An Application of the Adjoint Method to a Statistical-Dynamical Tropical-Cyclone Prediction Model （SD-90） Ⅱ： Real Tropical Cyclone Cases

In the first paper in this series, a variational data assimilation of ideal tropical cyclone （TC） tracks was performed for the statistical-dynamical prediction model SD-90 by the adjoint method, and a prediction of TC tracks was made with good accuracy for tracks containing no sharp turns. In the present paper, the cases of real TC tracks are studied. Due to the complexity of TC motion, attention is paid to the diagnostic research of TC motion. First, five TC tracks are studied. Using the data of each entire TC track, by the adjoint method, five TC tracks are fitted well, and the forces acting on the TCs are retrieved. For a given TC, the distribution of the resultant of the retrieved force and Coriolis force well matches the corresponding TC track, i.e., when a TC turns, the resultant of the retrieved force and Coriolis force acts as a centripetal force, which means that the TC indeed moves like a particle; in particular, for TC 9911, the clockwise looping motion is also fitted well. And the distribution of the resultant appears to be periodic in some cases. Then, the present method is carried out for a portion of the track data for TC 9804, which indicates that when the amount of data for a TC track is sufficient, the algorithm is stable. And finally, the same algorithm is implemented for TCs with a double-eyewall structure, namely Bilis （2000） and Winnie （1997）, and the results prove the applicability of the algorithm to TCs with complicated mesoscale structures if the TC track data are obtained every three hours.     

影响浙江中南部台风的统计分析和预报思路

本文首先用 20 a 的资料对影响我国浙江中南部沿海地区的台风作了统计分析.结果表明,影响该地区的台风的活动存在着明显的时间和地域特征;然后从动力学热力学角度探讨了此类台风生成、发展、移动的机制,给出了其预报的思路和今后须进一步重视和研究的问题.     

γ值的变化在超低空飞行中的重要性研究

近年来在通用航空超低空飞行中不乏因为各种气象原因而造成各类事故和事故征候的情况发生.对小型航空器而言,冬季的飞行事故频率往往大于其他季节.究其原因,其中一个重要问题是由于小型航空器一般都无除冰装置,而对于其飞行中可能遭遇到的低温、高湿天气来讲,尾翼和旋翼结冰是极易产生的现象.本文试图解释近地面层和低层大气的气温垂直分布特点.探索低层和近地面层大气中气温垂直变化规律,对相关人员尤其是与小型航空器飞行有关的飞行、航空气象预报、管制人员有所帮助.一般而言,悛凳侵该堪倜卓掌奈露却怪递减率?糎T〗