Forcing Mechanisms Associated With the Destructive Record-High 2008 Ocean Wave in Toyama Bay
Forcing Mechanisms Associated With the Destructive Record-High 2008 Ocean Wave in Toyama Bay
复制标题
与 2008 年富山湾破坏性创纪录海浪相关的强迫机制
DOI：
10.1029/2022ea002750
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发表时间：
2023
影响因子：
3.1
通讯作者：
Satoru Okajima
中科院分区：
文献类型：
--
作者：
Shohei Nomura;Bunmei Taguchi;Hitoshi Tamura;Satoru Okajima
涌浪可能会导致沿海灾害。这种危害的一个独特例子是日本海富山湾每隔几年就会观测到一次的赖和波（Yorimawari-Nami）事件。基于沿海现场观测和海浪后报模拟，研究了2008年创纪录的YM波事件的强迫机制，重点关注驱动日本海风海和海浪的表面风和大气扰动。对大气中尺度数据的详细分析以及气旋跟踪和波谱分析表明，2008年的事件是由东北和北海道地区异常持续的偏北风推动的，与两个连续的温带气旋有关，穿过日本海并伴随着明确的上对流层截止低点。第一个气旋产生了最初的偏北风，迫使北海道岛西北方向移动，这与向富山湾向南传播的风海方向一致。最初的回风赶上了第二个气旋，导致大偏北风分量（>12 ms−1）区域的延伸，持续时间超过 24 小时，并由于截止低压向南延伸而向南延伸，其传播速度与波群速度相匹配，从而增强了最初产生的涌浪。
Swells can cause coastal hazards. A unique example of such hazards is the Yorimawari‐Nami (YM‐wave) events that have been observed once every few years in Toyama Bay in the Japan Sea. Based on coastal in situ observations and hindcast simulations of ocean waves, the forcing mechanism for the record‐high 2008 YM‐wave event is investigated, focusing on the surface winds and the atmospheric disturbances that drove wind seas and swells in the Japan Sea. Detailed analysis of atmospheric mesoscale data along with cyclone tracking and wave spectral analysis revealed that the 2008 event was forced by an exceptionally persistent northerly wind off the Tohoku and Hokkaido regions associated with two successive extra‐tropical cyclones, passing across the Japan Sea and accompanying a well‐defined upper‐tropospheric cut‐off low. The first cyclone generated the initial northerly wind forcing toward the northwest of Hokkaido Island that was aligned with the direction of southward‐propagating wind seas toward Toyama Bay. This initial fetch caught up with the second cyclone, leading to an extension in the area of a large northerly wind component (>12 ms−1) that lasted longer than 24 hr and extended southward due to the southward extension of the cut‐off low with a propagation speed that matches the wave group velocity, reinforcing the initially generated swell.