P2C2: Tropical Pacific Influences on Atmospheric Blocking across Climates

大气阻塞事件是持续的天气模式，通常是高压系统，使中纬度急流和风暴转向数天至数周，并可能与热浪，寒流，干旱和洪水等极端天气有关。大气阻塞及其相关极端事件对人为气候变化的响应存在很大的不确定性，包括其频率、强度和持续时间，以及气候变率对它们的调节。厄尔尼诺-南方涛动（ENSO）事件期间热带太平洋的平均气候状态和异常影响大气阻塞;然而，这些影响因ENSO“风味”（东太平洋或中太平洋）而异。因此，阻塞预测的不确定性部分是由于热带太平洋平均状态和ENSO多样性及其潜在相互作用的预测变化的不确定性。该项目的目的是调查观测中厄尔尼诺/南方涛动多样性、大气阻塞和极端事件之间的关系以及现有和新的有针对性的模式实验。通过古气候模型-代用指标综合，该项目将有可能使偏差的评估和发展的限制，为未来预测大气阻塞和相关的极端天气，因为他们受到热带地区的影响。工作重点是系统和分层调查之间的关系，大气阻塞和相关的极端天气，将特别考虑不同国家的影响热带地区。太平洋平均气候和ENSO多样性。为此，研究人员将在多个时间尺度上将大气阻塞特征和极端事件频率与热带太平洋的状态联系起来（多年代际，年际），并通过综合GCM现在和过去气候试验的诊断分析，新的高分辨率（~ 15公里）模式试验，旨在隔离热带太平洋的作用，极端天气的统计建模和古气候代用记录。这项调查将提供新的见解，热带地区对中纬度极端事件的影响，并允许定量合成的古气候代理和模型，以评估模型的技能，代表这些关系。最终的目标是设计指标，减少模型的不确定性，在模拟外部强迫的变化阻塞，换句话说，计算阻塞预测的基础上，热带太平洋平均状态和多样性的模拟技巧的限制。潜在的更广泛的影响包括一个综合、验证和解释过去气候和现代观测的综合框架，以评估区域和全球尺度的未来气候预测。该项目有可能改善极端天气的预测和与气候变化和变率、大气阻塞和极端事件交叉相关的风险评估，并开发越来越多地被学术机构、政府机构和私营部门&研发公司（包括保险公司、银行、该研究将为研究生和本科生提供关于天气和气候风险分析新技术的科学培训，该培训将在标题III -亚裔美国人和美洲土著太平洋岛民服务机构（AANAPI）中进行。此外，还将开发一个新的在线外联模块，以纳入两年一度的索斯特开放日活动，供K-12游客和公众参加（约10分钟的活动），旨在提高对ENSO风味独特影响的认识和理解。 这个新模块将被设计为ENSO影响游戏，玩家将放置一个对应于不同ENSO口味的海面温度异常，这将改变板上急流的位置。然后，他们将被要求猜测ENSO在多个地点的影响，包括夏威夷（湿/干，暖/冷），因为它们与急流的变化有关，并将根据命中和未命中分配分数。该模块将公开分享给全国各地的教育工作者使用。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

Atmospheric blocking events are persistent weather patterns, most often high-pressure systems, that divert the mid-latitude jet stream and storms for days to weeks and can be associated with extreme weather such as heat waves, cold spells, droughts, and flooding. There is significant uncertainty surrounding the response of atmospheric blocking and its related extreme events to anthropogenic climate change, including their frequency, intensity, and duration, as well as their modulation by climate variability. The mean climate state and anomalies of the tropical Pacific during El Niño-Southern Oscillation (ENSO) events influence atmospheric blocking; however, these impacts vary depending on the ENSO “flavor” (Eastern or Central Pacific). Thus, part of the uncertainty in blocking projections is due to uncertainties in the projected changes in both the tropical Pacific mean state and ENSO diversity and their potential interactions. This project aims to investigate the relationship between ENSO diversity, atmospheric blocking and extreme events in observations and existing and new targeted model experiments. Via a paleoclimate model-proxy synthesis, the project will potentially enable the assessment of biases and the development of constraints for future projections of atmospheric blocking and associated weather extremes as they are influenced by the tropics.The work focuses on a systematic and hierarchical investigation of the relationship between atmospheric blocking and associated weather extremes that will specifically consider the impact of different states of tropical Pacific mean climate and of ENSO diversity. To this end, the researchers will relate atmospheric blocking characteristics and extreme event frequency to the state of the tropical Pacific at multiple time scales (multidecadal, interannual) and, diagnose the underlying mechanisms via a synthesis of diagnostic analysis of GCM present-day and past climate experiments, new high-resolution (~15km) model experiments designed to isolate the role of the tropical Pacific, statistical modeling of weather extremes, and paleoclimate proxy records. This investigation will offer new insights into the impact of the tropics on midlatitude extreme events and allow for a quantitative synthesis of paleoclimate proxies and models to assess model skill in representing these relationships. The ultimate goal is to devise metrics that reduce model uncertainty in simulations of externally-forced changes in blocking, in other words calculate constraints for blocking projections based on simulation skill of tropical Pacific mean state and diversity. The potential broader impacts include a comprehensive framework for integration, validation and interpretation of past climate and modern observations to evaluate future climate projections at regional and global scales. This project has the potential to improve the prediction of extreme weather and assessment of risk associated with the intersection of climate change and variability, atmospheric blocking, and extreme events, and develops knowledge and resources that are increasingly being used by academic institutions, government agencies, and private-sector R&D companies, including insurance companies, banks, and consulting firms.The research will provide scientific training for graduate and undergraduate students on new technologies on weather and climate risk analysis in Title III - Asian American and Native American Pacific Islander-Serving Institutions (AANAPI). Additionally, a new online outreach module will be developed to be incorporated in the biennial SOEST Open House Activities for K-12 visitors and the general public (~10-minute activities), designed to raise awareness and understanding of the distinct impacts of ENSO flavors. This new module will be designed as an ENSO impacts game, where the players will place a Sea Surface Temperature anomaly corresponding to different ENSO flavors, which will change the position of the jet stream on the board. They will then be asked to guess the ENSO impacts in multiple locations, including Hawaii (wet/dry, warm/cold) as they relate to changes in the jet stream, and will be assigned scores based on hits and misses. The module will be shared publicly to be used by educators across the 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.