四维变分同化方法在台风初始化及其数值模拟中的应用--对9608号(Herb)台风的研究结果   总被引：4，自引：2，他引：2  

ZHANG Xiaoyan  WANG Bin  JI Zhongzhen  Qingnong XIAO  ZHANG Xin 《大气科学进展》2003,20(4):612-622

The MM5 and its four dimensional variational data assimilation (4D-Var) system are used in this paper. Based on the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data, the authors generate an optimal initial condition for a typhoon by using the bogus data assimilation (BDA) scheme. BDA is able to recover many of the structural features of typhoons including a warm-core vertex, the correct center position, and the strong circulation.As a result of BDA using a bogus surface low, dramatic improvement is achieved in the 72 h prediction of typhoon Herb. Through several cases, the initialization by BDA effectively generates the harmonious inner structure of the typhoon, but which is lacking in the original analysis field. Therefore the intensity forecast is improved greatly. Some improvements are made in the track forecast, but more work still needs to be done.  相似文献   

杨树抑螺防病林林下草本植物的物种多样性   总被引：2，自引：0，他引：2  

吴敏  吴立勋  汤玉喜  徐世凤 《湿地科学与管理》2006,2(4):20-23

对滩地杨树抑螺防病林草本植物层的物种组成和多样性进行了8年动态监测。随林龄增加,草本层的物种丰富度降低、个体总数增加;部分喜光性物种被更加耐荫的植物种类所更替,其β多样性增加;原有物种和优势种的保持率分别为56.3%和66.7%,草本层组成保持相对稳定。与造林前期比较,主伐阶段林下草本层α多样性变化不大。  相似文献   

四维变分同化方法在台风初始化及其数值模拟中的应用——对9608号(Herb)台风的研究结果(英)     

张晓艳  王斌  季仲贞  肖庆农  张昕 《大气科学进展》2003,(4)

采用MM5数值预报模式,以及以MM5和它的伴随模式为基础的四维变分同化系统,以NCEP/NCAR再分析资料为背景场,运用BDA(bogus data assimilation)方案优化热带气旋的初始结构,从而一定程度上弥补了海洋上资料缺乏所造成的台风中心位置不准确,台风环流偏弱,台风内部结构不完整等问题,在此基础上对台风进行了72小时数值预报。通过对多个台风个例的研究表明,BDA方案对台风的初始化处理,有效性地构造出了原来分析场所缺乏的台风内部结构,并且与模式初始场协调,因而大大改进了台风中心强度的预报,对于台风路径的预报也有改进,但不是十分理想,还有待提高。  相似文献