36th International Conference on Coastal Engineering

K. N. Toosi University of Technology

Waseda University

Tehran University NUMERICAL SIMULATION OF TROPICAL AND STORM SURGES IN THE ARABIANSEA Mohsen Soltanpour, K. N. Toosi University of Technology Zahra Ranji, K. N. Toosi University of Technology Tomoya Shibayama, Waseda University Sarmad Ghader, University of Tehran Shinsaku Nishizaki, Waseda University Study Area

Motivation

Numerical Simulation

Conclusion

1/19 20 Cyclones and Depressions Study Area

15 Motivation 10

Numerical

5 Simulation Frequency of occurence (percent) ofoccurence Frequency 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Conclusion

30 Sever Cyclonic Storms

25

20 2/19

15

10

5

Frequency of occurence (percent) ofoccurence Frequency 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Target Study Area

Motivation Gonu, 2007 Cyclones Ashobaa, 2015 Numerical Simulation

Conclusion

3/19 Study Area Field Measurements (Gonu) Motivation Bay

Numerical Simulation

Conclusion

4/19 Study Area

Motivation

Numerical More severe Simulation cyclonic storms since 2000 Conclusion

6/19

Time History of Maximum Wind Speed during Modelling Study Area Atmosphere Framework Model (WRF) Motivation

Numerical Simulation WAVE Model Current vector Ocean Circulation Conclusion (SWAN, SWAVE) Radiation Stress Model (FVCOM)

Boundary Boundary condition condition 7/19 Global Global Wave Model Tide Model (WWIII) (TPXO 8) Study Area

Motivation

Numerical WRF domain Simulation

Conclusion

8/19 FVCOM, SWAVE, SWAN domain WRF Model Study Area Model component ConfigurationAshobaa (2015) Gonu (2007) Model version 3.9.1 Motivation Start time June 6th-00 UTC June 2nd-00 UTC Numerical Initial and boundary condition FNL (1°) GFS ANL (0.5°) Simulation Nesting type Fixed nest Conclusion Vertical resolution 40 terrain following sigma mass coordinate 30 km: 62.5 E-17.5 N (210×180) Horizontal resolution and domains 10 km: 58.31 E-19.03 N (517×277) Planetary 9/19 Target Microphysics Cumulus Land surface Surface Radiation boundary cyclones scheme scheme scheme layer scheme scheme layer scheme Ashobaa Grell 3D Unified Noah WSM3 (2015) Ensemble Land Surface MM5 Dudhia & YSU Gonu 5–layer Thermal Similarity RRTM WSM6 Kain–Fritsch (2007) Diffusion TCs Track Study Area

Gonu, 2007 Ashobaa, 2015 Motivation

Numerical Simulation

Conclusion

10/19 Study Area

Motivation

Numerical Simulation

Conclusion TCs

Center 19

/ 11 WRF Model Results Model WRF Measurement Stations Measurement Wave Models Study Area Wave Model ConfigurationSWAVE SWAN Motivation Horizontal grid 1-50 km unstructured grid 1-50 km unstructured grid Bathymetry GEBCO 30 sec + local ETOPO 1 min + local Numerical Simulation Wind field WRF WRF

Wave-wave interaction Triad and quadruplet Triad and quadruplet Conclusion White capping Komen Alves & Banner Wave growth Komen WESTH 12/19 Wave breaking 0.73 0.73 Bed friction Madsen Madsen Frequency Resolution 40 40 Directional Resolution 24 72 Boundary condition - WWIII SWAN Model Study Area

Results Motivation

Numerical Simulation

Conclusion

13/19 Circulation Model Study Area ConfigurationFVCOM Motivation

Horizontal grid 100-50000 m unstructured grid Numerical Vertical grid 10 sigma layers Simulation Time step 2 sec Bathymetry GEBCO 30 sec + local Conclusion Open boundary TPXO 8 Wind field WRF Pressure field WRF 14/19 Vertical turbulence M.Y 2.5 Closure model Horizontal turbulence Smagorinsky Bed roughness z0 = 0.005 Study Area FVCOM Model Motivation

Numerical Results-Gonu Simulation

Conclusion

15/19 FVCOM Model Results- Ashobaa Fully Coupled FVCOM-SWAVE Study Area

Results Motivation

Numerical Simulation

Conclusion

16/19 Study Area

Motivation

Numerical Simulation

Conclusion

17/19 Summary Study Area

Motivation . Cyclone Gonu, which occurred from June 1 to June 7, 2007, was the most intense on record in the . Numerical Simulation . Cyclone Ashobaa, 2015 is the last cyclone reach to the Gulf of .

. Analysis of historical data indicates the possibility of more frequent intense Conclusion cyclones in future. . A coupled system of WRF-FVCOM-SWAN was employed and calibrated for the simulations of winds, waves and surges, resulted from cyclones Gonu and 18/19 Ashobaa, as two examples of intense and weak target cyclones entered the . Conclusion Study Area

Motivation . Approaching cyclones towards the coastline, wind wave becomes predominant. Numerical . Two way coupling of wave-circulation models leads to insignificant change of Simulation surge height. . Cyclone landfall in the vicinity of the Gulf of Oman can cause significant positive Conclusion and negative surges in the enclosed basin of Persian Gulf.

. Surge height is strongly dependent on the bathymetry and shape of the bays, 19/19 besides the intensity of cyclone. Thank You For Your Attention