Comparison and further development of parametric tropical cyclone models for storm surge modelling

Cyclone forced storm surges cause severe damage to coastal structures and loss of human lives and properties. In cyclone protection and warning it is important to be able to calculate the cyclone air pressure and wind field on the basis of rather limited information, such as cyclone position, pressure drop, maximum wind speed and radius to maximum wind speed. In the present work, parametric cyclone models based on such limited information are investigated and compared. Analytical expressions of the tangential and radial velocity distributions are derived from the governing momentum equations. It is found that the analytical models provide very similar air pressure and tangential wind speed distributions. Instead of using a simple formulation of the deflection angle, the derived analytical expression of the radial velocity distribution is used and compared to earlier numerical solutions. A procedure is formulated for estimation of the shape of the cyclone on the basis of maximum wind speed versus pressure drop relations. Finally, examples of comparisons of measured and calculated air pressures and wind speeds and directions are presented.