崔晓鹏,吴国雄,高守亭. 2002. 西大西洋锋面气旋过程的数值模拟和等熵分析[J]. 气象学报, 60(4):385-399, doi:10.11676/qxxb2002.046
西大西洋锋面气旋过程的数值模拟和等熵分析
NUMERICAL SIMULATION AND ISENTROPIC ANALYSIS OF FRONTAL CYCLONES OVER THE WESTERN ATLANTIC OCEAN
投稿时间:2001-04-28  修订日期:2001-12-06
DOI:10.11676/qxxb2002.046
中文关键词:  上滑倾斜涡度发展  MM5  海洋气旋
英文关键词:Up-sliding slant ise vorticity development  MM5  Oceanic cyclogenesis
基金项目:海外青年学者合作研究基金(49825504,49928504)和我国重大天气灾害的形成机理和预测理论研究(G1998040907).
作者单位
崔晓鹏 中国科学院大气物理研究所LASG, 北京, 100029 
吴国雄 中国科学院大气物理研究所LASG, 北京, 100029 
高守亭 中国科学院大气物理研究所LASG, 北京, 100029 
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中文摘要:
      文中使用PSU/NCARMM5非静力数值模式对1992年3月13~15日发生在西大西洋上的一次海洋气旋爆发过程进行了60h的模拟;基于倾斜涡度发展理论,从等熵面倾斜的角度研究了气旋的发生、发展、运动和变化,利用高分辨率模拟结果对这次过程进行了分析.模拟结果很好地再现了气旋的发生、移动、加深、气旋的热力结构以及地面环流等特征.其中主要气旋M在60h的模拟中共降压45hPa;第36~42时(模式时间)6h内降压达12hPa.剖面图及等熵面图分析指出,气旋的发生、发展、运动和变化与等熵面或等相当位温面的倾斜密切相关,气旋中心总是位于等熵面或等相当位温面近于垂直的对流中性地区,这与倾斜涡度发展理论的阐述是一致的.气旋在弱静力稳定度的海洋表面启动发展之后,气旋与大尺度环境场相互作用,气旋得到迅速发展.“倾斜涡度发展理论”(以下简称SVD理论)可以很好地解释此次海洋锋面气旋的发展与移动.气旋的发展和移动与等熵面的倾斜密切相关,发展期气旋前部及其移动路径前方自组织的斜升气流与倾斜的等熵面相配合,共同构成上滑“倾斜涡度发展”(SVD理论的推广,以下简称USVD理论)的必要因子,在一定的条件下(ĊD<0,CD为SVD指数),使得气旋及其前方,尤其是移动路径前方出现USVD发展,造成气旋发展和移动.
英文摘要:
      Frontal cyclogenesis is a widespread weather phenomenon.In spite of the marked improvements in the study of this kind of phenomenon,many problems ramain.Our understanding and prediction of this type of mesoscale vortex is still hampered by(1)the lack of high-resolution data and(2)the absence of theoretical models.This kind of understanding and forecast is still among the most serious challenges to at mospheric scientists.Here by using PSU/N CAR MM5 mesoscale model,a 60-h simulation is performed to reproduce a frontal cyclogenesis over the Western At lantic Ocean during March 13-15,1992.Beginning with Slantwise Vorticity Development(SVD),the genesis,development and propagation are studied by using high-resolution model output in the context of slantwise isentropic surface.And inspiring results are received.The model reproduces well the genesis,track and intensity of the cyclones,their associated thermal structure as well as their surface circulation.The major cyclone(M)deepens 45hPa in the all 60h and 12hPa in 6h from 36 to 42(model time)and 27hPa in 24h from 36 to 60(model time).Profile and isentropic analysis tell us that the cyclogenesis is in very close relation with slantwise isentropic surface;The cyclones always superpose with the core of neutral convection stability with nearly vertical isentropic surface,which coincides with what SVD says.Beginning with Slantwise Vorticity Development(SVD),the development and propagation of the oceanic frontal cyclone are studied by using high-resolution model output in the context of slantwise isentropic surface.The results show that the frontal cyclone deepens rapidly by interaction with large-scale environment after occurring over ocean with weak hydrostatic stability;SVD theory can well translate the development and propagation,which is closely related with slant wise isentropic surface.The downstream slantwise upsliding movement and declination of isentropic surface make vorticity develop(USVD)under favorable conditions(CD<0,here CD is SVD index),and result in the moving and development of cyclone.
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