Twentieth century sea-level rise inferred from tide gauge, geologically derived and thermosteric sea-level changes
Twentieth century sea-level rise inferred from tide gauge, geologically derived and thermosteric sea-level changes
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DOI：
10.1016/j.quascirev.2013.06.010
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发表时间：
2013-09
影响因子：
4
通讯作者：
M. Nakada;J. Okuno;M. Ishii
中科院分区：
文献类型：
--
作者：
M. Nakada;J. Okuno;M. Ishii
从验潮仪和/或盐沼沉积序列得到的13个地点的相对海平面变化，以及至少在过去∼200年期间相对海平面变化的信息，被用来推断20世纪(卫星时代之前)全球海平面上升的速度和原因，方法是将空间上不均匀的热定常海平面变化和最近对山脉冰川和两极冰盖融化的估计结合起来。本文所采用的方法的主要优点是可以避免GIA(冰川均衡调整)校正中的模型依赖性，并且可以校正依赖于每个位置的任何稳定的构造效应。我们首先估计了20世纪每个RSL观测点的海平面上升加速度，然后估计了海平面加速度与温差海平面上升之间的残差。对空间上不均匀的残差进行了检验，以推断由于山脉冰川和极地冰盖融化而导致的RSL上升速率。残差与预测融化速率之间的比较完全支持政府间气候变化专门委员会第四次评估报告(气专委2007年报告)对融化的估计，并不需要格陵兰冰盖的显著融化。然而，山地冰川和/或南极冰盖可能的等值海平面上升可能是∼0.3mmyyr−1，比政府间气候变化专门委员会2007年报告的首选估计值(∼0.7mmyyr−1)大0.3 mm yyr−1，总的海平面上升幅度为−1.0mmyyr∼1。−1的额外融化主要是由于与∼200年的长验潮记录进行了比较。此外，本研究还表明，在1990年海平面快速加速之前，全球平均温差海平面上升为∼0.3万亿毫米/年−1。
Relative sea-level (RSL) changes at thirteen sites derived from tide gauge and/or salt-marsh sediment sequences, with information for RSL changes during at least the past ∼200 years, are used to infer the rates and causes of the global sea-level rise in the twentieth century (pre-satellite era) by incorporating spatially non-uniform thermosteric sea-level change and recent estimates for the melting of mountain glaciers and both polar ice sheets. The main advantage of the method adopted here is that we can avoid a model-dependence in the GIA (glacial isostatic adjustment) correction and any steady tectonic effect depending on each location can be corrected for. We first estimate the acceleration of sea-level rise in the twentieth century at each RSL observation site, and then evaluate the residuals between the sea-level acceleration and thermosteric sea-level rise. The spatially non-uniform residuals are examined to infer the rates of RSL rise due to the melting of mountain glaciers and polar ice sheets. The comparison between the residuals and the predicted rates for the melting wholly supports the estimates for the melting by the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC 2007 Report), and does not require a significant melting from the Greenland ice sheet. However, the possible equivalent sea-level rise for mountain glaciers and/or Antarctic ice sheet may be ∼0.3 mm yr−1larger than the preferred estimate by IPCC 2007 Report (∼0.7 mm yr−1), and the total one is ∼1.0 mm yr−1. The additional melting for ∼0.3 mm yr−1is due to the comparison mainly for Brest with long tide gauge records of ∼200 years. Also, the present study indicates that the global mean thermosteric sea-level rise before the rapid sea-level acceleration occurred at 1990 is ∼0.3 mm yr−1.