The Relationship between Convective Bursts and Warm-Core Intensification in a Nonhydrostatic Simulation of Typhoon Lionrock (2016)
The Relationship between Convective Bursts and Warm-Core Intensification in a Nonhydrostatic Simulation of Typhoon Lionrock (2016)
复制标题
DOI：
10.1175/mwr-d-18-0457.1
复制
发表时间：
2019-04
影响因子：
3.2
通讯作者：
R. Oyama;A. Wada
中科院分区：
文献类型：
--
作者：
R. Oyama;A. Wada
2016年的台风狮岩在热带气旋中较为罕见，因为它在西北太平洋的季风环流以东形成，并以逆时针方向移动。系统在对流层上层风和垂直风切变较弱的季风环流中迅速增强。本研究使用一个3公里网格非静力模式来研究台风Lionrock的暖心增强，这与气旋尺度的强对流有关[即，对流爆发（CB）]。模拟再现了多个CB的时间间隔为1天或更短，这与日周期和其他短时间尺度的变化在TC对流。每个CB往往在0-12 h之前在TC中心附近的峰值温度异常，表明暖心加强发生由于强烈的眼壁对流释放的非绝热加热。值得注意的是，上升气流由于对流在增强阶段比那些发生在成熟和衰减阶段，和对流层上层暖核的最高温度异常迅速增加眼壁形成期间。此外，研究还表明，与CBs相关的大部分不对称的内核强对流，是由垂直风切变引起的，有助于暖芯加强。此外，TC内核内的位温收支分析表明，由于眼内对流层顶附近的沉降（通常在CB之后）而产生的绝热加热对眼的发展至关重要。滞后相关性表明，CBs与眼内沉降之间的滞后时间为3-9 h。
Typhoon Lionrock (2016) was unusual among tropical cyclones (TCs) in that it formed east of the monsoon gyre in the western North Pacific, and moved counterclockwise. It rapidly intensified in the monsoon gyre in an environment of weak upper-tropospheric winds and vertical wind shear. This study used a 3-km mesh nonhydrostatic model to examine the warm-core intensification of Typhoon Lionrock, which was associated with cyclone-scale vigorous convection [i.e., convective bursts (CBs)]. The simulation reproduced the multiple CBs at intervals of 1 day or shorter, which were related to the diurnal cycles and other short time-scale variations in the TC convection. Each CB tended to precede peak temperature anomalies near the TC center by 0–12 h, indicating that the warm-core intensification occurred due to diabatic heating released by the vigorous eyewall convection. Notably, updrafts due to convection during the intensification phase were stronger than those occurring during the mature and decay phases, and the maximum temperature anomaly of the upper-tropospheric warm core rapidly increased during eyewall formation. In addition, this study indicated that most of the asymmetric inner-core vigorous convection associated with CBs, which was induced by the vertical wind shear, contributed to the warm-core intensification. Furthermore, the budget analysis of potential temperature within the TC inner core showed that adiabatic heating due to subsidence from near the tropopause within the eye, often following CBs, was essential in developing the eye. The lag correlation suggested the lag time between the CBs and the subsidence within the eye was 3–9 h.