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Data-driven detection of waves in Earth's core and geophysical interpretation

数据驱动的地核波探测和地球物理解释

基本信息

批准号：
2214244
负责人：
Bruce Buffett
金额：
$ 17.23万
依托单位：
University of California-Berkeley
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2022
资助国家：
美国
起止时间：
2022-07-01 至 2024-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2214244&HistoricalAwards=false
关键词：
Data driven detection waves Earth

项目摘要

Earth’s magnetic field is an important element of the Earth system because it contributes to the habitability of our planet. Its existence protects the surface environment from charged particles that stream from the Sun. However, the origins of the magnetic field lie deep inside the liquid metal core, where it is continually generated by turbulent fluid motions. Many aspects of this generation process are poorly understood. Vast quantities of data from recent satellite missions create new opportunities to probe the generation process. The goal of this project is to combine modern methods in Data Science with the recent satellite observations to detect waves in the liquid metal core. These waves contribute to time variations in the magnetic field and provide broader insights into the underlying dynamics. These insights inform our understanding of the generation process, which enables predictions of changes in the magnetic field (much like weather forecasts). The objective is to assess changes in the protection of our surface environment, which benefits society. The project also supports fundamental research into the Earth system and supports the education of underrepresented groups in STEM disciplines.Satellite observations have substantially improved the quality of information that can be recovered from the magnetic field. Reliable estimates for the second time-derivative (known as secular acceleration) have become feasible in the past few years, and these records are well suited for detecting waves at the top of the core. This study uses a method known as dynamic mode decomposition to extract waves from huge volumes of satellite data. Detection of waves, and the recovery of the wave speeds, provides unique information about conditions at the top of the core. Many of the candidate waves depend on stratification at the top of the core, so detection of waves can offer strong constraints on the strength of stratification. Ultimately these questions are related to the geological evolution of the core and Earth as a whole. Factors such as the vigor of mantle convection or the extent of chemical interactions contribute to conditions at the core-mantle boundary. While useful records of secular acceleration are necessarily restricted to the satellite era (last twenty years), the duration of observed fluctuations means that the available record is now sufficient to extract novel insights into the dynamics of our planet.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.

地球磁场是地球系统的一个重要元素，因为它有助于我们星球的宜居性。它的存在保护了表面环境不受来自太阳的带电粒子的影响。然而，磁场的起源位于液态金属核心的深处，在那里它是由湍流运动不断产生的。这一生成过程的许多方面都没有得到很好的理解。从最近的卫星任务中获得的大量数据为探索产生过程创造了新的机会。该项目的目标是将数据科学的现代方法与最近的卫星观测相结合，以探测液态金属核心中的波。这些波有助于磁场的时间变化，并为潜在的动力学提供更广泛的见解。这些见解使我们了解了产生过程，从而能够预测磁场的变化（很像天气预报）。目的是评估在保护我们的地表环境方面的变化，这有利于社会。该项目还支持对地球系统的基础研究，并支持STEM学科中代表性不足群体的教育。卫星观测大大提高了可以从磁场中恢复的信息的质量。在过去的几年中，对二次导数（即长期加速度）的可靠估计已经变得可行，这些记录非常适合探测地核顶部的波。这项研究使用一种称为动态模态分解的方法从大量卫星数据中提取波。波的探测和波速的恢复，提供了关于堆芯顶部情况的独特信息。许多候选波依赖于核心顶部的分层，因此波的检测可以对分层的强度提供强有力的约束。最终，这些问题都与地核和整个地球的地质演化有关。地幔对流的活力或化学相互作用的程度等因素有助于形成核幔边界的条件。虽然长期加速的有用记录必然局限于卫星时代（最近二十年），但观测到的波动持续时间意味着，现有的记录现在足以对我们星球的动力学得出新的见解。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。