CAJ | 학술논문

利用NCEP 1°×1°分析资料、TMI海温资料、卫星云图资料对季风槽中南海台风榴莲(2001)生成机制进行了分析,揭示了大尺度环境流场、温暖洋面、中尺度对流活动对热带气旋(TC)生成的控制作用.结果表明,水平风速垂直切变的演变在一定程度上指示着TC在暖湿洋面上生成的时间,水平风速垂直切变由强向弱转变,在TC发生前18小时迅速减小到10 m/s,随后在10 m/s以下维持少变,垂直切变的变化主要反映了对流层高层环流形势的演变;在对流层中低层,季风槽的形成和加强对TC的生成有重要作用,由于热带温暖洋面作用,季风槽首先表现出有利于单体对流和带状对流发生发展的条件性对流不稳定特征,随着季风槽的加强,季风槽进一步表现出有利于中尺度扰动发生发展的正压不稳定特征;季风槽槽线南侧的低空急流的经向分布很宽广,由105°E越赤道气流和中南半岛偏西气流(其源头是索马里越赤道低空急流)汇合而成,急流的加强活动具有经向差异,由于边界层高θ_e空气辐合抬升产生两条经向距离约300 km的显著带状对流云系,槽线南侧风速分布的经向差异导致两条带状云系发生追赶,并逐步在季风槽底部槽线附近合并加强为MCC,进而导致中尺度涡旋(MCV)的产生并最终发展成为TC.分析结果还表明,为深对供应丰富对流有效位能的主要是来自台风发生区域本地南海暖洋面的地面热通量,南海暖洋面对TC生成有重要贡献.台风榴莲的生成是一个多尺度相互作用过程,主要包括涡旋对流热塔、与带状对流云系伴随的涡度带的升尺度,涡度带合并成长为MCV,以及大尺度条件对TC在季风槽中生成的时间及地点的控制作用等.
이용NCEP 1°×1°분석자료、TMI해온자료、위성운도자료대계풍조중남해태풍류련(2001)생성궤제진행료분석,게시료대척도배경류장、온난양면、중척도대류활동대열대기선(TC)생성적공제작용.결과표명,수평풍속수직절변적연변재일정정도상지시착TC재난습양면상생성적시간,수평풍속수직절변유강향약전변,재TC발생전18소시신속감소도10 m/s,수후재10 m/s이하유지소변,수직절변적변화주요반영료대류층고층배류형세적연변;재대류층중저층,계풍조적형성화가강대TC적생성유중요작용,유우열대온난양면작용,계풍조수선표현출유리우단체대류화대상대류발생발전적조건성대류불은정특정,수착계풍조적가강,계풍조진일보표현출유리우중척도우동발생발전적정압불은정특정;계풍조조선남측적저공급류적경향분포흔관엄,유105°E월적도기류화중남반도편서기류(기원두시색마리월적도저공급류)회합이성,급류적가강활동구유경향차이,유우변계층고θ_e공기복합태승산생량조경향거리약300 km적현저대상대류운계,조선남측풍속분포적경향차이도치량조대상운계발생추간,병축보재계풍조저부조선부근합병가강위MCC,진이도치중척도와선(MCV)적산생병최종발전성위TC.분석결과환표명,위심대공응봉부대류유효위능적주요시래자태풍발생구역본지남해난양면적지면열통량,남해난양면대TC생성유중요공헌.태풍류련적생성시일개다척도상호작용과정,주요포괄와선대류열탑、여대상대류운계반수적와도대적승척도,와도대합병성장위MCV,이급대척도조건대TC재계풍조중생성적시간급지점적공제작용등.
The genesis of Typhoon Durian (2001) from a monsoon trough over the South China Sea is investigated using the NCEP analysis, the TMI sea surface temperature (SST) data and satellite imageries. The results reveal the important roles of larger-scale flows, warm SSTs, and convectively generated vortices in determining the TC genesis. Of importance is the timing of the TC gene-sis. Durian appeared as the vertical wind shear decreased to a critical value of 10 m/s as a result of changing larger-scale flow pattern in the upper troposphere. It is shown that the monsoon trough was conditionally unstable to deep convection and barotropically unsta-ble to mesoscale disturbances. Low-level jets associated with a cross-equatorial flow and a westerly flow from Indo-China Peninsula provided favorable lifting of the high θ_e air in the boundary layer for the development of two major convective bands to the south of the trough axis. As the two convective bands, spaced meridionally about 300 km apart, moved toward the trough axis, the associated vortices were merged into the monsoon trough, leading to the generation of an MCV and its subsequent growth to typhoon intensity. It is also shown that surface heat fluxes from the underlying warm ocean played an important role in feeding convective available po-tential energy to deep convection during the TC genesis. We conclude that the genesis of Typhoon Durian involved multi-scale process-es, including vortical hot towers, upscale growth to vorticity bands, their merging to an MCV, and the large-scale control of the tim-ing and location within the monsoon trough.