研究了2005-2011年西北太平洋六对双台风个例,根据其路径特征将其分为三类:双台风同时转向;双台风一前一后移动;东台风转向、西台风原地打转或停滞不前等异常路径.利用WRF(Weather Research and Forecasting Model,V3.5.1)模式及其伴随...研究了2005-2011年西北太平洋六对双台风个例,根据其路径特征将其分为三类:双台风同时转向;双台风一前一后移动;东台风转向、西台风原地打转或停滞不前等异常路径.利用WRF(Weather Research and Forecasting Model,V3.5.1)模式及其伴随模式分别计算了各个台风的基于伴随模式的引导气流敏感性(Adjoint-Derived Sensitivity Steering Vector,ADSSV),在此基础上分析了不同移动类型的双台风之间的相互影响和环境场对其影响的差异,研究结果表明:ADSSV在垂直方向上主要分布在850 hPa和500 hPa之间,不同台风引导气流敏感性极值的高度具有较明显的差异;不同双台风ADSSV的水平分布特征也有显著不同,有的双台风之间的相互影响非常明显,有的双台风则属于单向影响型,还有的双台风虽然满足双台风的定义,但它们相互之间并没有明显的相互作用.展开更多
Based on best track data of tropical cyclones（TCs） from the Japan Meteorological Agency, the characteristics of suddenly reversed TCs（SRTCs）, which have turning angles usually approaching 180°, are statistica...Based on best track data of tropical cyclones（TCs） from the Japan Meteorological Agency, the characteristics of suddenly reversed TCs（SRTCs）, which have turning angles usually approaching 180°, are statistically analyzed from 1949 to 2011 over the western North Pacific Ocean. The typical large-scale circulation patterns of SRTCs are investigated using reanalysis data and dynamical composite analysis. Results show that turnings mainly occur in low latitudes between 10°N and 20°N,and mainly west of 135°E. The majority of SRTCs reach their peak intensity at, or slightly before, the turning time and subsequently decrease at some variable rate. Specifically, SRTCs are divided into four types, each containing two groups（i.e.eight groups in total） in terms of the moving-direction changes. The moving speed of all SRTC types except the south–north type decreases to its lowest during the 24 h, corresponding to a significant reduction in the primary steering components.According to the analysis of the 13 typical flow patterns found in this study, we suggest that sudden track changes are caused by the reversal steering flow. The original balance of the background flow patterns are broken up by new systems, e.g. binary TCs or dispersion-induced anticyclones. Additionally, sudden track changes are often due to double ridge variations of the subtropical high or weakened/strengthened high pressure in the east and west, respectively.展开更多
The characteristics of 200 hPa divergent wind and velocity potential have been analysed for four kinds of tropical cyclone tracks having impact on the SOuth China Sea. It is found that the difference of monsoon circul...The characteristics of 200 hPa divergent wind and velocity potential have been analysed for four kinds of tropical cyclone tracks having impact on the SOuth China Sea. It is found that the difference of monsoon circulation in 200 hPa divergence wind field may affect the medium-range movement characteristics of tropical cyclone tracks. Corresponding to the west Pacific subtropical high,the orientation of 200 hPa secondary convergence line and its extension to the west may indicate the variability of track types.The direction of tropical cyclone movement is 2 longitudes west of and parallel to the 200 hPa secondary divergence line.展开更多
文摘研究了2005-2011年西北太平洋六对双台风个例,根据其路径特征将其分为三类:双台风同时转向;双台风一前一后移动;东台风转向、西台风原地打转或停滞不前等异常路径.利用WRF(Weather Research and Forecasting Model,V3.5.1)模式及其伴随模式分别计算了各个台风的基于伴随模式的引导气流敏感性(Adjoint-Derived Sensitivity Steering Vector,ADSSV),在此基础上分析了不同移动类型的双台风之间的相互影响和环境场对其影响的差异,研究结果表明:ADSSV在垂直方向上主要分布在850 hPa和500 hPa之间,不同台风引导气流敏感性极值的高度具有较明显的差异;不同双台风ADSSV的水平分布特征也有显著不同,有的双台风之间的相互影响非常明显,有的双台风则属于单向影响型,还有的双台风虽然满足双台风的定义,但它们相互之间并没有明显的相互作用.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41230421, 41005029 and 41105065)the National Public Benefit (Meteorology) Research Foundation of China (Grant No. GYHY201106004)
文摘Based on best track data of tropical cyclones（TCs） from the Japan Meteorological Agency, the characteristics of suddenly reversed TCs（SRTCs）, which have turning angles usually approaching 180°, are statistically analyzed from 1949 to 2011 over the western North Pacific Ocean. The typical large-scale circulation patterns of SRTCs are investigated using reanalysis data and dynamical composite analysis. Results show that turnings mainly occur in low latitudes between 10°N and 20°N,and mainly west of 135°E. The majority of SRTCs reach their peak intensity at, or slightly before, the turning time and subsequently decrease at some variable rate. Specifically, SRTCs are divided into four types, each containing two groups（i.e.eight groups in total） in terms of the moving-direction changes. The moving speed of all SRTC types except the south–north type decreases to its lowest during the 24 h, corresponding to a significant reduction in the primary steering components.According to the analysis of the 13 typical flow patterns found in this study, we suggest that sudden track changes are caused by the reversal steering flow. The original balance of the background flow patterns are broken up by new systems, e.g. binary TCs or dispersion-induced anticyclones. Additionally, sudden track changes are often due to double ridge variations of the subtropical high or weakened/strengthened high pressure in the east and west, respectively.
文摘The characteristics of 200 hPa divergent wind and velocity potential have been analysed for four kinds of tropical cyclone tracks having impact on the SOuth China Sea. It is found that the difference of monsoon circulation in 200 hPa divergence wind field may affect the medium-range movement characteristics of tropical cyclone tracks. Corresponding to the west Pacific subtropical high,the orientation of 200 hPa secondary convergence line and its extension to the west may indicate the variability of track types.The direction of tropical cyclone movement is 2 longitudes west of and parallel to the 200 hPa secondary divergence line.
