极地研究

极地研究 ›› 2021, Vol. 33 ›› Issue (3): 363-373.DOI: 10.13679/j.jdyj.20200052

• 研究论文 • 上一篇    下一篇

基于Elmer/Ice对玛丽伯德地西部区域的冰盖数值模拟

杨树瑚，徐佳鑫，许德锐，韩彦岭，张云，洪中华   

  1. 上海海洋大学信息学院，上海 201306
  • 收稿日期:2020-07-06 修回日期:2020-09-26 接受日期:2020-10-13 出版日期:2021-09-30 发布日期:2021-10-12
  • 基金资助:
    国家自然科学基金(41506213, 41376178, 41401489)

Numerical simulation of ice sheets in the western region of Marie Byrd Land using Elmer/Ice

Yang Shuhu, Xu Jiaxin, Xu Derui, Han Yanling, Zhang Yun, Hong Zhonghua   

  1. College of Information Technology, Shanghai Ocean University, Shanghai 201306, China
  • Received:2020-07-06 Revised:2020-09-26 Accepted:2020-10-13 Online:2021-09-30 Published:2021-10-12

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摘要： 西南极冰盖对全球气候变化和海平面升高有着重要的影响, 其动力学和热力学过程是极地研究的重点之一。冰盖数值模式的模拟可以在缺乏观测数据的情况下获得研究区域的动力学和热力学过程, 已经成为研究南极的一种重要手段。西南极玛丽伯德地靠近福特山脉和罗斯冰架, 本文使用Elmer/Ice模拟了玛丽伯德地西部区域的冰流速场、温度场和应力场。研究发现, 该区域冰盖底部温度场变化较小, 大部分都达到了压力融点, 只有小部分区域的冰盖底部仍处于压力融点以下。使用三个不同的地热通量(80 mW×m−2, 100 mW×m−2, 120 mW×m−2)模拟得到的底部温度场无明显差异。冰盖表面流速较快, 冰盖表面的冰总体上从地势较高的区域流向地势较低的区域, 垂直方向对表面冰流速影响最大; 冰盖底部应力场的大小大致和冰厚的变化相反。通过高程剖面图简要分析了冰流速和冰盖应力场的变化原因, 认为冰下深谷的存在可能对冰盖流速场和应力场有很大的影响。

关键词: 西南极冰盖, 玛丽伯德地, Elmer/Ice, 冰盖温度, 冰流速场, 冰盖应力场

Abstract:

The West Antarctic ice sheet has an important impact on global climate change and sea level rise and its dynamics and thermodynamics are among the focuses of polar research. Simulation of the ice sheet using numerical modeling constrains a study area’s dynamics and thermodynamics in the absence of observation data and it has become an important means of studying Antarctica. The Marie Byrd Land in West Amtarctica is near the Ford Mountain Range and the Ross Ice Shelf. In this paper, Elmer/Ice is used to simulate Marie Byrd Land’s western region’s ice velocity field, temperature field and pressure field. The study showed that the temperature field at the bottom of the ice sheet in this area was almost uniform, most of the ice bottom reached the pressure melting point, and only a small part of the ice bottom was still below the pressure melting point. There was no obvious difference in the bottom temperature fields among three simulations respectively using different geothermal fluxes (80 mW×m−2, 100 mW×m−2, 120 mW×m−2). The surface ice velocity was also simulated in the x, y, and z directions. The ice sheet’s simulated surface velocities were 0.012 – 744.7 m×a–1. Model results indicate that the vertical direction has the greatest impact on the surface ice velocity; the stress field at the bottom of the ice sheet is roughly inversely proportional to the ice thickness. The z-direction profile from Bedmap 2 was used to analyze the causes of changes in ice flow velocities and ice sheet stress fields, and it is inferred that the existence of deep valleys under the ice may have a strong influence on the ice sheet velocity fields and stress fields.

Key words:

Antarctic ice sheet, Marie Byrd Land, Elmer/Ice, ice sheet temperature, ice velocity field, ice sheet pressure field