| 摘要: |
| 通过对南海北部塔基单站单层强冷空气入侵过程的三维风速记录进行小波分析，研究南海北部一次强冷空气过程，风水平速度和垂向速度的三维相干特征，得到相干结构的生成周期及演变特征．结果表明：在强冷空气入侵过程中，主要阵风扰动相干结构有两类，一是持续时间较短（约1min），发生周期2～10min之间的不连续相干结构；二是持续时间与发生周期几乎相等的连续相干结构，其持续时间和周期在1～13min之间．连续相干结构要比非连续相干结构能量大、分布广、周期变化多．后者在冷锋南侵强风对流天气影响下，扰动作用大，混合加剧，相干结构充分发展，表现出连续的相干结构特征．相干结构的生成及能量分布与阵风风速有密切的关系，阵风风速越大相干结构越活跃．冷锋南侵时，阵风扰动与垂向通量传输呈同向锁相关系，是下沉气流传输的主要扰动因素．风间歇期（小风），有上升气流，主要是西北风动量的脉动下传，感热上传，随着强冷空气的到来，风向转为强冷北风阵风，下沉气流加剧． |
| 关键词: 海洋气象学 南海北部 强冷空气 相干结构 小波变换 小波能谱分析 |
| DOI： |
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| 基金项目:国家“973”资助项目（2015CB452801）；国家自然科学基金资助项目（41275025） |
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| Gustiness features of strong cold air process on northern
South China Sea |
| ZHENG Youren,WU Risheng,HUANG Jian |
| (Information Center of South China Sea. SOA. Guangzhou 510301 . China;Third Institute of Oceanography.?SOA, Xiamen 361005 . China;Guangzhou Institute of Tropical and Marine Meteorology. China Meteorolog,China Meteorological Administration, Guangzhou 510080. China) |
| Abstract: |
| With Kentucky pulsation data and continuous wavelet transform and，'SPAVELET' analysis method, the three-dimensional coherent characteristics of horizontal and vertical wind speed are studied on northern South China Sea. The results show that in the process of strong cold air invasion, there are mainly 2 types of gust disturbance
coherent structures. One is short-time coherent structure with duration of about 1 minute and generation period from2 to 10 minutes, which has discontinuous generation period. The other is continuous variable coherent structures with equivalent duration and generation period from 1 to 13 minutes. Continuous coherent structures have higher energy, wider distribution range and more variable generation period than discontinuous coherent structures. Under the influence of the latter in a cold wind convection weather invading, disturbance, mixed fuel, coherent structure is fully developed, showing the continuous coherent structure characteristics. The generation of coherent structure and energy distribution has close relationship with gusts, the larger the gusts coherent structure of the active. Cold front, invading gust disturbance and vertical flux transmission gone phase-locking relationship, is sinking airflow transmission main disturbance factors. There are updrafts when the wind is intermittent ( breeze) , downward pulsation transmission and upward sensible heat transmission of west and nortfi wind momentum aie dominant. When the wind turns north on the advent strong cold air, strong cold gust prevails and the sinking airflow intensifies. |
| Key words: marine meteorology northern South China Sea strong cold wind coherent structure wavelet analysis wavelet energy spectrun analysis |
