This study was performed to compare storm surges/tide simulated by the regional and coastal storm surges/tide forecast system （RTSM （regional tide/storm surges model）, CTSM （coastal tide/storm surges model）） usi...This study was performed to compare storm surges/tide simulated by the regional and coastal storm surges/tide forecast system （RTSM （regional tide/storm surges model）, CTSM （coastal tide/storm surges model）） using two different inputs from weather models （RDAPS （Regional Data Assimilation and Prediction System） and KWRF （Korea Weather and Research Forecasting）） during two typhoons that occurred between 2007 and 2008. Both the RDAPS and KWRF are the operational weather forecasting system in KMA （Korea Meteorological Administration）. The horizontal resolutions of RDAPS and KWRF are 30 and 10 km, respectively. The storm surges/tide was hind casted using sea wind and pressure fields of two Typhoons which was approaching Korean Peninsula. The CTSM using input from KWRF simulate very well the storm surges/tide pattern in the complex coastal areas. The result showed that the storm surges by the coastal storm surges/tide model with high resolution input was in well agreement with the observed sea level occurred by high tide and storm surges in the coastal areas.展开更多
Data from a long term measurement of Micro Rain Radar （MRR） at a mountain site （Daegwallyeong, DG, one year period of 2005） and a coastal site （Haenam, HN, three years 2004-2006） in South Korea were analyzed to ...Data from a long term measurement of Micro Rain Radar （MRR） at a mountain site （Daegwallyeong, DG, one year period of 2005） and a coastal site （Haenam, HN, three years 2004-2006） in South Korea were analyzed to compare the MRR measured bright band characteristics of stratiform precipitation at the two sites. On average, the bright band was somewhat thicker and the sharpness （average gradient of reflectivity above and below the reflectivity peak） was slightly weaker at DG, compared to those values at HN. The peak reflectivity itself was twice as strong and the relative location of the peak reflectivity within the bright band was higher at HN than at DG. Importantly, the variability of these values was much larger at HN than at DG. The key parameter to cause these differences is suggested to be the difference of the snow particle densities at the two sites, which is related to the degree of riming. Therefore, it is speculated that the cloud microphysical processes at HN may have varied significantly from un-rimed snow growth, producing low density snow particles, to the riming of higher density particles, while snow particle growth at DG was more consistently affected by the riming process, and therefore high density snow particles. Forced uplifting of cloudy air over the mountain area around DG might have resulted in an orographic supercooling effect that led to the enhanced riming of supercooled cloud drops.展开更多
A genetic algorithm was used to optimize the parameters of the two-dimensional Storm Surge/Tide Operational Model （STORM） to improve sea level predictions.The genetic algorithm was applied to nine typhoons that affe...A genetic algorithm was used to optimize the parameters of the two-dimensional Storm Surge/Tide Operational Model （STORM） to improve sea level predictions.The genetic algorithm was applied to nine typhoons that affected the Korean Peninsula during 2005-2007.The following model parameters were used：the bottom drag coefficient,the background horizontal diffusivity,Smagorinski＇s horizontal viscosity,and the sea level pressure scaling.Generally,the simulation results using the optimized,mean,and median parameter values improved sea level predictions.The four estimated parameters improved the sea level prediction by 76% and 54% in the bias and root mean square error for Typhoon Kalmaegi （0807） in 2008,respectively.One-month simulations of February and August 2008 were also improved using the estimated parameters.This study demonstrates that parameter optimization on STORM can improve sea level prediction.展开更多
文摘This study was performed to compare storm surges/tide simulated by the regional and coastal storm surges/tide forecast system （RTSM （regional tide/storm surges model）, CTSM （coastal tide/storm surges model）） using two different inputs from weather models （RDAPS （Regional Data Assimilation and Prediction System） and KWRF （Korea Weather and Research Forecasting）） during two typhoons that occurred between 2007 and 2008. Both the RDAPS and KWRF are the operational weather forecasting system in KMA （Korea Meteorological Administration）. The horizontal resolutions of RDAPS and KWRF are 30 and 10 km, respectively. The storm surges/tide was hind casted using sea wind and pressure fields of two Typhoons which was approaching Korean Peninsula. The CTSM using input from KWRF simulate very well the storm surges/tide pattern in the complex coastal areas. The result showed that the storm surges by the coastal storm surges/tide model with high resolution input was in well agreement with the observed sea level occurred by high tide and storm surges in the coastal areas.
基金funded by the Korean Meteorological Administration Research and Development Program under Grant CATER 2006-2307.
文摘Data from a long term measurement of Micro Rain Radar （MRR） at a mountain site （Daegwallyeong, DG, one year period of 2005） and a coastal site （Haenam, HN, three years 2004-2006） in South Korea were analyzed to compare the MRR measured bright band characteristics of stratiform precipitation at the two sites. On average, the bright band was somewhat thicker and the sharpness （average gradient of reflectivity above and below the reflectivity peak） was slightly weaker at DG, compared to those values at HN. The peak reflectivity itself was twice as strong and the relative location of the peak reflectivity within the bright band was higher at HN than at DG. Importantly, the variability of these values was much larger at HN than at DG. The key parameter to cause these differences is suggested to be the difference of the snow particle densities at the two sites, which is related to the degree of riming. Therefore, it is speculated that the cloud microphysical processes at HN may have varied significantly from un-rimed snow growth, producing low density snow particles, to the riming of higher density particles, while snow particle growth at DG was more consistently affected by the riming process, and therefore high density snow particles. Forced uplifting of cloudy air over the mountain area around DG might have resulted in an orographic supercooling effect that led to the enhanced riming of supercooled cloud drops.
基金supported by the National Institute of Meteorological Research of the Korea Meteorological Administration
文摘A genetic algorithm was used to optimize the parameters of the two-dimensional Storm Surge/Tide Operational Model （STORM） to improve sea level predictions.The genetic algorithm was applied to nine typhoons that affected the Korean Peninsula during 2005-2007.The following model parameters were used：the bottom drag coefficient,the background horizontal diffusivity,Smagorinski＇s horizontal viscosity,and the sea level pressure scaling.Generally,the simulation results using the optimized,mean,and median parameter values improved sea level predictions.The four estimated parameters improved the sea level prediction by 76% and 54% in the bias and root mean square error for Typhoon Kalmaegi （0807） in 2008,respectively.One-month simulations of February and August 2008 were also improved using the estimated parameters.This study demonstrates that parameter optimization on STORM can improve sea level prediction.
