TY  - BOOK
AU  - Damlamian, Hervé
AU  - Krüger, Jens
ED  - Secretariat of the Pacific Community.
TI  - 2D coupled hydrodynamic spectral wave model of Rangiroa: the 1983 Orama-Nisha tropical cyclone
T2  - SPC SOPAC Technical report
U1  - 551.46309962 
PY  - 2013///
CY  - Suva, Fiji
PB  - SPC Applied Geoscience and Technology Division (SOPAC)
KW  - Ocean waves
KW  - French Polynesia
KW  - Cyclones
N1  - Également en français : "Modèle bidimensionnel couplé de Rangiroa (modèle hydrodynamique et modèle spectral de vague) - Cyclone tropical Orama-Nisha (1983)"
N2  - "As part of the EU-funded project Supporting Disaster Risk Reduction in Pacific Countries and Territories, the French Polynesia Government requested the Applied Geoscience and Technology Division (SOPAC) of the Secretariat of the Pacific Community (SPC) to investigate the impact of Cyclone Orama-Nisha (1983) on Rangiroa Atoll. Firstly, a MIKE21 numerical model coupling waves and currents was developed and calibrated against collected oceanographic data collected during a six-month field campaign (see companion report on oceanographic data acquisition). The weather conditions of Cyclone Orama-Nisha were then used to force the model. During cyclone Orama-Nisha, the model showed that a 5.8 m wave was generated on the ocean side in front of Avatoru. South of Rangiroa, a larger wave with Hs=8 m to 9 m was creating large setup on the southern reef, ranging from about 1.5 m to 2.0 m. The water level on the ocean off Avatoru generated by a combination of tide and atmospheric pressure reached 0.7 m. In the lagoon, the water level reached 1.7 m, above MSL, resulting from the influence of the tide, the wave pumping, the atmospheric pressure and the wind stress. At the peak of the cyclone, the wind blew at more than 26 m/s in the eastward direction over the lagoon, creating a large surface elevation gradient of about 80 cm, with a surface elevation of about 1.3 m on the western side and greater than 2.1 m on the eastern side. As the cyclone moved further south of Rangiroa the wind forcing decreased, but the model did not show any resulting seiche. However, the use of a constant radius of maximum speed (47 km) at each step of the cyclone resulted in a gentle and almost linear decrease of the wind forcing which prevented the seiche to take place. Finally, the peak condition of the cyclone around the populated area was extracted and used as boundary condition into an XBeach model to approximate the inundation that occurred during the event. The XBeach model showed that inundation only occurred in the lagoon, which is well in agreement with the one testimony we collected. The offshore wave field had a very limited impact on the populated islet."
ER  -