Characteristics and Causes Analysis of Storm Surges under the Effect of Cold Air Outbreaks in the Bohai Sea

Abstract

Based on the synchronous tidal data observed from 12 tide stations of the Bohai Sea in a year, the characteristics and causes of storm surges under the effect of cold air outbreaks have been analyzed using the method of harmonic analysis. The results show that the phenomena of abnormal sea-level events are affected remarkably by strong winds due to landform of the Bohai Sea. Under the effect of north and northwest winds, negative storm surges appear successively in the northern part of the Bohai Sea, and in the southern part of the Bohai Sea, first positive storm surges appear and then negative storm surges appear successively. After the wind direction has changed into southerly, the values of negative storm surges decrease gradually, until positive storm surges appear at the tide stations of the Bohai Sea. In the final analysis, maximum negative storm surges or maximum positive storm surges appeared at the tide stations in the southern part of the Bohai Sea lag than that in the northern part. Therefore, in order to provide beneficial service for marine activities, the mariners should pay attention to the positive storm surge on the high water and to the negative storm surge on the low water.