GLOBAL SEA-LEVEL ACCELERATION
GLOBAL SEA-LEVEL ACCELERATION
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DOI：
10.1029/92jc01133
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发表时间：
1992-08-15
影响因子：
3.6
通讯作者：
DOUGLAS, BC
中科院分区：
文献类型：
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作者：
DOUGLAS, BC
温室效应情景通常预测，未来5或6个十年内海平面将加速上升，幅度为0.1-0.2毫米/年2。长期验潮记录（最少75年）已被检查过去的明显海平面加速（即，与纯线性上升的偏差）以及用于指示检测或验证预测的未来加速度可能需要多长时间。从1905年到1985年的80年间，有10个地理组的23个基本完整的验潮记录可供分析。由此得出表观整体加速度为-0.011（+/-0.012）mm/yr 2。一个更大的，不太均匀的37个记录在相同的10组，92年的平均长度，涵盖了1850年至1991年的141年，得到的加速度为0.001（+/-0.008）毫米/年2。因此，没有证据表明在过去100多年里，无论是在统计上还是与全球变暖相关的数值相比，都有明显的加速。通过将1905-1985年的数据集分为四个相等的时间跨度，可以估计在相对较短的时间内确定全球加速度参数的效果。正式的1西格玛不确定性（约0.2毫米/年2）的全球加速度从这些20年的周期是超过一个数量级大于80年和141年的情况下，由于存在大的年代际和更长的海平面变化。这意味着，在至少几十年的时间里，潮汐测量仪本身不能作为气候变化的主要指标。在95%的置信水平下对特定模型的预测进行建模或区分模型预测将需要更长的时间。如果能够从海平面的强迫机制方面理解海平面的年代际波动，然后从验潮仪记录中删除，则所需的时间可以大大缩短。
Greenhouse warming scenarios commonly forecast an acceleration of sea level rise in the next 5 or 6+ decades in the range 0.1-0.2 mm/yr2. Long tide gauge records (75 years minimum) have been examined for past apparent sea level acceleration (i.e., deviation from a purely linear rise) and for indication of how long it might take to detect or verify a predicted future acceleration. For the 80-year period 1905-1985, 23 essentially complete tide gauge records in 10 geographic groups are available for analysis. These yielded the apparent global acceleration -0.011 (+/-0.012) mm/yr2. A larger, less uniform set of 37 records in the same 10 groups with 92 years average length covering the 141 years from 1850 to 1991 gave for acceleration 0.001 (+/-0.008) mm/yr2. Thus there is no evidence for an apparent acceleration in the past 100+ years that is significant either statistically, or in comparison to values associated with global warming. Estimating how well a global acceleration parameter could be determined in a relatively short time was accomplished by dividing the 1905-1985 data set into four equal time spans. The formal 1-sigma uncertainty (about 0.2 mm/yr2) of global acceleration from these 20-year periods is more than an order of magnitude larger than for the 80- and 141-year cases owing to the existence of large interdecadal and longer variations of sea level. This means that tide gauges alone cannot serve as a leading indicator of climate change in less than at least several decades. Confirming the prediction of a particular model at the 95% confidence level or differentiating between model predictions will take much longer. The time required can be significantly reduced if the interdecadal fluctuations of sea level can be understood in terms of their forcing mechanisms and then removed from the tide gauge records.