Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Oceanologia

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

WAVEWATCH-III source terms evaluation for optimizing hurricane wave modeling : A case study of Hurricane Ivan

Kalourazi Mehdi Yaghoobi, Siadatmousavi Seyed Mostafa, Yeganeh-Bakhtiary Abbas, Jose Felix

Oceanologia

2021

No. 63 (2)

194--213

Simulating hurricane-generated waves is a challenging task due to rapidly fluctuating wind speed and direction, simultaneous presence of swells propagating out of the previous location of the hurricane and following/opposing waves on either side of the hurricane track, and dissipation in wind speed radially from the center of the hurricane. Bulk wave parameters have been investigated using the source term packages ST3, ST4 and ST6 implemented in the WAVEWATCH-III model to determine the most appropriate formulation for simulating hurricane-generated waves in the Gulf of Mexico. Based on the comparisons between model results and in situ observations during the passage of Hurricane Ivan (2004), it is shown that ST3 is not as successful as other formulations for hurricane wave modeling. Calibrated ST6 variant, T12, has shown to be the best formulation for simulating bulk wave parameters at points within the range of hurricane wind forcing; however, for the area beyond, and also during fair weather conditions, calibrated ST4 formulation, T471-Ex4, is recommended. Although T471-EX4 and T12 packages outperformed other cases, they overestimated waves propagating in the oblique and opposing wind. Dependence of ST6 parameter a0 on wind and wave direction is examined to improve the model performance.

Simulating tropical storms in the Gulf of Mexico using analytical models

Kalourazi Mehdi Yaghoobi, Siadatmousavi Seyed Mostafa, Yeganeh-Bakhtiary Abbas, Jose Felix

Oceanologia

2020

No. 62 (2)

173--189

Different analytical models have been evaluated for estimating wind speed of the tropical storm, where the storm-induced wind velocity is calculated as a function of distance from the center of the hurricane. For these models, different parameters such as maximum wind speed, a radius of the maximum wind, hurricane shape parameter, hurricane translation speed and the orientation of the trajectory, etc., affect the shape of a hurricane. Hurricanes Lili (2002), Ivan (2004), Katrina (2005), Gustav (2008) and Ike (2008) from the Gulf of Mexico were used for skill assessment. The maximum wind radius was calculated using significant wind radii (R34, R50 and R64) reported by the National Hurricane Center. Different formulas for calculating the radius of maximum wind speed were evaluated. The asymmetric wind field for each hurricane was generated using analytic methods and compared with in situ data from buoys in the Gulf of Mexico and the H*Wind data. Analytical models were able to predict high wind speed under tropical cyclone conditions with relatively high precision. Among the analytical models evaluated in this research, the model proposed by Holland et al. (2010) showed excellent results. Dynamical wind models such as NCEP/NARR provide wind speed with the coarse spatial resolution which is acceptable for far-field locations away from the hurricane eye. In contrast, analytical models were able to produce sufficiently reliable wind speed within a particular radius from the center of the hurricane. Therefore blending of dynamical and analytical models can be used to provide accurate wind data during hurricane passage in the Gulf of Mexico.