【作者】 郝民； 徐枝芳；

【Author】 Min Hao and Zhifang Xu National Meteorological Center, Beijing 100081, China

【机构】 国家气象中心；

【摘要】 由于初始质量场和风场之间的不协调,从而激发出虚假的高频振荡,产生Spin-up现象.当模式分辨率提高,同化周期加快,这个问题变的更加突出.如何在尽可能短的时间内克服Spin-up现象,有效地滤去初始场中的不合理的高频重力波,是资料同化发展必须解决的问题.近年的研究表明:数字滤波技术应用于业务和科研预报中,能较好的消除模式虚假的高频振荡.本工作将数字滤波初始化方法应用于WRF精细尺度模式的研究中,并将不同的数字滤波应用形式引入到WRF模式中,通过试验比较,达到较好地保留初始场信息,有效的滤掉虚假的高频振荡的目的.更多还原

【Abstract】 Spurious high-frequency oscillations would be caused by the inconsistency between initial mass fields and wind fields, which lead to spin-up phenomena in the modeling. Such a problem could be serious when the model-grid resolution is raised and the assimilation period is reduced. Thus, how to effectively remove the spurious gravity waves in the initial fields and restrain spin-up occurrence in a assimilation period as short as possible, become one of the most important tasks in the improvements of assimilation capability. The studies in the recent years indicated that the application of digital filtering technique could effectively remove the spurious high-frequency oscillations in the operational/research modeling. In this study, the different methods of digital filtering initialization were applied for the WRF model, and their performances were compared. The results showed that this technique could remain the essential contents in the initial fields while filtering the spurious high-frequency oscillation effectively.更多还原