Collaborative Research: Dynamical Mechanisms for Midlatitude-Arctic Interactions and Associated Weather Extremes in a Warming Climate

合作研究：气候变暖中中纬度-北极相互作用及相关极端天气的动力机制

• 批准号: 2232581
• 负责人: Gang Chen
• 金额: $ 70.77万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-15 至 2026-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2232581&HistoricalAwards=false
• 关键词: Collaborative; Research; Dynamical; Mechanisms; Midlatitude

Persistent weather systems in winter cause cold spells, heavy rainfall, or snow. These weather extremes are closely related to the location and intensity of midlatitude jet streams, which blow from west to east and often shift to the north and south. As Earth’s climate gets warmer, the jet streams are affected by the tug-of-war between the rapid surface warming over the Arctic and the enhanced upper-tropospheric warming in the tropics. The investigators will examine several interrelated dynamical mechanisms for midlatitude-Arctic interactions and the associated weather extremes. The first theme is the linkage between the planetary waves in the stratosphere and the risk of cold events. This task will test the hypothesis that extreme wave events in the stratospheric polar vortex serve as a source of intraseasonal predictability for cold events over North America. This linkage between the stratosphere and surface temperature will be analyzed in observations and climate models. Secondly, the investigators will examine a hypothesis that a weaker jet stream under rapid Arctic warming would lead to more frequent weather extremes in mid-latitudes. This task will perform idealized numerical simulations to examine the effect of jet speed or jet structure on the north and south shifts of a jet and thus attempt to reconcile different views on the changes in midlatitude circulation waviness in response to climate warming. The third task is on atmospheric rivers, the narrow intense moisture transport associated with midlatitude cyclones. Atmospheric rivers dominate the poleward moisture flux in the middle and high latitudes, which contribute to Arctic warming. Intense moisture transport can be influenced by either wind speed or temperature, and the two factors will be studied in an atmospheric transport model of water vapor and cloud tracers.Midlatitude weather extremes have profound socioeconomic impacts. Predictive skills from extreme stratospheric events could improve the sub-seasonal forecast of winter cold spells over North America, with important implications for energy consumption and transportation. A better understanding of extreme cold events in a warming climate can foster better communications of global warming science between the scientific community and the public. Improved predictions of the intense moisture transport by midlatitude cyclones into the Arctic help better adapt to the changing Arctic. Besides supporting an early career scientist at Penn State University, the proposal will train two graduate student researchers at UCLA in the analysis of observations and climate models. Several UCLA undergraduates will be trained in statistical analysis of climate data, particularly for STEM majors and underrepresented minorities. The idealized models developed in this study will be made available on a GitHub website with sample python scripts.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.

冬季持续的天气系统会导致寒潮、强降雨或降雪，这些极端天气与中纬度急流的位置和强度密切相关，中纬度急流从西向东吹，并且经常随着地球气候的变化而向北和南移动。随着气候变暖，急流受到北极地表快速变暖和热带地区上层对流层变暖加剧之间的拉锯战的影响。研究人员将研究中纬度地区与北极相互作用的几种相互关联的动力机制。第一个主题是平流层中的行星波与寒冷事件风险之间的联系这项任务将检验平流层极地涡旋中的极端波事件作为寒冷事件季节内可预测性来源的假设。北美：平流层与地表温度之间的这种联系将在观测和气候模型中进行分析，研究人员将检验一个假设，即北极快速变暖导致急流减弱将导致中纬度地区出现更频繁的极端天气。该任务将进行理想化的数值模拟，以研究急流速度或急流结构对急流南北移动的影响，从而尝试协调对中纬度环流波动响应气候变暖的变化的不同看法。在大气河流上，与中纬度气旋相关的狭窄的强烈水汽输送主导了中高纬度的向极地水汽通量，这导致北极变暖。强烈的水汽输送可能受到风速或温度的影响。将在水蒸气和云示踪剂的大气传输模型中研究两个因素。中纬度极端天气具有深远的经济影响，极端平流层事件的预测技能可以改善北美冬季寒流的次季节预报，对经济具有重要影响。更好地了解气候变暖中的极端寒冷事件可以促进科学界和公众之间更好地交流全球变暖科学，改进对中纬度气旋向北极输送的强烈水分的预测有助于更好地适应气候变化。改变除了支持宾夕法尼亚州立大学的一名早期职业科学家外，该提案还将培训加州大学洛杉矶分校的两名研究生研究人员进行观测和气候模型分析，一些加州大学洛杉矶分校的本科生将接受气候数据统计分析的培训，特别是 STEM 专业和气候数据统计分析。本研究中开发的理想化模型将在 GitHub 网站上提供，其中包含示例 Python 脚本。该奖项是 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查进行评估，被认为值得支持。标准。

项目成果

The role of interdecadal climate oscillations in driving Arctic atmospheric river trends

• DOI: 10.1038/s41467-024-45159-5
• 发表时间: 2024-03-08
• 期刊: Nature Communications
• 影响因子: 16.6
• 作者: Weiming Ma;Hailong Wang;Gang Chen;L. Leung;Jian Lu;P. J. Rasch;Qiang Fu;B. Kravitz;Yufei Zou;J. Cassano;W. Maslowski
• 通讯作者: W. Maslowski

Stratosphere‐Troposphere Coupling of Extreme Stratospheric Wave Activity in CMIP6 Models

平流层 — CMIP6 模型中极端平流层波活动的对流层耦合

• DOI: 10.1029/2023jd038811
• 发表时间: 2023-08
• 期刊: Journal of Geophysical Research: Atmospheres
• 作者: Ding, Xiuyuan;Chen, Gang;Ma, Weiming
• 通讯作者: Ma, Weiming

Extreme stratospheric wave activity as harbingers of cold events over North America

极端平流层波活动是北美寒冷事件的先兆

• DOI: 10.1038/s43247-023-00845-y
• 发表时间: 2023-05
• 期刊: Communications Earth & Environment
• 影响因子: 7.9
• 作者: Ding, Xiuyuan;Chen, Gang;Zhang, Pengfei;Domeisen, Daniela I. V.;Orbe, Clara
• 通讯作者: Orbe, Clara