Perspective on ice age Terminations from absolute chronologies provided by global speleothem records

IF 3.8 2区地球科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY

Climate of The Past Pub Date : 2024-05-23 DOI:10.5194/cp-2024-37

Nikita Kaushal, Carlos Perez-Mejias, Heather M. Stoll

{"title":"Perspective on ice age Terminations from absolute chronologies provided by global speleothem records","authors":"Nikita Kaushal, Carlos Perez-Mejias, Heather M. Stoll","doi":"10.5194/cp-2024-37","DOIUrl":null,"url":null,"abstract":"<strong>Abstract.</strong> Glacial Terminations represent the largest amplitude climate changes of the last several million years. Several possible orbital-insolation triggers have been described to initiate and sustain glacial Terminations. Because of the availability of radiocarbon dating, the most recent Termination (TI) has been extensively characterized. Yet, it is widely discussed whether the sequence of feedbacks, millennial events and rates of change seen in TI is recurrent over previous Terminations. Beyond the limit of radiocarbon dating, records from the speleothem archive provide absolute age control through uranium-thorium dating and high-resolution proxy measurements. The PAGES SISALv3 global speleothem database allows us to synthesize the available speleothem records covering Terminations. However, speleothem climate signals are encoded in a number of proxies, and unlike proxies in other archives like ice or marine cores, the climatic interpretation of a given proxy can vary quite significantly among different regions. In this study, we <ul> <li>synthesize the available speleothem records providing climate information for Terminations: TII, TIIIA,TIII, TIV and TV,</li> <li>present the records based on the aspect of climate encoded in the available records,</li> <li>examine the effects of different ice volume corrections on the final climate proxy record,</li> <li>evaluate whether there are leads and lags in the manifestation of Terminations across different aspects of the climate systems and different regions,</li> <li>we suggest directions for future speleothem research covering Terminations, speculate on suitable tuning targets among marine and ice core proxies, and discuss what model outputs maybe most suitable for comparison.</li> </ul> We find that TII has the greatest number of globally distributed records followed by TIIA and TIII. The records covering TIV and TV are largely restricted to the East Asian and Southeast Asian monsoon regions. Modelling and data-model comparison studies have greatly increased our understanding of the interpretation of oxygen isotope records across Terminations. Ice volume corrections have the most significant impact on European speleothem records with moisture sourced directly from the North Atlantic region. Within each Termination, a sequence of events can be established between a sub-set of events and this sequence stays largely consistent across Terminations. However, improvements in dating and age-model uncertainties, higher resolution records and multi-proxy approaches are required to establish sequences within each sub-set of events. Beyond further research on targeted speleothem records, our recommendations for future directions include focusing on TII as a useful next target to understand climate dynamics, isotope-enabled transient simulations for better characterization of the other Terminations, and development of marine proxy records with signals common to speleothems to further improve the chronology of Terminations.","PeriodicalId":10332,"journal":{"name":"Climate of The Past","volume":"46 1","pages":""},"PeriodicalIF":3.8000,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Climate of The Past","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.5194/cp-2024-37","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}

引用次数: 0

Abstract

Abstract. Glacial Terminations represent the largest amplitude climate changes of the last several million years. Several possible orbital-insolation triggers have been described to initiate and sustain glacial Terminations. Because of the availability of radiocarbon dating, the most recent Termination (TI) has been extensively characterized. Yet, it is widely discussed whether the sequence of feedbacks, millennial events and rates of change seen in TI is recurrent over previous Terminations. Beyond the limit of radiocarbon dating, records from the speleothem archive provide absolute age control through uranium-thorium dating and high-resolution proxy measurements. The PAGES SISALv3 global speleothem database allows us to synthesize the available speleothem records covering Terminations. However, speleothem climate signals are encoded in a number of proxies, and unlike proxies in other archives like ice or marine cores, the climatic interpretation of a given proxy can vary quite significantly among different regions. In this study, we

synthesize the available speleothem records providing climate information for Terminations: TII, TIIIA,TIII, TIV and TV,
present the records based on the aspect of climate encoded in the available records,
examine the effects of different ice volume corrections on the final climate proxy record,
evaluate whether there are leads and lags in the manifestation of Terminations across different aspects of the climate systems and different regions,
we suggest directions for future speleothem research covering Terminations, speculate on suitable tuning targets among marine and ice core proxies, and discuss what model outputs maybe most suitable for comparison.

We find that TII has the greatest number of globally distributed records followed by TIIA and TIII. The records covering TIV and TV are largely restricted to the East Asian and Southeast Asian monsoon regions. Modelling and data-model comparison studies have greatly increased our understanding of the interpretation of oxygen isotope records across Terminations. Ice volume corrections have the most significant impact on European speleothem records with moisture sourced directly from the North Atlantic region. Within each Termination, a sequence of events can be established between a sub-set of events and this sequence stays largely consistent across Terminations. However, improvements in dating and age-model uncertainties, higher resolution records and multi-proxy approaches are required to establish sequences within each sub-set of events. Beyond further research on targeted speleothem records, our recommendations for future directions include focusing on TII as a useful next target to understand climate dynamics, isotope-enabled transient simulations for better characterization of the other Terminations, and development of marine proxy records with signals common to speleothems to further improve the chronology of Terminations.

查看原文本刊更多论文

从全球岩浆记录提供的绝对年代学透视冰期的终结

摘要冰川终结代表了过去几百万年中幅度最大的气候变化。已经描述了几种可能的轨道-日照触发因素来启动和维持冰川终结。由于可以进行放射性碳年代测定，最近的冰川终结（TI）已被广泛描述。然而，人们广泛讨论的是，在 TI 中看到的一系列反馈、千年事件和变化率是否在以前的终结中反复出现。在放射性碳测年的限制之外，通过铀-钍测年和高分辨率代用测量，来自岩浆档案的记录提供了绝对的年龄控制。通过 PAGES SISALv3 全球岩浆数据库，我们可以综合涵盖终结期的现有岩浆记录。然而，岩浆气候信号是由许多代用指标编码的，与冰或海洋岩芯等其他档案中的代用指标不同，不同地区对特定代用指标的气候解释可能有很大差异。在这项研究中，我们综合了提供 "终结点 "气候信息的现有岩浆记录：TII、TIIIA、TIII、TIV 和 TV 记录，根据现有记录所编码的气候方面来介绍这些记录，研究不同冰量校正对最终气候代用记录的影响，评估气候系统不同方面和不同地区的终结现象是否存在领先和滞后现象，提出未来涉及终结现象的岩浆研究方向，推测海洋和冰芯代用指标中合适的调整目标，并讨论哪些模型输出可能最适合进行比较。我们发现 TII 有最多的全球分布记录，其次是 TIIA 和 TIII。涵盖 TIV 和 TV 的记录主要局限于东亚和东南亚季风区。建模和数据-模型对比研究大大提高了我们对各终端氧同位素记录解释的理解。冰量校正对欧洲岩浆记录的影响最大，其水分直接来自北大西洋地区。在每个终止点内，可以在一个子事件集之间建立一个事件序列，这个序列在各个终止点之间基本保持一致。然而，要在每个事件子集中确定序列，还需要改进年代测定和年龄模型的不确定性，提高记录的分辨率，并采用多代理方法。除了进一步研究有针对性的岩浆记录外，我们对未来方向的建议还包括：将 TII 作为了解气候动态的下一个有用目标；利用同位素进行瞬态模拟，以更好地描述其他终结点的特征；开发具有岩浆共同信号的海洋代用记录，以进一步改进终结点的年代学。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Climate of The Past 地学-气象与大气科学

CiteScore

7.40

自引率

14.00%

发文量

120

审稿时长

4-8 weeks

期刊介绍： Climate of the Past (CP) is a not-for-profit international scientific journal dedicated to the publication and discussion of research articles, short communications, and review papers on the climate history of the Earth. CP covers all temporal scales of climate change and variability, from geological time through to multidecadal studies of the last century. Studies focusing mainly on present and future climate are not within scope. The main subject areas are the following: reconstructions of past climate based on instrumental and historical data as well as proxy data from marine and terrestrial (including ice) archives; development and validation of new proxies, improvements of the precision and accuracy of proxy data; theoretical and empirical studies of processes in and feedback mechanisms between all climate system components in relation to past climate change on all space scales and timescales; simulation of past climate and model-based interpretation of palaeoclimate data for a better understanding of present and future climate variability and climate change.