热带海洋学报 ›› 2016, Vol. 35 ›› Issue (6): 10-18.doi: 10.11978/2016004CSTR: 32234.14.2016004

• 海洋水文学 • 上一篇    下一篇

高频地波雷达观测资料对南海北部海流的数值同化实验*

朱宇航1, 2, 曾学智3, 彭世球1   

  1. 1. 热带海洋环境国家重点实验室(中国科学院南海海洋研究所), 广东 广州 510301;
    2. 中国科学院大学, 北京 100049;
    3. 国家海洋局南海预报中心, 广东 广州 510310;
  • 收稿日期:2016-01-11 修回日期:2016-05-27 出版日期:2016-11-30 发布日期:2016-12-15
  • 通讯作者: 彭世球。Email: speng@scsio.ac.cn
  • 作者简介:作者简介:朱宇航(1990-),男,广东省汕尾市人,硕士研究生,从事资料同化、数值模式研究。E-mail: yuzhu@scsio.ac.cn

Assimilation experiments of high frequency ground wave radar current in the northern coast of the South China Sea

ZHU Yuhang1, 2, ZENG Xuezhi3, PENG Shiqiu1   

  1. 1. State Key Laboratory of Tropical Oceanography (South China Sea Institute of Oceanology, Chinese Academy of Sciences), Guangzhou 510301, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China;
    3. South China Sea Marine Prediction Center, State Oceanic Administration, Guangzhou 510310, China;
  • Received:2016-01-11 Revised:2016-05-27 Online:2016-11-30 Published:2016-12-15
  • Contact: PENG Shiqiu. E-mail: speng@scsio.ac.cn
  • Supported by:
    *感谢南海海洋研究所的高性能计算中心为本文数值模拟提供的技术支持。

摘要: 文章利用基于区域海洋模式(ROMS)的三维变分同化系统, 将双站(博贺站和斗龙站)高频地波雷达的表层海流观测数据同化进模式中, 并通过敏感性试验研究了观测覆盖率对同化效果的影响以及同化间隔对同化效果持续性的影响。结果表明, 同化高频地波雷达表层海流观测数据能显著改善模式对表层海流的模拟。当观测覆盖率大于40%时, 不同的观测覆盖率的同化效果几乎无差别, 这表明模式背景误差协方差能够很好地弥补高频地波雷达在空间上的缺测信息。试验结果还表明同化效果的持续性受到同化间隔的影响: 过频繁的同化会造成模式初始场动力不平衡加剧, 使得同化效果的持续性变差, 而过大的同化间隔则会使同化效果在下一次同化到来前消失。当同化间隔取6h或12h时, 同化效果的持续性达到最优。同化对模式预报的改善持续的时长为4~6h。

关键词: 高频地波雷达, 三维变分同化, 海表流场同化, 区域海洋模式

Abstract: Based on the Regional Oceanic Modeling System (ROMS) and multi-scale three-dimensional variational data assimilation scheme, the sea surface currents (SSCs) observed by double HF Radar stations Bohe and Doulong are assimilated into the ocean model. The effect of assimilation using different observation coverages and the sustainability of assimilation effect using different assimilation intervals are investigated through sensitivity experiments. The results show that the assimilation of HF Radar SSC significantly improves the SSC simulation. The experiments show no significant difference under different coverages of SSC observations when the coverage is over 40%, which indicates the background error covariance is able to make up for the missing data of the HF Radar SSC in space. The results also show that the sustainability of assimilation effect is influenced by the interval of assimilation: assimilating data too often will exacerbate the dynamic imbalance of the initial field, which makes the sustainability of the improvement worse, while a too large interval of assimilation will lose the assimilation effect before the next assimilation starts. The sustainability of the improvement in assisimilation achieves the best optimization when the assimilation interval is 6 or 12 hours. The sustainability of the improvement of model forecast after the assimilation lasts for 4 to 6 hours.

Key words: high frequency ground wave radar, three-dimensional variational assimilation, sea surface current assimilation, regional oceanic modeling system