田立军^1,2,,
StephenAckley²,
吴海斌^1,3,4
1. 中国科学院地质与地球物理研究所, 中国科学院新生代地质与环境重点实验室, 北京 100029
2. Center for Advanced Measurements in Extreme Environments, University of Texas at San Antonio, San Antonio 78249, USA
3. 中国科学院生物演化与环境卓越创新中心, 北京 100044
4. 中国科学院大学, 北京 100049

基金项目: 国家重点研发计划项目（批准号：2016YFA0600504）和国家自然科学基金项目（批准号：41888101和41572165）共同资助


详细信息

作者简介: 田立军, 男, 33岁, 博士后, 同位素水文和古气候研究, E-mail: tianlijun@mail.iggcas.ac.cn

中图分类号: P941.6;P734;P592

收稿日期:2021-02-26
修回日期:2021-03-31
刊出日期:2021-05-30

Precipitation contributions in the mass balance of Arctic and Antarctic sea ice based on stable-isotope tracers

TIAN Lijun^1,2,,
Stephen ACKLEY²,
WU Haibin^1,3,4
1. Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029
2. Center for Advanced Measurements in Extreme Environments, University of Texas at San Antonio, San Antonio 78249, USA
3. Center for Excellence in Life and Paleoenvironment, CAS, Beijing 100044
4. University of Chinese Academy of Sciences, Beijing 100049


MSC: P941.6;P734;P592

--> Received Date: 26 February 2021
Revised Date: 31 March 2021
Publish Date: 30 May 2021


摘要
摘要:极地海冰在全球气候系统中扮演着重要角色。在全球变暖背景下，两极海冰范围呈现相反的变化趋势，即北极海冰显著减少，南极海冰则略有增加，然而目前对两极海冰不对称变化的驱动机制还存在争议。已有研究集中在海冰变化与温度的相互作用上，而对降水在海冰生消过程中所起作用则知之甚少。两极海冰的这种不对称变化可能与降水在海冰生消中起到的不同作用有关：降水在北极主要起到促进海冰消融的作用，而在南极主要起到促使海冰加积生长的作用。降水在两极海冰质量平衡中的贡献可以通过同位素示踪加以厘定，本文详细对比了同位素判别法、线性混合模型和贝叶斯混合模型等研究方法的不同特点及应用上的优劣。利用氧同位素（δ¹⁸O）和氘盈余（d-excess）建立的海冰同位素混合模型，可量化融池在北极海冰质量平衡中的贡献和雪冰在南极海冰质量平衡中的贡献。罗斯海是南极海冰增大最明显的区域，且各种起源的海冰类型齐全（冰针冰、雪冰、附加冰和小板冰），通过三氧同位素（¹⁷O-excess）作为新的示踪同位素，可进一步量化罗斯海海冰质量平衡中四组分的贡献比，探究罗斯海海冰异常变化的生长机制。
关键词: 北极/
南极/
海冰/
质量平衡/
稳定同位素/
同位素混合模型

Abstract:Sea ice is one of the determining parameters of the climate system. In the context of global warming, sea ice extents in the Arctic and Antarctic displayed diverging long-term trends: the Arctic sea ice extent shrunk significantly, while Antarctic sea ice extent increased slightly. However, the driving mechanism for the asymmetrical changes in polar sea ice is not fully understood. Most studies on sea-ice changes have focused on its interaction with temperature, but little is known about the role of precipitation in the processes of sea-ice growth and melt. We found the asymmetrical changes of polar sea ice may be related to the different roles of precipitation: precipitation plays a role in promoting sea-ice melting in the Arctic, while promoting sea-ice accretion in the Antarctic. In this study, the different characteristics of isotope discrimination method, linear mixing model and Bayesian mixing model and their advantages and disadvantages in the applications are compared in detail. The precipitation contribution in the mass balance of polar sea ice could be determined based on stable-isotope tracers. In this study, we compared the different characteristics of the isotopic discriminant method, linear mixing model, and Bayesian mixing model and their advantages and disadvantages in the application. We used oxygen isotope(δ¹⁸O) and deuterium excess(d-excess) to build the isotope mixing model, and we quantified the contribution of melt pond to the mass balance of Arctic sea ice and snow ice to the mass balance of Antarctic sea ice. The most significant contribution of sea ice increase in the Antarctic is from the Ross Sea, and the Ross Sea has a full range of sea ice types with different origins(frazil ice, snow ice, superimposed ice, and platelet ice). We propose that triple oxygen isotope(¹⁷O-excess) could be utilized as a new tracer to quantify the contribution ratios of four components of sea ice in the Ross Sea, and then further explore the growth mechanism of sea ice anomalies in the Ross Sea, Antarctica.
Key words:Arctic/
Antarctic/
sea ice/
mass balance/
stable isotope/
isotope mixing model



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