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

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。研究过去暖期的西风带尤为重要，因为对天气模式的现代观测表明，西风正因全球变暖而向极地移动。这项拟议的研究将利用尘埃积累和上层海洋生物生产力的沉积物记录来记录北半球西风带的强度和位置。北太平洋的沉积物岩心覆盖了过去的15万年。它们将包括最近一次全球变暖间隔，大约在13万到11.5万年前。拟议研究的更广泛影响包括支持一名博士后。该研究还将通过拉蒙特高中实习计划为高中生提供实践研究的机会。该项目建立在与纽约市和罗克兰县高中现有伙伴关系的基础上，从地球科学领域代表性不足的群体中招收学生。本研究将利用来自北太平洋的5 ~150 kyr粉尘、生产力和粒度记录来表征不同平均气候状态（MIS 5e和全新世的间冰期高峰以及MIS 6和末次盛冰期高峰）的西风，以及它们如何响应终止期I和II的突变气候变化。这些记录将使用最近的RV Sonne研究巡航到北太平洋（SO264）的5个海洋沉积物岩心样本，这些样本包括~15°纬度。这些数据将填补北半球一个关键地区目前情况的空白，并将作为模拟研究的基准。这些数据集对古气候和现代/未来气候模拟领域都很有用，因为它们将提供西风带自然变率对潜在驱动机制（如冰量和大气温度梯度）变化的约束，从而有助于西风未来变化的基本模拟。最后，这项工作的结果可以作为在世界其他地区（如南半球）进行类似研究的推动力，从而解决与不同气候制度下大气环流半球同步性有关的问题。PI是新的拉蒙特LDEI特别工作组的联合主席，并深入参与实施各个层面的多样性项目，包括积极招募地球科学领域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年度Lamont-Doherty开放日等非技术设置向公众展示。该奖项反映了美国国家科学基金会的法定使命，并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，被认为值得支持。

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.