| 变分方法在渤海海域ASCAT风场订正中的应用 |
| |
| 引用本文： | 郭玉娣,刘彬贤,梁冬坡.变分方法在渤海海域ASCAT风场订正中的应用[J].应用气象学报,2019,30(3):376-384. |
| |
| 作者姓名： | 郭玉娣 刘彬贤 梁冬坡 |
| |
| 作者单位： | 天津海洋中心气象台, 天津 300074 |
| |
| 基金项目： | 环渤海区域科技协同创新基金项目（QYXM201712） |
| |
| 摘 要： | 利用渤海观测站风场对ASCAT风场进行检验，发现其风速、风向均有较大误差，尤其在渤海中部以外的海域可信度相对较低。为提高ASCAT风场在渤海海域的精度，基于变分方法，利用渤海观测站风场对2017年9月—2018年2月的ASCAT风场进行订正，得到空间分辨率为12.5 km×12.5 km的订正风场。并对辽东湾、渤海湾、莱州湾、渤海中部和渤海海峡5个海域风场的订正误差进行检验，结果表明:ASCAT风场订正后精度提高显著，风速平均偏差从4 m·s-1减小为1 m·s-1，风向平均偏差从-30°~30°减小为-7°~4°，可见变分方法对渤海ASCAT风场有很好的订正效果，尤其对误差较大的渤海湾订正效果最为明显。对2017年12月18日的一次大风过程进行订正分析，结果表明:订正风场可以很好地反映沿岸风场信息和大风过程中的风速极值区，并能动态监测大风变化过程。变分方法解决了海面观测数据空间分辨率低、ASCAT数据精度低的问题，能够实时监测海上大风，且对大风预报有很好的指导意义，能够为海洋模式提供更精确的初始场。
|
| 关 键 词： | 变分方法 渤海 ASCAT 检验与应用 |
| 收稿时间： | 2018/8/21 0:00:00 |
| 修稿时间： | 2019/1/17 0:00:00 |
Application of Variational Method to Correction of ASCAT Wind Field in the Bohai Sea |
| |
| Guo Yudi,Liu Binxian and Liang Dongpo.Application of Variational Method to Correction of ASCAT Wind Field in the Bohai Sea[J].Quarterly Journal of Applied Meteorology,2019,30(3):376-384. |
| |
| Authors: | Guo Yudi Liu Binxian and Liang Dongpo |
| |
| Affiliation: | Tianjin Marine Meteorological Center, Tianjin 300074 |
| |
| Abstract: | It is found that the wind velocity and wind direction of ASCAT have large errors comparing with observations of the Bohai Sea stations. Error analysis results show that the mean wind velocity deviations of ASCAT of the Bohai Bay, Bohai Strait, Laizhou Bay, Central Bohai Sea and Liaodong Bay areas are from the largest to the smallest. The mean wind direction deviation of ASCAT of the Laizhou Bay, Bohai Bay, Liaodong Bay, Bohai Strait and Central Bohai Sea area are from the largest to the smallest. The wind speed deviation of the Bohai Bay is the largest, and the wind direction deviation of the Laizhou Bay is the largest. According to error analysis results, the reliability of ASCAT wind field in the Bohai Sea needs to be improved. Therefore, the wind field of ASCAT is corrected using observations of the Bohai Sea stations in terms of variational method, which can obtain the corrected wind field with spatial resolution of 12.5 km×12.5 km and temporal resolution of 12 hours. In addition, to test the applicability of variational method in the sea area, the corrected wind field in five sea areas including the Liaodong Bay, Bohai Bay, Laizhou Bay, Central Bohai Sea and Bohai Strait are verified. Verification results show that the accuracy of ASCAT wind field is improved significantly after correction, the average deviation of wind velocity is reduced from 4 m·s-1 to 1 m·s-1, and the average deviation of wind direction is reduced from-30 °-30 ° to -7 °-4 °. The variational method is proved effective on ASCAT wind field correction. The ASCAT wind field revised by variational method from September 2017 to February 2018 shows that the distribution of the wind field is consistent with the wind field observed on the sea surface. The corrected wind speed of the Bohai Sea is proportional to the offshore distance and contour depth, which means areas further offshore, with deeper depth contour and wider surface are likely less influenced by submarine topography and the friction coefficient, and therefore the wind speed value is greater, and the wind direction is from the north to the northwest. The analysis of a gale process on 18 December 2017 shows that the corrected wind field can reflect coastal wind field information and the extreme value area of wind velocity in the process of wind, and it can monitor the process of gale changes dynamically. The variational method solves the problem of low spatial resolution of stations and low accuracy of ASCAT. It also has a good guiding significance for gale forecasting and can provide more accurate initial field for ocean models. |
| |
| Keywords: | variational method the Bohai Sea ASCAT inspection and application |
| 本文献已被 CNKI 等数据库收录！ |
| 点击此处可从《应用气象学报》浏览原始摘要信息 |
|
点击此处可从《应用气象学报》下载全文 |
|
