基于SAR波模式数据的沉船事故海浪要素分析

涌浪是近海波浪系统中的重要组成部分,因其持续时间长且蕴含巨大能量,可导致渔船沉没事故,造成生命、财产和环境危害。合成孔径雷达(SAR)能够对海浪成像并提供二维方向谱,成为遥感海浪的重要手段。本研究将利用欧空局环境卫星搭载的高级合成孔径雷达(ENVISAT-ASAR)的波模式轨道数据提供的涌浪信息,量化涌浪在中国近海浪致渔船沉没事故中的影响。首先,对浪致渔船沉没事故、ASAR数据和模式数据进行时空匹配;其次,对匹配成功的数据进行对比统计,分析涌浪要素特征,量化涌浪影响。结论:渔船沉没事故发生时,(1)天气形势多为冷空气、温带气旋或台风;(2)风浪、涌浪混合有效波高绝大部分大于2.0 m,涌浪波高占比在50%以上;(3)风浪和涌浪夹角45°,当同时满足(2)和(3)条件时更容易发生沉船事故。

Analysis of wave factors in shipwreck accidents based on SAR wave mode data

Swell is an important part in near shore wave systems and it can cause fishing shipwreck accidents due to its long duration and huge energy. Synthetic aperture radar (SAR) can image ocean waves and provide 2-dimentional wave spectra, making it an important remote tool for observing waves. In this study, swell information from orbital wave mode data of European Space Agency (ESA) ENVISAT-ASAR was used to quantify the effect of swells in wave-caused shipwreck accidents in China coastal seas. First, temporal and spatial match-up data among the wave-caused shipwreck accidents, ASAR wave mode data and model data were generated; and then the swell factors of match-up data were compared and analyzed. Conclusions are:when the shipwreck accidents happened, (1) weather systems were mostly cold air, extratropical cyclone or typhoon; (2) most mixed significant wave heights of wind waves and swells were larger than 2.0 m with swell portion greater than 50%; (3) the intersection angles between propagate directions of wind waves and swells were greater than 45°, and the shipwreck accidents happened more likely when conditions (2) and (3) were both satisfied.