NSFGEO-NERC: Large-Scale Atmospheric Circulation Response to Oyashio Extension Frontal Variability

NSFGEO-NERC：大规模大气环流对 Oyashio 扩展锋面变化的响应

• 批准号: 2040073
• 负责人: Young-Oh Kwon
• 金额: $ 86.03万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2040073&HistoricalAwards=false
• 关键词: NSFGEO; NERC; Large; Scale; Atmospheric

Winter over the North Pacific features an endless parade of frontal storms, forming near Japan and building as they cross the ocean to reach North America. Model simulations can produce realistic North Pacific storms even if the sea surface temperatures (SSTs) are held fixed, indicating that the storms owe their existence to the strong upper-level jet stream and accompanying north-south atmopsheric temperature contrast rather than air-sea interactions. Nevertheless there are intriguing hints that storm behavior can be influenced by variations in the underlying SSTs, and some indications that slowly varying SSTs may change storm paths and behavior in ways that could prove useful for making long-range weather predictions. The SST variations of interest occur as a result of the meandering of the Kuroshio-Oyashio Extension (KOE), a narrow ocean current that extends into the Pacific from the coast of Japan. The KOE is a warm current and the sharp temperature contrast between the current and the cold water north of it produces relatively strong SST variations when the KOE shifts to the north or south.Attempts to identify and analyze the influence of KOE-related SST variations on storms and atmospheric circulation have had mixed results. But recent work by the Principal Investigators (PIs) and others suggests that the key to capturing the atmospheric response is to dramatically increase the resolution of atmospheric models used for this purpose. In particular the PIs have developed a variable resolution version of the Community Atmosphere Model version 6 (VR-CAM6) which takes advantage of the spectral element dynamical core to increase resolution over the North Pacific (a box from 20N to 60N and 130E to 110W). The lower resolution outside the North Pacific allows the model to be run cheaply enough to allow large ensembles of simulations, with 60 or more separate simulations for each imposed SST anomaly pattern, so that even weak atmospheric responses can be captured and analyzed.A further asset in identifying the atmospheric response to KOE-related SST variations is a simplified ocean model which allows the near-surface ocean to respond to changes in surface winds and other atmospheric forcing. The model is referred to as a "pencil" ocean model, or PenOM, because it represents the up and down transfer of heat in a column of the ocean below each grid box of the surface atmosphere. PenOM does not simulate the lateral movement of water in ocean currents, but work under this award adds the capability to represent changes in SST due to Ekman transport, meaning the sideways drift caused by the Coriolis force acting on water pushed along by the surface wind.The work is of societal as well as scientific interest due to its relevance to long-term weather prediction as noted above. Also, the PenOM configuration with Ekman transport will be made available to the worldwide research community through the Community Earth System Model as part of its suite of simpler model configurations. The work promotes international collaboration in atmospheric research through its collaboration with Dr. Arnaud Czaja at Imperial College London, through the arrangement noted below. Also, the project supports several outreach activities including the production of a short educational video featuring model simulations and research results. The project also provides support and training to a postdoctoral research associate.This project is jointly funded by the National Science Foundation’s Directorate of Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. The Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award, each Agency funds the proportion of the budget and the investigators associated with its own country.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

北太平洋的冬季会出现无尽的锋面风暴，这些风暴在日本附近形成，并在穿越海洋到达北美时产生，即使海面温度 (SST) 保持不变，模型模拟也可以模拟北太平洋风暴。风暴的存在归因于强烈的高空急流和伴随的南北大气温度对比，而不是海气相互作用。然而，有一些有趣的迹象表明，风暴行为可能受到底层海表温度变化的影响。有迹象表明，缓慢变化的海表温度可能会改变风暴路径和行为，这对进行长期天气预报是有用的。感兴趣的海表温度变化是由于黑潮-亲潮延伸部分（KOE）（一个狭窄的海洋）的蜿蜒而发生的。从日本海岸延伸到太平洋的KOE洋流是暖流，当KOE向北或向南移动时，该洋流与北部冷水之间的强烈温差会产生相对较强的海温变化。识别和分析与 KOE 相关的海温变化对风暴和大气环流的影响的结果好坏参半，但首席研究员 (PI) 和其他人最近的工作表明，捕获大气响应的关键是大幅提高分辨率。特别是用于此目的的大气模型，PI 开发了社区大气模型版本 6 (VR-CAM6) 的可变分辨率版本，它利用光谱元素动力核心来提高北太平洋的分辨率（20N 的盒子）。到60N 和 130E 至 110W），北太平洋以外的较低分辨率使得该模型的运行成本足够低，可以进行大型集合模拟，对每个强加的海表温度异常模式进行 60 次或更多单独的模拟，因此即使是微弱的大气响应也可以进行模拟。识别大气对 KOE 相关海温变化的响应的另一个资产是简化的海洋模型，该模型允许近地表海洋响应表面风和其他大气强迫的变化。被称为“铅笔”海洋模型（PenOM），因为它代表了表面大气每个网格盒下方海洋柱中的热量的上下传递，PenOM 并不模拟洋流中水的横向运动。 ，但该奖项下的工作增加了表示由于埃克曼输运而导致的海表温度变化的能力，这意味着科里奥利力作用于表面风推动的水面所引起的侧向漂移。这项工作具有社会和科学意义，因为其与长期的相关性如上所述，PenOM 配置与 Ekman 传输将通过社区地球系统模型提供给全球研究界，作为其更简单的模型配置套件的一部分。这项工作通过其合作促进了大气研究方面的国际合作。与伦敦帝国理工学院的 Arnaud Czaja 博士合作，通过下述安排，该项目还支持多项外展活动，包括制作展示模型模拟和研究成果的教育短片。该项目还为博士后研究提供支持和培训。该项目是联合该协议由美国国家科学基金会地球科学理事会 (NSF/GEO) 和英国国家环境研究委员会 (NERC) 通过 NSF/GEO-NERC 牵头机构协议资助。提案将由其研究人员在预算中所占比例最大的机构提交并进行同行评审。在成功联合确定奖项后，每个机构将资助与其本国相关的预算比例和研究人员。该奖项反映了 NSF 的情况。法定使命并具有通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

On the Statistical Estimation of Asymmetrical Relationship Between Two Climate Variables

• DOI: 10.1029/2022gl100777
• 发表时间: 2022-10-28
• 期刊: GEOPHYSICAL RESEARCH LETTERS
• 影响因子: 5.2
• 作者: Frankignoul, Claude;Kwon, Young-Oh
• 通讯作者: Kwon, Young-Oh

Multidecadal Regime Shifts in North Pacific Subtropical Mode Water Formation in a Coupled Atmosphere‐Ocean‐Sea Ice Model

耦合大气-海洋-海冰模型中北太平洋副热带模式水形成的多年代际变化

• DOI: 10.1029/2022gl099406
• 发表时间: 2022
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Kim, Sang‐Yeob;Kwon, Young‐Oh;Park, Wonsun;Lee, Ho Jin
• 通讯作者: Lee, Ho Jin