Reed Andra J, Mann Michael E, Emanuel Kerry A, Lin Ning, Horton Benjamin P, Kemp Andrew C, Donnelly Jeffrey P
Department of Meteorology, The Pennsylvania State University, University Park, PA 16802;
Department of Meteorology, The Pennsylvania State University, University Park, PA 16802; Earth Environmental Systems Institute, The Pennsylvania State University, University Park, PA 16802;
Proc Natl Acad Sci U S A. 2015 Oct 13;112(41):12610-5. doi: 10.1073/pnas.1513127112. Epub 2015 Sep 28.
In a changing climate, future inundation of the United States' Atlantic coast will depend on both storm surges during tropical cyclones and the rising relative sea levels on which those surges occur. However, the observational record of tropical cyclones in the North Atlantic basin is too short (A.D. 1851 to present) to accurately assess long-term trends in storm activity. To overcome this limitation, we use proxy sea level records, and downscale three CMIP5 models to generate large synthetic tropical cyclone data sets for the North Atlantic basin; driving climate conditions span from A.D. 850 to A.D. 2005. We compare pre-anthropogenic era (A.D. 850-1800) and anthropogenic era (A.D.1970-2005) storm surge model results for New York City, exposing links between increased rates of sea level rise and storm flood heights. We find that mean flood heights increased by ∼1.24 m (due mainly to sea level rise) from ∼A.D. 850 to the anthropogenic era, a result that is significant at the 99% confidence level. Additionally, changes in tropical cyclone characteristics have led to increases in the extremes of the types of storms that create the largest storm surges for New York City. As a result, flood risk has greatly increased for the region; for example, the 500-y return period for a ∼2.25-m flood height during the pre-anthropogenic era has decreased to ∼24.4 y in the anthropogenic era. Our results indicate the impacts of climate change on coastal inundation, and call for advanced risk management strategies.
在气候变化的背景下，美国大西洋沿岸未来的洪水泛滥将取决于热带气旋期间的风暴潮以及这些风暴潮发生时相对海平面的上升。然而，北大西洋盆地热带气旋的观测记录太短（公元1851年至今），无法准确评估风暴活动的长期趋势。为了克服这一限制，我们使用代理海平面记录，并对三个CMIP5模型进行降尺度处理，以生成北大西洋盆地大型合成热带气旋数据集；驱动气候条件的时间跨度为公元850年至公元2005年。我们比较了纽约市在人类活动前时代（公元850 - 1800年）和人类活动时代（公元1970 - 2005年）的风暴潮模型结果，揭示了海平面上升速率增加与风暴洪水高度之间的联系。我们发现，从公元850年到人类活动时代，平均洪水高度增加了约1.24米（主要由于海平面上升），这一结果在99%的置信水平上具有显著性。此外，热带气旋特征的变化导致了纽约市产生最大风暴潮的风暴类型极端情况增加。因此，该地区的洪水风险大幅增加；例如，在人类活动前时代，约2.25米洪水高度的500年一遇事件在人类活动时代已降至约24.4年一遇。我们的结果表明了气候变化对沿海洪水泛滥的影响，并呼吁采取先进的风险管理策略。
