地理科学进展 ›› 2015, Vol. 34 ›› Issue (10): 1241-1249.doi: 10.18306/dlkxjz.2015.10.004

• 气候变化 • 上一篇    下一篇

2000-2013年西藏纳木错湖冰变化及其影响因素

勾鹏1,2, 叶庆华1,*(), 魏秋方3   

  1. 1. 中国科学院青藏高原研究所,青藏高原环境变化与地表过程重点实验室,北京 100101
    2. 中国科学院大学资源与环境学院,北京 100049
    3. 中国科学院遥感与数字地球研究所,北京 100101
  • 收稿日期:2015-02-01 接受日期:2015-04-01 出版日期:2015-10-20 发布日期:2015-10-20
  • 通讯作者: 叶庆华 E-mail:yeqh@itpcas.ac.cn。,
  • 作者简介:

    作者简介:勾鹏(1987-),男,山东东营人,博士研究生,主要从事青藏高原湖冰遥感研究,E-mail: gougeng@itpcas.ac.cn

  • 基金资助:
    国家自然科学基金项目(41071254);国家自然科学基金重大国际合作研究项目(41120114001);科技基础性工作专项项目(2013FY111400-2);中国科学院资源环境科学与技术局青年人才类项目(KZCX2-EW-QN104)

Lake ice change at the Nam Co Lake on the Tibetan Plateau during 2000-2013 and influencing factors

Peng GOU1,2, Qinghua YE1,*(), Qiufang WEI3   

  1. 1. Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, CAS, Beijing 100085, China
    2. College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
    3. Institute of Remote Sensing and Digital Earth, CAS, Beijing 100101, China
  • Received:2015-02-01 Accepted:2015-04-01 Online:2015-10-20 Published:2015-10-20
  • Contact: Qinghua YE E-mail:yeqh@itpcas.ac.cn。,

摘要:

湖冰物候事件是气候变化的敏感指示器。本文以西藏纳木错湖为研究对象,基于MODIS多光谱反射率产品数据监测了2000-2013年纳木错湖冰冻融日期,并结合多个气象站点的气象数据和实测湖面温度、湖面辐射亮温分析验证了湖冰变化的原因。纳木错湖冰变化较好地响应了区域气候变暖:开始冻结日期延迟和完全消融日期提前使湖冰存在期显著缩短(2.8 d/a)、湖冰冻结期增长、湖冰消融期缩短,其中消融期变化最为明显,平均每年缩短3.1 d。湖冰冻融日期的变化表明:2000年后纳木错湖冰冻结困难,消融加速,稳定性减弱。纳木错湖冰变化主要受湖面温度、湖面辐射亮温和气温变化的影响,它们可以作为气象因子来解释区域气候变化。

关键词: 湖冰, 遥感, 反射率阈值法, 辐射亮温, 青藏高原

Abstract:

Lake ice is a sensitive proxy to climate variability as has been shown through observations and modeling. In this study, we used in-situ and satellite data to analyze lake ice change at the Nam Co Lake in Tibet in 2000-2013. The results from Moderate Resolution Imaging Spectrometer (MODIS) data showed that lake ice phenology changed significantly at the Nam Co Lake in the studied time period. The postponing freeze onset (FO) and advancing water clear of ice (WCI) dates were both obvious, resulting in the dramatic reduction of ice existence period (IEP) (2.8 days/year). Melt duration (MD), which stands for lake ice melting speed, was the most sensitive indicator of Nam Co Lake ice durations and MD was shortened by 3.1 days/year through the study period. Lake ice change at the Nam Co Lake was affected by regional climate variations, including air temperature and wind speed changes. In this study, daily air temperature from two automatic weather stations on the lakeshore showed highly consistent trend with lake ice phenology—both freeze onset (FO) and melt onset (MO) synchronized with air temperature variation. High wind speed in winter accelerates freezing. Lake ice tensile force rather than wind force can force the ice into pieces during the formation period. Lake ice phenology acts as a sensitive proxy of regional climate and can serve as an indicator of regional climate change. Further study on lake ice in the Tibetan Plateau is significant because of its sensitive response to climate change.

Key words: lake ice, remote sensing, reflectivity threshold, brightness temperature, Tibetan Plateau