Comparison of directional wave spectrum hindcast to the buoy data measured near the typhoon path

Transcription

1 Comparison of directional wave spectrum hindcast to the buoy data measured near the typhoon path TAERIM KIM and JAEHYUK LEE Department of Ocean Science and Engineering Kunsan National University, Republic of Korea 1 st International Workshop on Waves, Storm Surges and Coastal Hazard Liverpool, UK, 1-15, September 217

2 Contents Background Wind data and wave model Wave directional spectrum analysis Comparison of model results Summary and next steps

3 Background(1) 1. Typhoon Bolaven(1215)(TYB_category 3) generated record breaking waves and damaged several ports severely. The central pressure and maximum wind velocity reached up to 91h and 51.8 m/s, respectively. It is the most powerful typhoon which passed the Yellow Sea with casualties of 15 and property damages of over 7 million dollars.

4 Typhoon Bolaven Path and Satellite Images TYB Path Satellite Images(COMS) NTC / KMA (National Typhoon Center / Korea Meteorological Administration)

5 Typhoon Bolaven Wind & Wave IEODO Ocean Station data for 1 years. Hs =1.75 m Wind velocity= m/sec Significant Wave Height (m) Ieodo ( 26 ~ 216 ) 212/8/29 6: Hs : 1.75 m Year ( 26 ~ 216 ) 5 Wind Speed (m/s) /8/27 19: m/s Year ( 26 ~ 216 )

6 Damages by Typhoon Bolaven

7 Damages by Typhoon Bolaven

8 Damages by Typhoon Bolaven

9 Storm Surge by Typhoon Bolaven?

10 Background(2) 1. Typhoon Bolaven(1215)(TYB_category 3) generated record breaking waves and damaged several ports severely. The central pressure and maximum wind velocity reached up to 91h and 51.8 m/s, respectively. It is the most powerful typhoon which passed the Yellow Sea with casualties of 15 and property damages of over 7 million dollars. 2. TYB generated extreme waves (Hmax=2.7m) and also high waves for long duration. The reason of this extreme case is considered by dynamic fetch effect but needs to be analyzed with more data.

11 Latitude (degree) Typhoon Bolaven Characteristics ( 1 ) Longitude (degree) WUKONG ( ~ 8.19) SHANSHAN ( ~ 9.19) MAN-YI ( ~ 7.17) USAGI ( ~ 8.4) NARI ( ~ 9.17) KALMAEGI ( ~ 7.2) DIANMU ( ~ 8.12) KOMPASU ( ~ 9.3) MALOU ( ~ 9.8) MEARI ( ~ 6.27) MUIFA ( ~ 8.9) TALAS ( ~ 9.5) KHANUN ( ~ 7.19) DAMREY ( ~ 8.3) TEMBIN ( ~ 8.31) BOLAVEN ( ~ 8.29) SANBA ( ~ 9.18) LEEPI ( ~ 6.21) KONG-REY ( ~ 8.31) DANAS ( ~ 1.9) NEOGURI ( ~ 7.11) HALONG ( ~ 8.11) NAKRI ( ~ 8.3) VONGFONG ( ~ 1.14) CHAN-HOM ( ~ 7.13) NANGKA ( ~ 7.18) HALOLA ( ~ 7.27) GONI ( ~ 8.24) Central Pressure (hpa) Maximum Wind Speed (m/s) Radius of Strong Wind (km) Latitude (degree) Latitude (degree) Latitude (degree)

12 Typhoon Bolaven Wind & Wave IEODO Ocean Station data for 1 years. Hs =1.75 m Wind velocity= m/sec Significant Wave Height (m) Ieodo ( 26 ~ 216 ) 212/8/29 6: Hs : 1.75 m Year ( 26 ~ 216 ) 5 Wind Speed (m/s) /8/27 19: m/s Year ( 26 ~ 216 )

13 Background(3) 1. Typhoon Bolaven(1215)(TYB_category 3) generated record breaking waves and damaged several ports severely. The central pressure and maximum wind velocity reached up to 91h and 51.8 m/s, respectively. It is the most powerful typhoon which passed the Yellow Sea with casualties of 15 and property damages of over 7 million dollars. 2. TYB generated extreme waves (Hmax=2.7m) and also high waves for long duration. The reason of this extreme case is considered by dynamic fetch effect but needs to be analyzed with more data. 3. Typhoon wind and wave fields are very complicate and good example to check the model performance. The numerical wave prediction model needs to be tested with more wave data, specially in terms of directional spectrum.

14 Wave Observation Sites Wave Directional Spectrum - KOGA-S1(33.4 km) - KOGA-S4(16.6 km) - IEODO Significant Wave Height - Chilbaldo - Seocheon - Gadaeam

15 WAVEWATCH3(Depth and Grids) - WAVEWATCH3 ( v 4.18 ) CHINA KOREA JAPAN - Modeling area latitude 18 N~52.5 N, longitude 115 E~147 E - Grid information Unstructured Grid Nodes : 121,292 Elements : 214,597 - Grid resolution Max : 2 km Min : 1 m - Spherical coordinate - Depth Data : ETOPO1

16 KMA UM Wind Data Global(UM) ASIA(WRF) ASIA(UM) KOREA(UM) - KMA UM(Unified Model) Wind Data RDAPS(Regional Data Assimilation and Prediction System) Spatial Resolution : 12 km (.11 ), 419 x 491 grids. Temporal Resolution : 3 hour, 4 times/day(, 6, 12, 18UTC), 72 hour prediction - WW3 Wind Data - 1m Sea Wind Data( U, V ), 6 hour Resolution

17 UM Wind Field Data(RDAPS)

18 Comparison of UM Wind with Observation Data Observed 4 Ieodo Ieodo Unified Model W Observed Unified Model Wind Speed (m/s) Wind Direction S E N 8/23 8/25 8/27 8/29 Month/Day (212) 8/23 8/25 8/27 8/29 Month/Day (212) Chilbaldo Observed Unified Model W Chilbaldo Observed Unified Model Wind Speed (m/s) Wind Direction S E N 8/23 8/25 8/27 8/29 8/23 8/25 8/27 8/29 Month/Day (212) Month/Day (212) Gadaeam Observed Unified Model W Gadaeam Observed Unified Model Wind Speed (m/s) Wind Direction S E N 8/23 8/25 8/27 8/29 8/23 8/25 8/27 8/29 Month/Day (212) Month/Day (212) Seocheon Observed Unified Model W Seocheon Observed Unified Model Wind Speed (m/s) Wind Direction S E N

19 ASCAT Wind Fields(Eumersat MetOp-A) morning passes (~9:3 local time), evening passes (~21:3 local time) 9:54 (KST), 21:6 (KST) 27 th August 212

20 ASCAT Wind vs UM Wind 212/8/27 9:54-212/8/27-21:6

21 Wave Fields Simulation ( 1 ) WW3 ( RDAPS/UM ) - High waves are generated on the right side of the TYB translation direction. - From 27 th to 28 th in August 212, higher than 1 m Hs was generated along the TYB track.

22 Comparison of WW3 with Observation Significant Wave Height (m) 2 Observed KOGA-S1 WAVEWATCH3(UM) /23 8/25 8/27 8/29 Month / Day (212) Significant Wave Height (m) 2 Observed KOGA-S4 WAVEWATCH3(UM) /23 8/25 8/27 8/29 Month / Day (212) 1 15 Ieodo Observed WAVEWATCH3(UM) 8 Chilbaldo Observed WAVEWATCH3(UM) Significant Wave Height (m) 1 5 8/23 8/25 8/27 8/29 Significant Wave Height (m) /23 8/25 8/27 8/29 Month / Day (212) Month / Day (212) 6 5 Seocheon Observed WAVEWATCH3(UM) 8 Gadaeam Observed WAVEWATCH3(UM) Significant Wave Height (m) /23 8/25 8/27 8/29 Month / Day (212) Significant Wave Height (m) /23 8/25 8/27 8/29 Month / Day (212)

23 Review of Typhoon Wind and Wave Fields Typical typhoon wind field in the Northern Hemisphere (Young, 26, JGR) Spatial structure of directional wave spectra in hurricanes (Esquivel-Trava et al., 215, Ocean Dynamics)

24 Wave Directional Spectrum Changes(Observed) KOGA-S1 N N N N 27 N Y / R X / R KOGA-S4 KOGA-S4 N N N N 27 N Y / R X / R

25 Y / R KOGA-S1 Wave Directional Spectrum Changes X / R KOGA-S4 Y / R X / R

26 Comparison of Directional Spectrum(WW3 vs S1) KOGA-S1 N N N N 27 N Y / R X / R KOGA-S1 wavewatch

27 Comparison of Directional Spectrum(WW3 vs S4) Y / R KOGA-S4 N N N N 27 N X / R KOGA-S4 wavewatch3

28 Summary and Next Steps(1) 1. Up to now, directional wave spectrum data observed at two buoys near the TYB path clearly do not show the dynamic fetch effects. Need more analysis using normalization in terms of TYB speed, Cg, Rmax, relative location from the TYB center and wave growth

29 needed for comparison to buoy data. Summary and Next Steps(2) 2. Comparison of WW3 and observed data shows reasonably good agreement in time series of Hs. Underestimation of Hs near the TYB path seems to be originated from underestimation of UM wind. 3. The calculated directional spectrum is similar to buoy data near the TYB center but shows differences at far point from the center 4. Same analysis of model results using normalization is

30 2 THANK YOU!! Questions & Comments