高频地波雷达海流应用研究

发布时间：2018-06-03 17:21

本文选题：高频地波雷达 + 海流　；参考：《武汉大学》2014年博士论文

【摘要】：高频地波雷达是近40年来发展起来的可以监测海洋表面动力学参数的海洋遥感设备。其利用海洋表面对高频电磁波的一阶散射和二阶散射机制,可以从雷达回波中提取流场、风场、浪场等海洋动力学参数信息,实现对海洋环境大范围、高精度和全天候的实时监测,是对现有海洋遥感设备和遥感手段的必要补充,被认为是专属经济区内最廉价有效的海洋环境监测手段之一。高频地波雷达观测得到的海流是一定深度的海洋表面的平均海流,经过无数次海上对比验证实验已经证明了高频地波雷达海流观测结果的准确性,目前高频地波雷达海流观测已达到业务化运行水平并在国家各个职能部门中可能发挥重要的作用。国内用于海洋环境监测的高频地波雷达研究开始于1987年。武汉大学在“九五”、“十五”和“十一五”国家863计划的支持下,研制出了成熟的OSMAR(Ocean State Monitoring and Analyzing Radar)系列高频地波雷达产品。本文在国家十二五“863计划”海洋领域重大课题“分布式高频超视距雷达探测与组网技术研究”的支持下,利用布设在浙江舟山海域及福建台湾海峡西南海域的高频地波雷达OSMAR观测得到的海流结果进行相关研究。主要研究内容如下： 1)通过对分布于浙江舟山群岛的朱家尖和嵊山两个高频地波雷达站在2005年8月对比验证实验期间观测得到的海流数据进行准调和分析,首次给出了基于全覆盖观测的舟山外海的表层潮流的空间分布特性。分析结果表明：舟山外海的潮流属于正规半日潮,且浅水分潮的影响比较大。潮流运动形式以往复流为主。最大可能流速分布从东北方向致西南方向逐渐减弱。实验期间近海岸的余流比远海岸的大,方向基本都是北偏东,并且随着距离的增加其北偏东的角度逐渐增大,呈右旋趋势。水深的分布对浅水分潮的影响分布、潮流运动形式分布、最大可能流速分布,余流分布等都有一定的影响 2)通过对福建省东山和龙海高频地波雷达站观测得到3天的矢量海流进行准调和分析,研究了台湾海峡西南海域表面潮流空间分布特性。分析结果表明：该海域潮流性质以正规半日潮流为主。分潮的潮流椭圆受两只潮波的共同影响,潮流椭圆的主轴方向和海岸线平行。最大可能流速从东北向西南逐渐增大并和实测最大海流的趋势基本一致。余流受台湾海峡暖流的影响主要指向东北方向。地形对潮流的空间分布也有很大的影响。 3)利用调和分析方法对2个月的高频地波雷达海流结果进行了分析,给出福建台湾海峡西南海域的潮流的空时分布特性,给出了单点海流序列的调和分析结果,同时分析了M2分潮潮流椭圆、最大流速以及余流的空间分布特征。分析结果表明：该海域潮流性质以正规半日潮流为主,M2分潮潮流椭圆在靠近海岸线的潮流椭圆走向呈NE-SW,和台湾海峡的轴线基本一致。远离海岸线的潮流椭圆的走向慢慢向N-S转变,潮流运动形式以往复流为主。最大流速分布受强烈的东北季风影响,其变化范围较大,特别是在台湾浅滩,最大流速达到了150cm/s。余流也受东北季风影响较大,其方向基本指向西南方向。 4)分析了狮子山台风期间表层海流对台风的响应过程。分析结果表明：狮子山台风使得高频地波雷达回波多普勒谱的一阶峰明显展宽,并且一阶峰展宽的振荡周期由半日潮周期逐渐变为全日潮周期。第8距离元的回波信噪比增幅约为2-10dB。观测海域的南部及东北部的最大流速增幅达100cm/s,且关于狮子山台风路径近乎对称。台风路径右边的增幅要略大于左边的增幅。台风期间观测海域的流场的旋度和散度值都有大幅度增加,其最大值增幅几乎翻倍。台风过后,散度和旋度的值比台风来临前的要低很多,台风过后2.5天后逐步恢复到正常水平。 5)利用布设在高频地波雷达福建示范区的东山、龙海两个雷达站的约3天的海流数据进行矢量正交经验函数分析。分析结果表明前三个模态的方差贡献率分别为91%、4%和1.4%,累计方差贡献率达到了96%,为主要模态。模态1的空时分布特性表明模态1主要反映了半日潮流的信息并且在一定程度上反映了水深分布的信息；模态2的空时分布特性表明模态2主要反映了风生流以及流场旋转特性的信息；模态3的空时分布特性表明模态3主要反映了上升流的信息。 6)对狮子山台风期间的数据(2010年8月30日-2014年9月4日)进行ComplexEOF分析,分析结果表明前三个模态的方差贡献率达到了89.51%,是主要模态。模态1的方差贡献率达到了81.01%,主要反映了台风期间的潮流的信息。模态2的方差贡献率为6.27%,主要反映了流场的散度信息。模态3的方差贡献率为2.22%,主要反映了流场的旋度信息。
[Abstract]:High frequency ground wave radar (HF ground wave radar) is a marine remote sensing equipment which has been developed to monitor the dynamic parameters of ocean surface in the past 40 years. By using the first order scattering and two order scattering mechanism of the high frequency electromagnetic wave on the ocean surface, it can extract the flow field, the wind field, the wave field and so on from the radar echo, so as to achieve a large range of ocean environment. The real-time monitoring of precision and all-weather is a necessary supplement to the existing marine remote sensing equipment and remote sensing means. It is considered to be one of the cheapest and effective marine environmental monitoring means in the exclusive economic zone. The ocean current observed by high frequency ground wave radar is a flat average current of a certain depth of the ocean surface. The accuracy of the observation results of the high frequency ground wave radar has been proved. The current high frequency ground wave radar current observation has reached the operational level and may play an important role in the various functional departments of the country.
The study of high frequency ground wave radar used for monitoring marine environment began in 1987. Under the support of "95", "fifteen" and "11th Five-Year" National 863 program, the Wuhan University developed a mature OSMAR (Ocean State Monitoring and Analyzing Radar) series high frequency ground wave radar product. This article in 12th Five-Year "863 Plan" With the support of "Research on the distributed high frequency over the horizon radar detection and networking technology" in the marine field, the results of the OSMAR observed by the high frequency ground wave radar (HF) radar OSMAR, which are set up in the Zhoushan sea area of Zhejiang and the southwest sea of Taiwan Strait in Fujian, are studied. The main contents are as follows:
1) through the quasi harmonic analysis of the sea current data obtained during the comparison and verification of the two high frequency ground wave radar stations distributed in the Zhujiajian of Zhoushan archipelago in Zhejiang and Shengshan in August 2005, the spatial distribution characteristics of the surface tidal currents in the outer sea of Zhoushan based on full coverage observation are given for the first time. The results of the analysis show that the outer sea of Zhoushan is in the outer sea. Tidal currents belong to the regular semidiurnal tide, and the influence of the shallow water tide is larger. The form of the tidal current movement is dominated by the previous reflow. The maximum possible velocity distribution is gradually weakened from the northeast direction. The residual current in the near shore is larger than the far coast during the experimental period, and the direction is basically north to the East, and with the increase of the distance from the north to the East, the direction is gradually increasing. The distribution of water depth affects the distribution of shallow water tide, the distribution of tidal current, the distribution of maximum possible velocity, the distribution of residual current and so on.
2) through the quasi harmonic analysis of the 3 day vector sea currents observed in the Dongshan and Longhai high frequency ground wave radar stations in Fujian Province, the spatial distribution characteristics of the surface tidal currents in the southwestern sea area of the Taiwan Strait are studied. The analysis results show that the characteristics of the tidal current in this sea area are dominated by the regular semidiurnal tidal current. The main axis of the flow ellipse is parallel to the coastline. The maximum possible velocity increases gradually from the northeast to the southwest and is basically consistent with the trend of the measured maximum current. The residual current is mainly in the northeast direction influenced by the Taiwan Strait warm current. The topography also has a great influence on the spatial distribution of the tidal current.
3) the harmonic analysis method is used to analyze the results of the high frequency ground wave radar current of 2 months. The space-time distribution characteristics of the tidal current in the southwestern sea area of Fujian Taiwan Strait are given. The harmonic analysis results of the single point current sequence are given, and the spatial distribution characteristics of the M2 tidal current ellipse, the maximum flow velocity and the residual current are analyzed. The trend of the tidal current in this area is dominated by the regular semidiurnal tide, and the M2 tidal current ellipse is NE-SW in the direction of the tidal current ellipse near the coastline, which is basically the same as the axis of the Taiwan Strait. The trend of the tidal current ellipse far away from the coast line is slowly changing to the N-S, and the form of the tidal movement is dominated by the previous reflux. The maximum velocity distribution is subject to the strong northeast monsoon. It has a larger change range, especially in Taiwan shoals. The maximum flow rate reaches 150cm/s. residual current, which is also influenced by the northeastern monsoon, and its direction is basically directed to the southwest.
4) the analysis of the response process of the surface sea current to the typhoon during the typhoon of the lion mountain shows that the first order peak of the Doppler spectrum of the high frequency ground wave radar echo is obviously broadened by the lion mountain typhoon, and the oscillation period of the first order peak broadens from the semidiurnal tide period to the whole daily tide period. The signal to noise ratio of the echo of the eighth distance element is about 2- The maximum velocity of flow in the South and northeast of the 10dB. observational sea area is up to 100cm/s, and the typhoon path of the lion mountain is almost symmetrical. The increase of the typhoon track on the right is slightly greater than that on the left side. The rotation and divergence of the flow field in the observed sea area during the typhoon are all greatly increased, and the maximum increase is almost doubled. The value of curl is much lower than that before typhoons. After 2.5 days, the typhoon gradually returns to its normal level.
5) the vector orthogonal empirical function analysis is used to analyze the current data of the two radar stations in the east mountain of the Fujian demonstration area of the high frequency ground wave radar and the two radar stations in the Fujian demonstration area. The analysis results show that the variance contribution rate of the first three modes is 91%, 4% and 1.4% respectively, and the cumulative variance contribution rate is 96%, which is the main mode. The space time distribution characteristic table of modal 1 The Ming mode 1 mainly reflects the information of the half day flow and reflects the information of the depth distribution to a certain extent. The space time distribution characteristics of modal 2 show that the mode 2 mainly reflects the information of the wind flow and the rotational characteristics of the flow field; the mode 3's space time distribution characteristic indicates that the mode 3 mainly reflects the information of the upwelling.
6) the data of the lion mountain typhoon period (August 30, 2010 -2014 September 4th) were analyzed by ComplexEOF. The analysis results showed that the variance contribution rate of the first three modes reached 89.51%, and the main mode was the variance contribution rate of modal 1, which mainly reflected the information of the tidal current during the typhoon. The variance contribution rate of modal 2 was 6.27%. The variance contribution rate of modal 3 is 2.22%, which mainly reflects the curl information of the flow field.
【学位授予单位】：武汉大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN958.93

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