自然-地球科学》(Nature Geoscience)上周日发表的一项研究结果显示,全球海平面在2005年到2011年间上升了16.8毫米(即大约三分之二英寸),主要原因是极地冰盖和高山冰川的加速融化。科学家们说,这些发现与已经被观察到的长期趋势一致,但是这项研究仅包含了几年的观察结果,因此得出的结论受限。不过,这项研究确实解决了因海平面测量方法不同引发的一些长期分歧。该研究由美国国家科学基金会(National Science Foundation)和美国国家航空航天局(National Aeronautics and Space Administration,简称NASA)资助完成。
Accelerated melting of polar ice sheets and mountain glaciers was the driving
factor behind a rise in the global sea level of 16.8 millimeters, or about two-thirds of an inch, between 2005 and 2011, according to a study published Sunday in Nature Geoscience.
科学家们想要弄清楚的是,海平面的变化中,有多少与融水增多有关,又有多少与水的升温膨胀有关。之前的计算结果显示,海平面的上升变化中,有一半是冰川消融造成的。最新的研究结论是,从2005年到2011年,这个因素所占的比重更接近75%。
The findings are
consistent with observed longer-term trends, but the study encompasses only a few years of observations, limiting its conclusions, scientists said. The study, funded by the National Science Foundation and the National Aeronautics and Space Administration, does
resolve long-standing discrepancies that arose from different methods of measuring sea levels.
德克萨斯大学奥斯汀分校(University of Texas at Austin)地球物理学家、该研究成果的作者之一威尔逊(Clark R. Wilson)说,从2005年开始,格陵兰岛的融化速度加快,这可能就是最近几年流入海洋的融水量增多的原因。
Scientists want to establish how much of the sea-level change relates to increased melt water, and how much relates to the water expanding as it warms up. Previous calculations indicated that melting might
contribute about half of the increase. The latest study concludes that for the period 2005-2011 the
contribution was closer to 75%.
过去20年的数据显示,海平面每年上升大约3.1毫米。特定的短期数据可能略低于或略高于这个水平,比如最近这次研究显示,海平面每年上升2.4毫米。
'There was an increase in the melting rate in Greenland starting in 2005 and that is probably the
underlying story why' a larger quantity of melt water has poured into the oceans in recent years, said Clark R. Wilson, geophysicist at the University of Texas at Austin and co-author of the study.
科学家们通过安装在卫星上的雷达来估测海平面的整体变化。这种雷达能够测量海平面的高度。他们还可以通过把两个单独测量出的因素结合来估量海平面变化,这两个因素分别是新增融水及其他来源的水的质量,以及热膨胀导致的海平面上升。
Data from the past two decades suggest a sea level increase of about 3.1 millimeters per year. Shorter-term snapshots