Current state of glaciers in the tropical Andes: a multi-century perspective on glacier evolution and climate change
Current state of glaciers in the tropical Andes: a multi-century perspective on glacier evolution and climate change
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DOI：
10.5194/tc-7-81-2013
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发表时间：
2013-01-01
期刊：
影响因子：
5.2
通讯作者：
Wagnon, P.
中科院分区：
文献类型：
--
作者：
Rabatel, A.;Francou, B.;Wagnon, P.
本文的目的是向业界提供近几十年来对热带安第斯山脉冰川的研究的全面概述，从而了解气候变化背景下冰川的现状。就表面积和长度的变化而言，我们表明，过去三十年来，热带安第斯山脉的冰川退缩是自小冰期（LIA，17世纪中叶至18世纪初）最大程度延长以来前所未有的。就质量平衡的变化而言，尽管一些冰川出现了一些零星的增长，但我们表明，过去 50 年的趋势相当负面，热带安第斯山脉冰川的平均质量平衡赤字比全球范围内计算出的平均质量平衡赤字略高。这一趋势的转折点出现在 20 世纪 70 年代末，年平均质量平衡从 -0.2mw 下降。 e. 1964-1975 年期间为-0.76mw。 e. 1976年至2010年期间。此外，即使目前热带安第斯山脉各地的冰川都在退缩，但值得注意的是，这种退缩现象在低海拔、没有永久堆积区的小冰川上更为明显，并且可能在未来几年/几十年内消失。在玻利维亚、厄瓜多尔和哥伦比亚进行的每月质量平衡测量表明，太平洋表面温度的变化是控制十年时间尺度质量平衡变化的主要因素。 20世纪热带安第斯山脉的降水量没有表现出明显的趋势，因此无法解释冰川退缩。另一方面，在过去 70 年中，温度以 0.10 摄氏度十年(-1) 的显着速度上升。自 20 世纪 70 年代末以来，厄尔尼诺事件的发生频率及其时空发生的变化，加上热带安第斯山脉上空对流层的变暖，可能在很大程度上解释了世界这一地区最近冰川急剧萎缩的原因。
The aim of this paper is to provide the community with a comprehensive overview of the studies of glaciers in the tropical Andes conducted in recent decades leading to the current status of the glaciers in the context of climate change. In terms of changes in surface area and length, we show that the glacier retreat in the tropical Andes over the last three decades is unprecedented since the maximum extension of the Little Ice Age (LIA, mid-17th-early 18th century). In terms of changes in mass balance, although there have been some sporadic gains on several glaciers, we show that the trend has been quite negative over the past 50 yr, with a mean mass balance deficit for glaciers in the tropical Andes that is slightly more negative than the one computed on a global scale. A break point in the trend appeared in the late 1970s with mean annual mass balance per year decreasing from -0.2mw. e. in the period 1964-1975 to -0.76mw. e. in the period 1976-2010. In addition, even if glaciers are currently retreating everywhere in the tropical Andes, it should be noted that this is much more pronounced on small glaciers at low altitudes that do not have a permanent accumulation zone, and which could disappear in the coming years/decades. Monthly mass balance measurements performed in Bolivia, Ecuador and Colombia show that variability of the surface temperature of the Pacific Ocean is the main factor governing variability of the mass balance at the decadal timescale. Precipitation did not display a significant trend in the tropical Andes in the 20th century, and consequently cannot explain the glacier recession. On the other hand, temperature increased at a significant rate of 0.10 degrees C decade(-1) in the last 70 yr. The higher frequency of El Nino events and changes in its spatial and temporal occurrence since the late 1970s together with a warming troposphere over the tropical Andes may thus explain much of the recent dramatic shrinkage of glaciers in this part of the world.