Tracking the movement and strength of the Northern Hemisphere westerlies over the last glacial cycle.

追踪上一次冰期期间北半球西风的运动和强度。

• 批准号: 2103037
• 负责人: Gisela Winckler
• 金额: $ 29.78万
• 依托单位: Columbia University
• 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: 2021-07-15 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2103037&HistoricalAwards=false
• 关键词: Tracking; movement; strength; Northern; Hemisphere

The westerly wind belts are a key part of the climate system. Knowing the strength and position of the westerlies during different climate states and across abrupt shifts in climate would provide insight into the mechanisms of climate variability. Studying the westerlies during past warm intervals is particularly important because modern observations of weather patterns suggest that the westerly winds are moving poleward in response to global warming. The proposed study will document the strength and position of the Northern Hemisphere westerlies using sediment records of dust accumulation and upper ocean biological productivity. Sediment cores from sites in the North Pacific Ocean will cover the last 150,000 years. They will include the most recent global warm interval roughly 130,000 to 115,000 years ago. The Broader Impacts of the proposed study include support for a postdoctoral fellow. The study also will provide opportunities for including high school students in hands-on research through the Lamont High school Intern Program. That program builds on existing partnerships with New York City and Rockland County high schools to recruit students from groups underrepresented in the earth sciences. This proposed study will produce five ~150 kyr dust, productivity, and grain size records from the North Pacific Ocean to characterize the westerly winds during various mean climate states (peak interglacials of MIS 5e and the Holocene as well as peak glacials of MIS 6 and the last glacial maximum), and how they respond to abrupt climate changes during Terminations I and II. These records will use samples from five marine sediment cores from a recent RV Sonne research cruise to the North Pacific (SO264) that encompass ~15° latitude. These data will fill a gap in the current picture of a key region in the Northern Hemisphere and will serve as benchmarks for modeling studies. These datasets will be useful to both the paleoclimate and modern/future climate modeling fields, as they will provide constraints on the natural variability of the westerlies to changes in potential driving mechanisms such as ice volume and atmospheric temperature gradients, thus aiding essential modeling of future changes in the westerly winds. Finally, the results of this work could serve as the impetus to perform similar studies in other regions of the world, such as the Southern Hemisphere, allowing questions related to hemispheric synchroneity of atmospheric circulation across various climate regimes to be addressed. The PI is the co-chair of the new Lamont LDEI Task Force and is deeply involved in implementing diversity programs on all levels, including active recruitment of underrepresented minorities in the Geosciences. Interpretations and conclusions drawn from this work will be brought to the public via non-technical settings such as the annual Lamont-Doherty Open House.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.

西风带是气候系统的重要组成部分。了解西风带在不同气候状态和气候突变期间的强度和位置将有助于深入了解气候变率的机制。研究过去温暖时期的西风带尤为重要，因为现代天气模式的观测表明，西风正向极地移动，以应对全球变暖。拟议的研究将利用沉积物记录的灰尘积累和上层海洋生物生产力，记录北方半球西风的强度和位置。来自北太平洋各地点的沉积物岩心将涵盖过去15万年。它们将包括大约130，000至115，000年前最近的全球变暖间隔。拟议研究的更广泛影响包括对博士后研究员的支持。这项研究还将提供机会，包括高中学生在动手研究，通过拉蒙高中实习生计划。该项目建立在与纽约市和罗克兰县高中现有的合作关系基础上，从地球科学代表性不足的群体中招收学生。这项研究将产生5 ~150 kyr的灰尘，生产力和粒度记录从北太平洋的西风在不同的平均气候状态（峰值间冰期的MIS 5e和全新世，以及峰值冰川的MIS 6和末次盛冰期），以及它们如何响应终端I和II期间的气候突变。这些记录将使用最近RV索内号到北太平洋（SO 264）进行的一次研究航行中采集的五个海洋沉积物岩心样本，这些样本涵盖约15°纬度。这些数据将填补北方一个关键地区目前情况的空白，并将作为建模研究的基准。这些数据集将是有用的古气候和现代/未来的气候模拟领域，因为它们将提供约束西风带的自然变化的潜在驱动机制，如冰量和大气温度梯度的变化，从而帮助基本的模拟西风带的未来变化。最后，这项工作的结果可以作为在世界其他地区，如南半球进行类似研究的动力，从而解决与不同气候系统的大气环流半球同步性有关的问题。PI是新的拉蒙LDEI工作组的联合主席，并深入参与各级实施多样性计划，包括积极招募地球科学中代表性不足的少数民族。从这项工作中得出的解释和结论将通过非技术性的设置，如年度拉蒙特-多尔蒂开放日，向公众展示。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知识价值和更广泛的影响审查标准进行评估来支持。