Collaborative Research: Targeted resampling of deep polar ice cores using information theory

冰芯包含了地球气候历史的详细记录。收集冰芯在后勤上具有挑战性，从冰芯中提取数据既耗时又容易受到人为和机器错误的影响。此外，冰芯测量数据中所包含的信息，科学家们还没有找到恢复的方法。这个项目将运用从信息论到冰芯数据的技术来解开这些信息。主要目标是证明信息理论可以(a)确定需要进一步分析的特定冰芯记录的区域，(b)为分析提供一些具体的指导。第二个目标是证明信息理论对过去气候的研究具有实际和科学的效用。该项目旨在以两种不同的方式使用信息论：首先，识别可能由于人为和/或机器错误而导致信息损坏或丢失的核心区域。例如，在南极西部冰原分裂核心的5000-8000年前的部分，信息理论方法揭示了明显的噪音水平，可能是由于实验室仪器，以及原始数据中看不到的东西。这是一段特别重要的记录，因为它包含了有关气候变化和全新世开始的宝贵线索。有针对性地对这部分岩心进行重新采样，并使用更新的实验室设备进行重新分析，可以解决数据问题。信息理论对冰芯分析的第二种潜在帮助是从数据中提取气候信号，比如在冰芯形成期间在冰芯地点的积累速率。这个数量通常需要大量的时间和精力来产生，但信息理论可以帮助简化这一过程。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。

Ice cores contain detailed accounts of Earth's climate history. The collection of an ice core can be logistically challenging, and extraction of data from the core can be time-consuming as well as susceptible to both human and machine error. Furthermore, locked in measurements from ice cores is information that scientists have not yet found ways to recover. This project will apply techniques from information theory to ice-core data to unlock that information. The primary goal is to demonstrate that information theory can (a) identify regions of a specific ice-core record that are in need of further analysis and (b) provide some specific guidance for that analysis. A secondary goal is to demonstrate that information theory has practical and scientific utility for studies of past climate. This project aims to use information theory in two distinct ways: first, to identify regions of a core where information appears to be damaged or missing, perhaps due to human and/or machine error. In the segment of the West Antarctic Ice Sheet Divide core that is 5000-8000 years old, for instance, information-theoretic methods reveal significant levels of noise, probably due to a laboratory instrument, and something that was not visible in the raw data. This is a particularly important segment of the record, as it contains valuable clues about climatic shifts and the onset of the Holocene. Targeted re-sampling of this segment of the core and reanalysis with newer laboratory apparatus could resolve the data issues. The second way in which information theory can potentially aid in ice-core analysis is by extracting climate signals from the data--such as the accumulation rate at the core site over the period of its formation. This quantity usually requires significant time and effort to produce, but information theory could help to streamline that process.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.