| 摘要: |
| 利用高分辨率(1/18°)的POM(Princeton Ocean Model)模式数值模拟结果, 结合观测数据分析了苏北浅滩外侧潮汐锋的季节分布特征和变化规律。研究结果表明, 苏北浅滩外侧潮汐锋的季节变化特征显著, 春末开始出现, 夏季底层温度锋强度最大且锋区位置较稳定, 锋区宽度约40km, 平均强度约0.35℃/km, 秋、冬季随上层海洋湍流垂向混合的加强, 潮汐锋逐渐减弱至消失不见。对比实测数据和模拟结果发现, 沿34°N断面, 夏季潮汐锋区附近等温线明显抬升, 存在由陡峭地形和分层流体的内埃克曼效应共同作用形成的上升流现象。次表层海水出现低温冷水区, 位于122.2°E附近。跨锋区断面的温度和流场分布特征同浅水区强烈的潮混合过程密切相关, 斜压在锋面处产生了较强的南向流动。本研究结果促进了对苏北浅滩外侧陆架潮汐锋结构特征的认识, 为研究黄海西部生态环境的动力过程影响提供参考。 |
| 关键词: 苏北浅滩 潮汐锋 潮汐锋季节变化 上升流 |
| DOI：10.11759/hykx20151108001 |
| 分类号: |
| 基金项目:国家自然科学基金项目(41376006); 中国科学院战略性先导科技专项(XDA11020305); 国家重点研发计划项目(2016YFA0601301);国家重点基础研究发展计划项目(2011CB403606) |
|
| Analysis on seasonal variations and structures of the tidal front outside of the Subei Shoal |
|
CHENG Xue-li,SUN Qun,WANG Yu-heng,YANG Yang
|
| Abstract: |
| This research studies the tidal front out of the Subei Shoal because this tidal front has an important mesoscale physical process that affects the ecological environment in the Western Yellow Sea in summer. The changes have important effects on the marine environment, marine ecosystem, navigation and fishery. In this paper, the high resolution (1/18)° simulated results from the Princeton Ocean Model (POM) were used to study the seasonal distributions and characteristics of the tidal front in the Subei Shoal. The results show that the tidal front outside the Subei Shoal has significant seasonal variations. The tidal front appears in late spring and then gradually become stronger. The strength of the tidal front reaches a maximum and its position is stable in summer, the width of which is about 40 km, and the sea surface temperature (SST) gradient strength of tidal front is 0.35℃/km. As the vertical mixing increased due to surface cooling and winds, the tidal front gradually became weaker in fall and eventually disappeared in winter. In comparison with the observations, the isotherms near the frontal zone rise towards the land along the 34°N section, causing an upwelling due to the combined effects of the inner Ekman transport and topographical change. In addition, the cold-water center in the sublayer was near 122.2°E. The temperature and velocity across the tidal front are closely related to the vertical mixing, and a southern jet appeared along the front because of the baroclinicity effect. The research results increased the understanding of the structures of the tidal front out of the Subei Shoal and provides a reference on studying the dynamical processes of the ecological environment in the Western Yellow Sea. |
| Key words: the Subei Shoal tidal front seasonal variation upwelling |
