南海-西北太平洋季风槽中热带气旋群发的研究Ⅱ.影响机制研究
Research on the cluster of tropical cyclogenesis in the South China Sea-western north Pacific monsoon trough Ⅱ. Mechanism of the influence
-
摘要: 应用1979-2005年西北太平洋热带气旋(TC)资料和OLR,NCEP/DOE AMIP-Ⅱ再分析逐日资料,探讨南海-西北太平洋季风槽中TC(简称MTTC)群发的可能机理,得到以下几点结论:(1)5~10月季风槽强度及形态与索马里越赤道气流的强弱、副高的位置以及南半球澳洲冬季风的强弱密切相关,不同区域季风槽强度增强都可能导致MTTC群发。(2)MTTC群发与季风槽强度的低频振荡密切相关,当季风槽强度30~60 d振荡处于活跃期,准双周10~20 d的振荡也处于活跃期时,有利于MTTC的群发。(3)副高的位置、索马里越赤道气流以及西太平洋越赤道气流的低频振荡的位相配置将影响季风槽强度和形态,进而影响MTTC群发。副高东退或位置偏北,索马里越赤道气流或西太平洋越赤道气流增强或同时增强,季风槽偏北或东伸,皆有利于MTTC群发;副高偏西偏南,索马里越赤道气流增强或西太平洋越赤道气流增强,季风槽偏南,该类型MTTC群发比例较低,群发次数偏少。(4)典型个例分析表明,由于季风槽强度和形态的差异造成MTTC主要生成区对流条件以及水汽条件的差异,致使MTTC群发的年际差异。
-
关键词:
- 南海-西北太平洋季风槽 /
- 热带气旋 /
- 群发 /
- 影响机制
Abstract: By using the western north Pacific tropical cyclone(TC)data, OLR data and the NCEP/DOE AMIP-Ⅱ reanalysis daily data during 1979-2005, the possible mechanism of the cluster of TCs in the South China Sea (SCS)-western north Pacific monsoon trough (CTC) are discussed, the main results are as follows: (1)During May-October, the intensity and pattern of monsoon trough are closely related to the strength of Somalia’s cross-equatorial flow, the location of western north Pacific subtropical high (WNPSH) and the intensity of the Southern Hemisphere Australian winter monsoon. Enhanced intensity of monsoon trough in different regions may lead to CTC. (2) CTC and the low-frequency oscillations of monsoon trough are closely connected.. the CTC often occurs when the monsoon trough is in the active phase both of 10~20 and 30~60 d oscillations . (3) CTC is affected by intensity and pattern of monsoon trough which are related to the location of WNPSH, the intra-seasonal oscillation phases of cross-equatorial flows over the Somalia and western Pacific. It supplies favorable conditions to CTC when WNPSH retreats to eastward or is in the north of mean and the cross-equatorial flows enhance either over Somalia or the western Pacific, as well as enhance in both of them. When WNPSH is west and south to the normal, the cross-equatorial flows enhance over Somalia area or the western Pacific, the monsoon trough is located southward leading to less CTC. (4) Typical cases analysis shows that CTC exhibits inter-annual variation due to the different convection and moisture conditions in the main TC generating areas which are caused by the different intensity and pattern of monsoon trough. -
GRA W M. Global view of the origin of tropical disturbances and storms[J]. Mon Wea Rev,1968,96(10):669-700. DING Y H. Monsoon over China[M]. Dordrecht/Boston/London:Kluwer Academic Publisher, 1994:419. HARR P A,ELSBERRY R L. Tropical cyclone track characteristics as a function of large-scale circulation anomalies[J]. Mon Wea Rev, 1991,119(6):1448-1468. HARR P A, ELSBERRY R L.large-scale circulation variability over the tropical western north Pacific:Part Ⅰ.Spatial patterns and tropical cyclone characteristics[J]. Mon Wea Rev, 1995,123(5): 1225-1246. 王慧,丁一汇,何金海.西北太平洋夏季风的变化对台风生成的影响[J].气象学报,2006,64(3):345-356. 黄荣辉,陈光华.西北太平洋热带气旋移动路径的年际变化及其机理研究[J].气象学报,2007,65(5):683-694. 孙淑清, 刘舸, 张庆云.南半球环流异常对夏季西太平洋热带气旋生成的影响及其机理[J].大气科学,2007,31(6):1189-1200. 高建芸,张秀芝,江志红,等.西北太平洋季风槽异常与热带气旋活动[J].海洋学报,2008,30(3):35-47. 陈联寿,丁一汇.西太平洋台风概论[M].北京:科学出版社,1979:109. LI T,FU B.Tropical cyclogenesis associated with Rossby wave energy dispersion of a preexisting typhoon:Part Ⅰ.Satellite data analyses[J].J Atmos Sci ,2006,63:1377-1389. KROUSE K,SOBEL A.An observational study of multiple tropical cyclone events in the western north Pacific[J]. Tellus, 2010,62(3):256-265. KUO H-C, CHEN J-H, WILLIAMS R T,et al . Rossby waves in zonally opposing mean flow: behavior in the northwest Pacific summer monsoon[J]. J Atmos Sci, 2001,58:1035-1050. 高建芸,吕心艳,鲍瑞娟,等.南海-西北南太平洋季风槽中热带气旋群发的研究:Ⅰ.热带气旋群发基本特征[J].海洋学报,2010,32(6):64-71. 罗树森. 南半球气流对低纬度环流和台风发生的影响 //一九八零年热带天气会议文集.北京:科学出版社,1981:172,969-973. 张元箴,王淑静.南半球与西太平洋副热带高压和台风群中期活动的关系[J].应用气象学报,1999,10(1):80-87. -
计量
- 文章访问数: 1516
- HTML全文浏览量: 19
- PDF下载量: 1288
- 被引次数: 0
下载:
