登陆台风Matsa(麦莎)中尺度扰动特征分析  

Analysis of the Characteristics of Mesoscale Disturbance for Landfalling Typhoon Matsa

作　　者：冀春晓 赵放 高守亭[3] 刘黎平[4] 

机构地区：[1]浙江省气象科学研究所,杭州310017 [2]浙江省气象台,杭州310017 [3]中国科学院大气物理研究所,北京100029 [4]中国气象科学研究院,北京100081

出　　处：《大气科学》2012年第3期551-563,共13页Chinese Journal of Atmospheric Sciences

基　　金：国家自然科学基金资助项目90815028;国家公益性行业(气象)科研专项GYHY201106035

摘　　要：地面中尺度自动站和多普勒雷达资料的分析都表明,台风Matsa登陆后的低层螺旋云带中活跃着中尺度气旋性涡旋系统。本文使用新一代中尺度WRF模式对台风Matsa登陆后的变化特征进行了数值模拟,使用四维变分多普勒雷达分析系统(4D-VDRAS)对台风Matsa多普勒雷达径向风进行了风场反演。在此基础上对台风Matsa登陆后中尺度扰动特性进行了初步探讨;对台风Matsa与其螺旋云带的中尺度系统之间动能和涡度的相互转换进行了诊断分析。分析表明:(1)数值模拟和雷达风场反演结果表明,登陆台风Matsa的低层螺旋云带中活跃着中尺度气旋式涡旋系统,与之相伴随的为较强的中尺度上升区,而且,中尺度垂直上升运动的强弱与雷达对流回波强度成正相关,中尺度垂直上升运动越强,雷达对流回波发展越旺盛。(2)台风Matsa与其中尺度系统动能转换的诊断分析说明,低层中尺度系统从台风Matsa环流中获得动能而发展;Matsa在陆地上长久维持主要是从高层获得动能。(3)台风Matsa与其中尺度系统涡度转换的诊断分析说明,低层中尺度系统向Matsa输送正涡度主要依靠中尺度垂直运动来完成;高层正涡度的转换通过水平输送和垂直输送共同来完成。所以,中尺度系统所产生的正涡度源源不断地向Matsa输送,使Matsa的气旋性环流可以在陆地上长久维持。Doppler radar reflectivity and the surface automatic weather stations （AWS） wind observations demon- strate that the mesoscale cyclonic eddies at the low level are active in the spiral-cloud bands of landfalling typhoon Matsa. Numerical simulation has been carried out to investigate the evolution characteristics of typhoon Matsa in 2005 after its landfalling by using the new-generation mesoscale weather research and forecasting （WRF） model, and the four-dimensional variational Dopple radar analysis system （4D-VDRAS） is used to retrieve single-Doppler velocity. Then a preliminary study has been made on the mesoseale features of typhoon Matsa after landfalling in parallel with diagnostic analyses of the conversion of kinetic energy and vorticity between typhoon Matsa and me- soscale systems on the area mean basis. Results show that： （1） The results of numerical simulation and Doppler ra- dial velocity retrieval indicate that the mesoseale cyclonic eddies at the low level are active in the spiral-cloud bands of landfalling typhoon Matsa, and there is severe mesoscale upward movement accompanying the mesoscale cyclonic ed- dies. The stronger the mesoscale upward movement is, the larger Doppler radar reflectivity is. （2） The diagnostic results of the kinetic energy conversion between Matsa and mesoscale systems demonstrate that the mesoscale cyclonic eddies at the low level obtain kinetic energy from landfalling typhoon Matsa to develop, whilst Matsa obtains kinetic energy from the mesoscale disturbances in the upper layers to be sustained after landfalling. （3） The diagnostic results of the vorticity conversion between Matsa and mesoscale systems show that Matsa obtains positive vorticity from the mesoscale cyclonic eddies at the low levels by means of the mesoscale upward movement, but in the upper layers, both the mesoscale horizontal and vertical movements play important roles. Therefore, the positive cyclonic vorticity is transported continuously to Matsa, and Matsa could be sustained fo

关 键 词：登陆台风 中尺度扰动 维持 动能和涡度转换 

分 类 号：P444[天文地球—大气科学及气象学]