Simulation of Extreme Surges in the Taganrog Bay with Atmosphere and Ocean Circulation Models

Abstract

The simulation the most extreme surges over the period of instrumental observations in the Taganrog Bay since 1881, the surges occurred on March 24, 2013 and September 24, 2014. The objective of the simulation is to study surge formation features and to reveal requirements for the accuracy of simulating atmospheric and oceanic circulation in the Sea of Azov. For this purpose, the Institute of Numerical Mathematics Ocean Model (INMOM) with the spatial resolution of ~4 km and ~250 m was used. The atmospheric forcing over the Black Sea region was specified using ERA-Interim reanalysis data and WRF model data with the spatial resolution of 80 and 10 km, respectively. It is shown that the quality of simulation of extreme surges in the Sea of Azov is more dependent on the quality of the input atmospheric forcing than on the spatial resolution of the ocean circulation model. The usage of WRF data as atmospheric forcing allows the more accurate simulation of extreme surges. However, the simulation of the extreme surge of 2014 overestimates, and simulations for the 2013 surge underestimate the surge level. Evidently, as the used version of INMOM does not take into account the coastal zone flooding, the maximum surge value is overestimated.