摘要:
利用《西北太平洋热带气旋年鉴》资料,简要分析了影响上海地区可能最高潮位的台风路径、强度变化特征.分析表明,造成上海地区严重风暴潮的台风路径有3种类型,它们分别是登陆浙江沿海西行类、近海北上类和正面袭击上海类.上海及其近海区域台风强度随纬度增加而减弱的变化特征明显,在东海北部,近50a内尚未出现过中心气压低于920hPa的台风.利用特定的统计模式,根据假想台风路径、强度变化给出的可能最大增水只有210cm,其值明显偏小,认为用统计方法进行上海地区最大可能增水的估算似乎不合适.在考虑可能变化的台风路径、强度、移动速度以及天文大潮汛等综合因素后,利用高分辨率ECOM-Si的数值模式计算出的上海地区(吴淞)可能最大增水是由5612台风以10km/h速度北抬纬度2°并取所在位置的历史最低气压值造成的,其可能最大增水为367cm,如以长江口区天文可能高潮值420cm计算,则获得长江口的最大可能水位为787cm.
Abstract:
The characterization of track and intensity change of tropical cyclone is analyzed that induces remarkable storm surge.It is shown that there are three kinds of track that affect Shanghai,they are westward moving of landfalling at the east coast of Zhejiang Province,northward moving inshore and positively hit Shanghai on the sea.The change in the tropical cyclone intensity as it passes the area near to Shanghai is remarkable.In general,the minimum surface level pressure of tropical cyclene center near to Shanghai is greater than 920 hPa.The probable maximum water level in Shanghai area estimated using the statistical method is about 210 cm.This is not suitable for the estimation of water level in Shanghai due to the lack of statistical method for the description of small probability.The results of numerical simulation indicate that considering the combination of probable tracks,estimated intensities and various velocities of tropical cyclone movement,the probable maximum water levels are calculated using a three-dimensional numerical model.The result indicates that the probable maximum water level appears when the track of TC 5612 is set to move 2°in latitude and the minimum sea surface pressure takes the lowest value in Shanghai.The estimated probable water level is 787cm.
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