinematic constraints on the mean strength of the hydrological cycle and its response over continents to warmer conditions. For the latter application continents are specified using a simplified "bucket" representation of soil moisture.Further research is conducted with a model at a somewhat higher level of complexity, which uses simplified atmospheric radiative transfer (the grey-body approximation) rather than thermal relaxation to produce the pole-to-equator temperature contrast. The model allows the hydrological cycle to affect circulation through condensational heating, but water vapor has no effect on radiative transfer and clouds are not represented. This version of the model is used to study the behavior of the intertropical convergence zone (ITCZ), the narrow band of clouds and precipitation usually found near the equator. One strategy is to modify the model so that it represents only a limited zonal sector of the atmosphere, so that disturbances of the ITCZ caused by phenomena larger than the width of the sector are eliminated.The work has scientific broader impacts through the sharing of model codes and documentation with the research community through a web portal. Versions of the models have already gained broad acceptance as research tools, but they have been disseminated largely through personal connections with the PIs' research group. Beyond their value for isolating and examining specific climate system processes, the models have proven useful for testing numerical methods used in comprehensive climate models. In addition, the models can play an important role in communicating climate science to the public and researchers in other scientific fields. Simple models are valuable for this purpose as they can be used to demonstrate that the simplifications required for effective communication correctly represent, albeit in approximate form, the workings of the climate system. The project also provides support and training for a graduate student, thereby providing for workforce development in this research area.

该项目旨在通过开发和使用不同级别的复杂程度的理想化模型来提高理论气候动态的理解。 这些模型的设计仅是必要的复杂，以捕获感兴趣的现象，这些现象被认为是基本气候系统过程的表现。 一个这样的模型是Held-Suarez模型（HS，以其创造者的名字命名），该模型不包括云或潮湿的过程，并使用热松弛来产生赤道和杆之间的温度对比。 尽管它很简单，但该模型还是重现了大气循环的许多特征，包括喷气流，中纬度天气系统的合理近似值以及热带倾覆的循环被称为哈德利细胞。一种使用HS模型是测试假设的假说，即在大气循环中的关键方面，包括对Kinetic Entry of Kinety of Colder of Colder的量的最大程度的循环，该循环量的最大程度，以及较高的热量范围，而colder countery of Colder of Colder of Coldery coilder of Coldery countery coilder of Coldery countery coilder coilder coilder coilder coilder coilder的量很高，却是colder的量。 （MEP）。 MEP可用于在HS模型中导致动力学产生的上限，但是上界太​​大，除非施加约束，从而依赖于行星旋转速率和其他基本参数。 这里进行的研究试图确定HS模型中适当的约束，并评估其与更复杂的模型和观察到的氛围的相关性。待解决的其他问题包括对流层波动动量磁通量在防暴动力学中的作用，将西风势从中间纬度传递到热带地区的波动不稳定性以及外部rossby波的产生机制。在不遵循水的效果的情况下，通过与HS的模型相结合，与HS一起解决了ADDICETAL问题。 表面蒸发根据标准散装配方和水蒸气在较高和较冷的高度饱和时进行凝结。 但是冷凝不会导致云或潜在的加热和水循环对大气循环没有影响。 尽管存在这些遗漏，但该模型仍会产生水蒸气流质，额叶降水模式和大气河流类似于其现实世界中的河流。 该模型在这里用于研究水文循环的平均强度及其在大陆对温暖条件的反应的基础限制。 对于后一种施用，使用简化的土壤水分的“桶”表示指定了大洲。Further研究是在更高水平的复杂性水平的模型中进行的，该模型使用简化的大气辐射转移（灰色体近似），而不是热弛豫，而不是产生极向备用温度对比。 该模型允许水文循环通过凝结加热影响循环，但是水蒸气对辐射转移没有影响，云没有代表。 该模型的此版本用于研究中受热物收敛区（ITCZ）的行为，云和降水通常在赤道附近发现。 一种策略是修改模型，以使其仅代表有限的大气区域，以便消除由大于该领域的现象引起的ITCZ的干扰。该工作通过通过Web Portal与研究社区共享模型代码和文档，从而产生了更广泛的影响。 这些模型的版本已经获得了作为研究工具的广泛接受，但是通过与PIS研究小组的个人联系，它们已被传播。 除了它们用于隔离和检查特定气候系统过程的价值之外，这些模型已被证明可用于测试在综合气候模型中使用的数值方法。 此外，这些模型可以在向其他科学领域的公众和研究人员传达气候科学方面发挥重要作用。 简单的模型对于此目的是有价值的，因为它们可以用来证明有效沟通所需的简化，尽管以近似形式，即气候系统的运作方式。 该项目还为研究生提供了支持和培训，从而为该研究领域提供了劳动力发展。

项目成果

The Parameter Dependence of Eddy Heat Flux in a Homogeneous Quasigeostrophic Two-Layer Model on a β Plane with Quadratic Friction

具有二次摩擦的 β 平面上均质准地转双层模型中涡流热通量的参数依赖性

• DOI: 10.1175/jas-d-20-0145.1
• 发表时间: 2021
• 期刊: Journal of the Atmospheric Sciences
• 影响因子: 3.1
• 作者: Chang, Chiung-Yin;Held, Isaac M.
• 通讯作者: Held, Isaac M.

Westward-Propagating Rossby Modes in Idealized GCMs

理想化 GCM 中向西传播的罗斯贝模态

• DOI: 10.1175/jas-d-20-0276.1
• 发表时间: 2021
• 期刊: Journal of the Atmospheric Sciences
• 影响因子: 3.1
• 作者: Zurita-Gotor, Pablo;Held, Isaac M.
• 通讯作者: Held, Isaac M.

Lower-Tropospheric Eddy Momentum Fluxes in Idealized Models and Reanalysis Data

理想化模型和再分析数据中的对流层低层涡动量通量

• DOI: 10.1175/jas-d-17-0099.1
• 发表时间: 2017
• 期刊: Journal of the Atmospheric Sciences
• 影响因子: 3.1
• 作者: Lutsko, Nicholas J.;Held, Isaac M.;Zurita-Gotor, Pablo;O’Rourke, Amanda K.
• 通讯作者: O’Rourke, Amanda K.

Modeling Water Vapor and Clouds as Passive Tracers in an Idealized GCM

在理想化的 GCM 中将水蒸气和云建模为被动示踪剂

• DOI: 10.1175/jcli-d-16-0812.1
• 发表时间: 2018
• 期刊: Journal of Climate
• 影响因子: 4.9
• 作者: Ming, Yi;Held, Isaac M.
• 通讯作者: Held, Isaac M.

Mechanism of Fast Atmospheric Energetic Equilibration Following Radiative Forcing by CO 2

CO 2 辐射强迫后的快速大气能量平衡机制

• DOI: 10.1002/2017ms001116
• 发表时间: 2017
• 期刊: Journal of Advances in Modeling Earth Systems
• 影响因子: 6.8
• 作者: Dinh, T.;Fueglistaler, S.
• 通讯作者: Fueglistaler, S.