• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2004.05a
• /
• pp.229-234
• /
• 2004

A Typhoon wave is generated by wind fields during the Passage of Typhoon. Transporting wind field makes wind wave and swell in the open sea, and then, those wave components are transported in the shallow water. Typhoon waves in the shallow water is generated by Typhoon wind field and incident wave. Bisides, Incident waves to the shallow water are deformated by topographic conditions. This paper estimated the analysis of the Typhoon waves by wind fields and incident waves according to wave action balance equation model. As the result of wave numerical experiment, wave field during the passage of Typhoon 'Memi' in the shallow water is strongly effect by wind fields. Wave action balance equaion can be partially used for Typhoon wave simulations.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2006.05a
• /
• pp.567-573
• /
• 2006

An efficient typhoon wave-generating model is applied to northeast Asia sea zone presented that can be used by civil defense agencies for real-time prediction and fast warnings on typhoon-generated wind wave and storm surge. Instead of using commercialized wave models such as WAM, SWAN, the wind waves are simulated by using a new concept of wavelength modulation to enhance broader application of the hyperbolic wave model of the mild-slope equation type. The results simulated along the Korean coasts during Typhoon Nabi (2005) showed reasonable agreement with the recorded wind waves.

• Journal of Ocean Engineering and Technology
• /
• v.26 no.1
• /
• pp.47-53
• /
• 2012

A coastal flood area was predicted using the empirical superposition of the typhoon surge level and typhoon wave height along the Busan coastal area. The historical typhoon damages were reviewed, and the coastal topography was measured using VRS-GPS. A FEMA formula was applied to estimate the coastal flood area in a typhoon case when the measured and predicted data of typhoon waves are not available. The results in the area of Haeundae beach and Gwangalli beach were verified using the flood area data from the case of Typhoon Maemi (2003). If a Hurricane Katrina class typhoon were to pass through the Maemi trajectory, the areathat would be flooded along theBusan coastal area was predicted and compared with the results of the Maemi case. Because of the lack of ocean environment data such as data for the sea level, waves, bathymetry, wind, pressure, etc., it is hard to improve the prediction accuracy for the coastal flood area in the typhoon case, which could be reflected in the policy to mitigate a typhoon's impact. This paper discusses the kinds of ocean environment information that is needed to predict a typhoon's impact with better accuracy.

• Journal of Ocean Engineering and Technology
• /
• v.19 no.6 s.67
• /
• pp.22-28
• /
• 2005

We investigated the characteristics of the overflow/wave overtopping, induced by the storm surge and high waves in Masan bay and Busan Coast during Typhoon 'Maemi', which landed at the southeast coast of the Korean peninsula on September, of 2003, causing a severe inundation disaster. Characteristics of the water level, increase by the overflow / wave overtopping, were discussed in two patterns. One is the increase of water level in the region, located inside of a bay, like Masan fishing port, and the waves are relatively small. The other is in the open sea, in which the waves act directly, as on the seawall in Suyong bay. In the former region, the water level increase was affected by the storm surge, as well as the long period oscillation and waves. In Masan fishing port, about $80\%$ of the water level increase on the quay wall was caused by the storm surge. In the latter one, it was greatly affected by the wave run-up. In Suyong bay, about $90\%$ of the water level increase on the seawall was caused by the wave run-up.

• Journal of Ocean Engineering and Technology
• /
• v.21 no.1 s.74
• /
• pp.1-6
• /
• 2007

While a typhoon is traveling, characteristics of its wind fields are continuously changing, producing severe changes in local water level and wave conditions, especially, when a typhoon comes into shallow water. However, there have not been many studies related to local typhoon effects, especially, considering real time changes of wind direction related to the coastal topography. In the study, the characteristics of the wind field by typhoon and topographical characteristics in shallow water are considered, as well as conditions of wave climate estimation. These are performed by the SWAN (Simulating waves nearshore) model, in order to estimate the growth of wave energy due to the wind field. It can be strongly suggested that the wave energy of theof an inner bay should be estimated when the direction of the bay entrance and the wind direction of the typhoon are identical. The result of the numerical calculations is in better agreement with the observed data than the result of the conventional estimation techniques.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.48 no.3
• /
• pp.227-234
• /
• 2012

This paper describes the remote monitoring of breaking ocean waves generated by Typhoon Nabi, whose name means butterfly in Korean, using a marine X-band radar in the Yongho Man, Busan, Korea. The basic purpose of this study is to investigate the dynamic behavior and to estimate the periods of breaking waves across the surf zone from radar image sequences. In these experiments, the land-based radar system imaged the inshore zone of three miles from the coastline to a isobath of 30 meters. The wave period and the dominant wave direction for breaking ocean waves extracted directly from radar image sequences were 157.4 meters and 298 degrees, respectively. However, the result calculated quantitatively by the continuous wavelet transform (CWT) showed that the period of breaking waves was 154.3 meters. The average difference in breaking wave periods between the value extracted by using EBRL (electronic bearing and range line) of radar and the calculated value by CWT was 3.1 meters, showing that the CWT method is also accurate. These results suggest that a marine X-band radar system is a viable method of monitoring the breaking ocean waves.

• Journal of the Korean Institute of Navigation
• /
• v.13 no.3
• /
• pp.45-65
• /
• 1989

Various typhoon data near Yongil Bay, Korea from 1961 to 1985 were collected with some critria and analyzed with the help of the computer. Introducing the pressure profile models and predicting the typhoon wind and wave fields, the 100-year design wave parameters were calculated. Additionally, the wave data at the southeast coast of Korea were statistically analyzed. The deep water wave climate of this bay indicated that Typhoon Brenda, 1985 had wave characteristics of 100-year return period, Typhoon model and storm surge model studies were made for this typhoon. These, including other design parameters, were introduced into the calculation of total design water depth.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.18 no.4
• /
• pp.294-300
• /
• 2006

Implicit numerical scheme using fractional step method and FCT is used to improve the computational efficiency of WAM. Square wave test and simulation of typhoon generated waves are conducted to verify the numerical scheme. The applied scheme shows much less numerical diffusion and due to the implicit character of the scheme much larger time steps can be used without numerical instability. For typhoon MAEMI, comparison between the numerical results and the measured data shows good agreement.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.35 no.4
• /
• pp.67-74
• /
• 2023

High waves and storm surges due to tropical cyclones cause great damage in coastal areas; therefore, accurately predicting storm surges and high waves before a typhoon strike is crucial. Meteorological forcing is an important factor for predicting these catastrophic events. This study presents an improved methodology for determining accurate meteorological forcing. Typhoon Chaba, which caused serious damage to the south coast of South Korea in 2016, was selected as a case study. In this study, symmetric and asymmetric parametric vortex models based on the typhoon track forecasted by the Model for Prediction Across Scales (MPAS) were used to create meteorological forcing and were compared with those models based on the best track. The meteorological fields were also created by blending the meteorological field from the symmetric / asymmetric parametric vortex models based on the MPAS-forecasted typhoon track and the meteorological field generated by the forecasting model (MPAS). This meteorological forcing data was then used given to two-way coupled tide-surge-wave models: Advanced CIRCulation (ADCIRC) and Simulating Waves Nearshore (SWAN). The modeled storm surges and waves correlated well with the observations and were comparable to those predicted using the best track. Based on our analysis, we propose using the parametric model with the MPAS-forecasted track, the meteorological field from the same forecasting model, and blending them to improve storm surge and wave prediction.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.21 no.1
• /
• pp.79-90
• /
• 2009

This paper presents the development of dynamically combined Typhoon generated surge-tide-wave numerical model which is applicable from deep to shallow water. The dynamically coupled model consists of hydrodynamic module and wind wave module. The hydrodynamic module is modified from POM and wind wave module is modified from WAM to be applicable from deep to shallow water. Hydrodynamic module computes tidal currents, sea surface elevations and storm surges and provide these information to wind wave module. Wind wave mudule computes wind waves and provides computed information such as radiation stress, sea surface roughness and shear stress due to winds. The newly developed model was applied to compute the surge, tide and wave fields by typhoon Maemi. Verification of model performance was made by comparison of measured waves and tide data with simulated results.