
基于海气耦合模式的超强台风“山竹”数值模拟
Numerical investigation of the super typhoon Mangkhut based on the coupled air-sea model
基于中尺度大气模式WRF和区域海洋模式ROMS,构建WRF-ROMS海气双向耦合模式,针对2018年超强台风“山竹”进行模拟。利用观测数据对台风路径和强度进行验证,结果表明海气耦合模式对台风“山竹”的模拟相对单一模式有更高的精度,耦合模式得到的台风路径与最佳路径吻合良好,误差控制在60 km以内;获取的风速和海平面气压结果也较单一模式更为准确。基于海气耦合模拟结果,进一步分析台风作用下风场、气压场、海表流场和风暴增水的时空分布特征,结果表明:1)空间分布方面,台风进入南海后,七级风圈半径在台风沿路径右后方较大;气旋式流场与台风风场呈现出显著的埃克曼效应,流向与风向呈45°;风场、气压场、风生流场和增水分布均存在明显的不对称性,台风路径右侧的台风强度、流速和增水均大于左侧。2)时间分布方面,风场与气压场分布特征相似且与台风中心保持同步,流场和近岸风暴增水相对台风路径存在3 h左右的滞后。
Based on the mesoscale atmospheric model WRF and the regional ocean model ROMS, a two-way coupled WRF-ROMS air-sea model was constructed to simulate the super typhoon Mangkhut in 2018. The results showed that the simulation results of the coupled air-sea model were better than those of the only atmospheric or ocean model, and the error of the typhoon track obtained from the coupled model was within 60 km, which was in good agreement with the best track. Compared with the observation results, the simulation results of wind speed and sea level pressure in the coupled model were better than others model. Based on the simulation results of the coupled air-sea model, the spatial and temporal distribution of the wind field, pressure field, sea surface flow field, and storm surge under the super typhoon Mangkhut were further analyzed. The results showed that: (1) In terms of spatial distribution, after the typhoon entered the South China Sea, the radius of the seven-level wind circle was larger behind the right side of the typhoon; the cyclonic flow field showed a significant Ekman effect with the typhoon wind field, and the flow direction was 45° from the wind direction. The wind field, pressure field, wind-generated flow field and water gain distribution all had obvious asymmetry, and the typhoon intensity, flow velocity and water gain were greater on the right side of the typhoon path than on the left side. (2) In terms of time distribution, the distribution of the wind field and the pressure field were similar and synchronized with the typhoon center, while the wind-driven flow field and storm surge were three hours behind the typhoon track.
海气耦合模式 / 风暴潮 / 数值模拟 / 南海 / 台风“山竹”
coupled air-sea model / storm surge / numerical simulation / the South China Sea / super typhoon Mangkhut
[1] |
Extreme sea levels, caused by storm surges and high tides, can have devastating societal impacts. To effectively protect our coasts, global information on coastal flooding is needed. Here we present the first global reanalysis of storm surges and extreme sea levels (GTSR data set) based on hydrodynamic modelling. GTSR covers the entire world's coastline and consists of time series of tides and surges, and estimates of extreme sea levels. Validation shows that there is good agreement between modelled and observed sea levels, and that the performance of GTSR is similar to that of many regional hydrodynamic models. Due to the limited resolution of the meteorological forcing, extremes are slightly underestimated. This particularly affects tropical cyclones, which requires further research. We foresee applications in assessing flood risk and impacts of climate change. As a first application of GTSR, we estimate that 1.3% of the global population is exposed to a 1 in 100-year flood.
|
[2] |
|
[3] |
|
[4] |
段自强, 李永平, 于润玲, 等. 海洋飞沫方案改进对台风“威马逊”强度预报的影响[J]. 海洋与湖沼, 2016, 47(6):1075-1090.
|
[5] |
丁瑞, 朱良生. 条件变化对海口湾风暴增水的影响分析:以海鸥台风为例[J]. 海洋工程, 2018, 36(4):147-154.
|
[6] |
|
[7] |
|
[8] |
张浩键, 伍志元, 刘晓建, 等. 台风“天鸽”影响下珠江口水动力过程数值模拟研究[J]. 长沙理工大学学报:自然科学版, 2023, 20(4):142-152.
|
[9] |
|
[10] |
|
[11] |
叶芳, 刘磊, 马占宏, 等. 不同环境风场条件下冷尾流对台风强度的影响[J]. 热带气象学报, 2017, 33(3):368-374.
|
[12] |
|
[13] |
|
[14] |
A recent advance in the Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS) is described and used to study two-way air–sea coupling and its impact on two different weather scenarios. The first case examines the impact of a hurricane-induced cold ocean wake on simulated changes in the structure of Hurricane Katrina. The second case investigates the effect of wind- and current-induced island wakes and their impact on the local electromagnetic (EM) and acoustic propagation characteristics in the Southern California Bight region. In the Katrina case, both the atmosphere and ocean show a strong response from air–sea interaction. The model results show that wind-induced turbulent mixing, vertical advection, and horizontal advection are the three primary causes of the development of the trailing cold ocean wake. A distinct spatial separation is seen in these three primary forcing terms that are generating the bulk of the cooling in the ocean mixed layer. An asymmetric tropical cyclone structure change has been documented in detail from a more realistic, full physics, and tightly coupled model. These changes include a broadening of the eye, a reduced radius of hurricane-force wind, and a pronounced inner-core dry slot on the west side of the storm. In the island wake experiment, many finescale variations in the wind, current, and static stability structure resulting from the two-way interaction are described. These variations take the form of narrow vorticity and temperature anomalies that are found to reside in the ocean and atmosphere well downwind from the Channel Islands. Upwind differences in the lower-atmospheric wind and thermal structure also arise and are found to have a small impact on the lee-flow structure and EM characteristics of the southernmost Channel Islands.
|
[15] |
|
[16] |
蒋小平, 刘春霞, 齐义泉. 利用一个海气耦合模式对台风Krovanh的模拟[J]. 大气科学, 2009, 33(1):99-108.
|
[17] |
|
[18] |
伍志元, 蒋昌波, 邓斌, 等. 基于海气耦合模式的南中国海北部风暴潮模拟[J]. 科学通报, 2018, 63(33):3494-3504.
|
[19] |
|
[20] |
|
[21] |
|
[22] |
李心雨, 杨昀, 李自如, 等. WRF大气模式与台风经验模型在超强台风“山竹”过程重构中的比较分析[J]. 海洋工程, 2022, 40(4):53-64,111.
|
[23] |
陈晓斐, 齐琳琳, 何尽解, 等. 海洋垂直混合对中尺度海气浪耦合模式预报效果的敏感性试验[J]. 热带气象学报, 2018, 34(6):845-855.
|
[24] |
|
[25] |
于玲玲, 麦健华, 程正泉, 等. 热带气旋大风风圈半径非对称性特征及成因简析[J]. 气象学报, 2022, 80(6):896-908.
|
[26] |
|
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|
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