This study aims to validate and improve the universal evaporation duct （UED） model through a further analysis of the stability function （ψ）. A large number of hydrometeorological observations obtained from a towe...This study aims to validate and improve the universal evaporation duct （UED） model through a further analysis of the stability function （ψ）. A large number of hydrometeorological observations obtained from a tower platform near Xisha Island of the South China Sea are employed, together with the latest variations inψ function. Applicability of different ψ functions for specific sea areas and stratification conditions is investigated based on three objective criteria. The results show that, under unstable conditions, ψfunction of Fairall et al. （1996） （i.e., Fairal196, similar for abbreviations of other function names） in general offers the best performance. However, strictly speaking, this holds true only for the stability （represented by bulk Richardson number RiB） range -2.6 ≤ RiB 〈 -0.1; when conditions become weakly unstable （-0.1 ≤ RiB 〈 --0.01）, Fairal196 offers the second best performance after Hu and Zhang （1992） （HYQ92）. Conversely, for near-neutral but slightly unstable conditions （-0.01≤ RiB 〈 0.0）, the effects of Edson04, Fairall03, Grachev00, and Fairal196 are similar, with Edson04 being the best function but offering only a weak advan- tage. Under stable conditions, HYQ92 is the optimal and offers a pronounced advantage, followed by the newly introduced SHEBA07 （by Grachev et al., 2007） function. Accordingly, the most favorable functions, i.e., Fairal196 and HYQ92, are incorporated into the UED model to obtain an improved version of the model. With the new functions, the mean root-mean-square （rms） errors of the modified refractivity （M）, 0-5-m M slope, 5-40-m M slope, and the rms errors of evaporation duct height （EDH） are reduced by 21.65%, 9.12%, 38.79%, and 59.06%, respectively, compared to the classical Naval Postgraduate School model.展开更多
对欧洲广泛使用的蒸发波导迭代(Musson-Genon Gauthier and Bruth,MGB)模型进行了研究,在介绍其基本原理的基础上,利用采集的实测数据得到了两种MGB迭代模式在中国海区的适用性结果.数据显示:以蒸发波导高度作为判别标准,MGB1迭代模式...对欧洲广泛使用的蒸发波导迭代(Musson-Genon Gauthier and Bruth,MGB)模型进行了研究,在介绍其基本原理的基础上,利用采集的实测数据得到了两种MGB迭代模式在中国海区的适用性结果.数据显示:以蒸发波导高度作为判别标准,MGB1迭代模式在试验海区预测的蒸发波导高度结果要好于MGB2迭代模式,同时也比解析MGB模式计算的波导高度结果更接近于实测值.展开更多
基金Supported by the National Natural Science Foundation of China(41205004,41230421,and 41105065)China Meteorological Administration Special Public Welfare Research Fund(GYHY201106004)
文摘This study aims to validate and improve the universal evaporation duct （UED） model through a further analysis of the stability function （ψ）. A large number of hydrometeorological observations obtained from a tower platform near Xisha Island of the South China Sea are employed, together with the latest variations inψ function. Applicability of different ψ functions for specific sea areas and stratification conditions is investigated based on three objective criteria. The results show that, under unstable conditions, ψfunction of Fairall et al. （1996） （i.e., Fairal196, similar for abbreviations of other function names） in general offers the best performance. However, strictly speaking, this holds true only for the stability （represented by bulk Richardson number RiB） range -2.6 ≤ RiB 〈 -0.1; when conditions become weakly unstable （-0.1 ≤ RiB 〈 --0.01）, Fairal196 offers the second best performance after Hu and Zhang （1992） （HYQ92）. Conversely, for near-neutral but slightly unstable conditions （-0.01≤ RiB 〈 0.0）, the effects of Edson04, Fairall03, Grachev00, and Fairal196 are similar, with Edson04 being the best function but offering only a weak advan- tage. Under stable conditions, HYQ92 is the optimal and offers a pronounced advantage, followed by the newly introduced SHEBA07 （by Grachev et al., 2007） function. Accordingly, the most favorable functions, i.e., Fairal196 and HYQ92, are incorporated into the UED model to obtain an improved version of the model. With the new functions, the mean root-mean-square （rms） errors of the modified refractivity （M）, 0-5-m M slope, 5-40-m M slope, and the rms errors of evaporation duct height （EDH） are reduced by 21.65%, 9.12%, 38.79%, and 59.06%, respectively, compared to the classical Naval Postgraduate School model.
文摘对欧洲广泛使用的蒸发波导迭代(Musson-Genon Gauthier and Bruth,MGB)模型进行了研究,在介绍其基本原理的基础上,利用采集的实测数据得到了两种MGB迭代模式在中国海区的适用性结果.数据显示:以蒸发波导高度作为判别标准,MGB1迭代模式在试验海区预测的蒸发波导高度结果要好于MGB2迭代模式,同时也比解析MGB模式计算的波导高度结果更接近于实测值.
