Relative sea-level projections in Canada and the adjacent mainland United States
Relative sea-level projections in Canada and the adjacent mainland United States
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加拿大和邻近美国大陆的相对海平面预测
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
M. Craymer
中科院分区：
文献类型：
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作者：
T. James;J. Henton;L. Leonard;A. Darlington;D. Forbes;M. Craymer
相对于1986-2005年，提供了加拿大59个地点和邻近的美国大陆10个地点到21世纪的相对海平面预测。这些预测是根据政府间气候变化专门委员会第五次评估报告中的代表性浓度路径情景作出的。它们包括海洋热膨胀（空间效应）、陆地冰融化和排放以及人为影响的贡献。最大排放情景RCP 8.5的全球平均海平面预测在2100年为74厘米（5%-95%范围为54至98厘米）。全球定位系统（GPS）的垂直地面运动的测量被纳入相对海平面预测。在这里介绍的地区，垂直的陆地运动，主要是由冰川均衡调整，在确定预计的相对海平面变化发挥了突出的作用。在东海岸，地壳沉降，加上动态海洋学的变化，产生相对海平面预测，类似于或大于全球平均预测大西洋加拿大和新英格兰的大部分地区。在西海岸，大多数相对海平面预测小于全球平均值，尽管华盛顿州和不列颠哥伦比亚省南部的一些地点的相对海平面预测与全球值相似。预测的相对海平面上升的最大变化发生在加拿大北方，这是由于冰川均衡调整造成的现今地壳隆起的空间差异非常大。在这里，预计2100年的相对海平面变化范围从哈德逊湾陆地快速上升的海平面下降约1米（中值），到博福特海岸陆地下沉的海平面上升约70厘米。南极西部冰盖部分崩塌的情景使海平面比RCP8.5再上升65厘米，在对海平面上升风险的容忍度较低时可能适合考虑。这里给出的相对海平面预测仅提供了本世纪的轨迹，但IPCC AR 5预测未来几个世纪全球海平面将继续上升。随着对海平面上升的各个组成部分的了解的加深，有必要偶尔更新相对海平面预测，并重新评估对基础设施、生境和海洋航行的影响。
Relative sea-level projections are provided for 59 locations in Canada and 10 in the adjacent mainland United States through the 21 century, relative to 1986-2005. The projections are based on the Representative Concentration Pathway (RCP) scenarios of the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5). They include contributions from the thermal expansion of the ocean (steric effect), land ice melting and discharge, and anthropogenic influences. The global mean sea-level projection for RCP8.5, the largest emissions scenario, at 2100 is 74 cm (5%-95% range is 54 to 98 cm). Global Positioning System (GPS) measurements of vertical land motion are incorporated into the relative sea-level projections. In the regions presented here, vertical land motion, largely arising from glacial isostatic adjustment, plays a prominent role in determining projected relative sea-level change. On the east coast, crustal subsidence, combined with dynamic oceanographic changes, generates relative sea-level projections that are similar to or larger than the global mean projections in large parts of Atlantic Canada and New England. On the west coast, most relative sea-level projections are smaller than the global means, although some sites in Washington State and southern British Columbia feature relative sea-level projections similar to the global values. The largest variation in projected relative sea-level rise occurs in northern Canada, owing to the very large spatial differences in present-day crustal uplift due to glacial isostatic adjustment. Here, projected relative sea-level at 2100 varies from around 1 m of sea-level fall (median values) where land is rising quickly on Hudson Bay, while it reaches about 70 cm of sea-level rise on the Beaufort coast where the land is subsiding. A scenario featuring partial collapse of a portion of the West Antarctic Ice Sheet provides an additional 65 cm of sea-level rise to RCP8.5, and may be appropriate to consider when tolerance to the risk of sea-level rise is low. The relative sea-level projections given here only provide a trajectory through this century, but the IPCC AR5 projects continued global sea-level rise in coming centuries. As understanding improves of the various components of sea-level rise, it will be necessary to update, on an occasional basis, the relative sea-level projections and re-evaluate the implications for infrastructure, habitat, and marine navigation.