Atmospheric drivers of sea-level fluctuations and nuisance floods along the mid-Atlantic coast of the USA
Atmospheric drivers of sea-level fluctuations and nuisance floods along the mid-Atlantic coast of the USA
复制标题
美国大西洋中部沿岸海平面波动和滋扰洪水的大气驱动因素
DOI：
10.1007/s10113-017-1156-y
复制
发表时间：
2017
影响因子：
4.2
通讯作者：
V. Ransibrahmanakul
中科院分区：
文献类型：
--
作者：
S. Sheridan;D. Pirhalla;Cameron C. Lee;V. Ransibrahmanakul
随着海平面上升并持续上升，沿海洪水的风险也随之增加。虽然许多研究都研究了特定的极端洪水事件，但很少有研究探讨天气事件与较小的、令人讨厌的洪水事件之间的系统关联。在这项研究中，我们采用天气气候学方法来评估这种联系。我们利用自组织图 (SOM) 分别对两个大气场、海平面气压和 700 hPa 位势高度进行聚类。然后，我们利用这些分类的输出来评估 1979 年至 2012 年期间大气条件对海平面短期波动的影响，以及美国大西洋中部海岸沿线从新泽西州五月角到南卡罗来纳州查尔斯顿的五个潮汐计发生滋扰洪水的可能性。结果显示了倒置气压计效应和表面风力的影响。除此之外，SOM 节点显示出环流与海平面异常之间存在明显的空间连续性，包括一些与相对模糊的压力模式相关的显着海平面异常。此外，还分析了从一天到下一天的过渡，结果表明，快速加深的气旋或持续的陆上水流可能与滋扰洪水的最大可能性有关。 700 hPa 高度的结果通常弱于海平面气压；然而，在某些情况下，对流层中层环流显然可以调节海平面异常与地表环流之间的联系。
As sea levels have risen and continue to rise, the risk of coastal flooding has increased in turn. While many studies have examined specific extreme flooding events, far fewer have explored the systematic associations between weather events and smaller, nuisance flood events. In this research, we take a synoptic climatological approach to assess this connection. We utilize self-organizing maps (SOMs) to separately cluster two atmospheric fields, sea-level pressure and 700-hPa geopotential height. We then utilize the output from these classifications to assess the impact of atmospheric conditions on the short-term fluctuations of sea level for the period 1979–2012, as well as the likelihood of nuisance flood occurrence, at five tidal gauges from Cape May, NJ, to Charleston, SC, along the mid-Atlantic coast of the USA. Results show the impacts of both the inverted barometer effect as well as surface wind forcing. Beyond this, the SOM nodes show a clear spatial continuum of associations between circulation and anomalous sea level, including some significant sea-level anomalies associated with relatively ambiguous pressure patterns. Moreover, the transitions from 1 day to the next are also analyzed, with results showing that rapidly deepening cyclones, or persistent onshore flow, can be associated with the greatest likelihood of nuisance floods. Results are generally weaker with 700-hPa height than sea-level pressure; however, in some cases, it is clear that the mid-tropospheric circulation can modulate the connection between sea-level anomalies and surface circulation.