摘要
冰川触地线是内陆冰盖和漂浮冰架的分界线,其位置的准确界定对南极冰川物质平衡计算、冰川动力学建模、冰川变化和海平面变化研究具有重要意义。本文针对Sentinel-1A/B雷达影像数据在南极触地线大规模提取中的应用,基于2020年Sentinel-1A/B雷达影像数据,采用DDInSAR方法对南极触地线进行了大范围的提取,提取触地线约23472 km,结合MEaSURE_GL、MOA_GL2009、MEaSUREs冰流速等数据对触地线提取结果进行综合分析。结果表明:利用DDInSAR方法和Sentinel-1A/B雷达影像数据可以实现对南极触地线长期、高效且较全面的提取,南极不同地区的触地线具有不同的变化特征,存在稳定、回退、前进、消失和冰升等多种变化现象。南极半岛和西南极可以完全应用6 d的Sentinel-1A/B雷达影像数据提取触地线,东南极大部分区域只能应用12 d的Sentinel-1A/B雷达影像数据提取触地线。潮汐运动的强弱影响触地线的提取质量,在西南极的强潮汐区域触地线提取质量较高,在东南极冰盖周围的弱潮汐区域触地线提取质量较差或者结果空缺。南极触地线的提取受冰流速影响较大,当冰流速超过400 m/a时,由于较大冰流速的存在使得触地线提取质量较差甚至无法提取触地线。在利用Sentinel-1A/B雷达影像数据提取南极触地线时,南极半岛和东南极优先选择秋季的影像数据,西南极优先选择夏季的影像数据。
The grounding line is the boundary between the inland grounded ice sheet and the floating ice shelf.Precise extraction of the grounding line has a great significance for the calculation of the material balance of Antarctic glaciers,the modeling of glacier dynamics,glacier changes and sea level changes.This paper aims at the application characteristics of Sentinel-1A/B radar image data in the large-scale extraction of Antarctic grounding line.Based on the Sentinel-1A/B radar image data in 2020 and the DDInSAR method,a large-scale extraction of the Antarctic grounding line is carried out.The grounding line is about 23472 km.Combined with MEaSURE_GL,MOA_Gl2009,MEaSUREs velocity and other data,we have comprehensive analyzed the grounding line extraction result.The result shows that using Sentinel-1A/B radar image data and DDInSAR method can realize long-term,efficient and comprehensive extraction of Antarctic grounding line.The grounding line in different regions of Antarctica has different changing characteristics,including stability,retreat,advance,disappearance and ice rise.In the Antarctic Peninsula and the West Antarctic,we can use the 6 d Sentinel-1A/B radar image data to extract the grounding line.In the large part of the Eest Antarctic,we can only use the 12 d Sentinel-1A/B radar image data to extract the grounding line.The strength of tidal motion affects the quality of the grounding line extraction,the grounding line extraction quality is higher in the strong tidal area of the West Antarctic,and the grounding line extraction quality in the weak tidal area around the East Antarctic ice sheet is poor or the result is vacant.The extraction of the Antarctic grounding line is greatly affected by the ice velocity,when the ice velocity exceeds 400 m/a,the extraction quality of the grounding line is poor or even unable to extract due to the existence of the large ice velocity.When using Sentinel-1A/B radar image data to extract the Antarctic grounding line,the image data of the Antarctic Peninsula and the East Antarctic are preferentially selected during the autumn period,and the image data of the West Antarctic during the summer period are preferentially selected.
作者
赵现仁
邢喆
张峰
郭灿文
王晶
孙毅
马永
赵彬如
王剑
ZHAO Xianren;XING Zhe;ZHANG Feng;GUO Canwen;WANG Jing;SUN Yi;MA Yong;ZHAO Binru;WANG Jian(National Marine Data and Information Service,Tianjin 300171,China)
出处
《测绘通报》
CSCD
北大核心
2023年第9期70-76,共7页
Bulletin of Surveying and Mapping
基金
极地考察业务化与科研(121153000000180037)
国家重点研发计划“科技助力经济2020”重点专项(SQ2020YFF0426316)。
