Comparative analyses of the heavy rainfall associated with landfalling tropical cyclones SOULIK (1307) and MARIA (1808) with similar routes
Comparative analyses of the heavy rainfall associated with landfalling tropical cyclones SOULIK (1307) and MARIA (1808) with similar routes
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DOI：
10.1016/j.atmosres.2022.106124
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发表时间：
2022-03
影响因子：
5.5
通讯作者：
Ling Yan;Yushu Zhou;Xuanfei Liu;Yanbin Huang;Yongqing Wang
中科院分区：
文献类型：
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作者：
Ling Yan;Yushu Zhou;Xuanfei Liu;Yanbin Huang;Yongqing Wang
利用ERA5和CMORPH再分析资料，分析了SOULIK（1307）和MARIA（1808）热带气旋登陆福建省前后的不同降水演变过程。这两个台风的路径、移动速度和着陆点相似，但在降雨强度和相对于路线的位置上表现出不同的不对称特征。研究结果主要体现了两个地区内陆降水分布及其影响因素的差异。与“SOULIK”有关的暴雨路径左侧的陆地持续暴雨是有利的动力条件所致。SOULIK的东北向外流受到上层偏东风波的加强，在吸力作用下产生了强烈的辐散和明显的上升运动。强环境VWS破坏了SOULIK暖核结构，该暖核结构指向西南偏南方向，与200 hPa强东北风相关，进一步导致TC路径左侧降水格局更加不对称。此外，在SOULIK以南的中层观测到一次冷侵入，增强了对流不稳定，与SOULIK以南冷暖平流由低层向高层交替的情况相吻合，进一步加剧了TC路径左侧的降水。同时，低层偏南风增强引起的经向水汽辐合对苏力克以南强降水的维持起了关键作用。与MARIA相关的陆地48h累积雨量明显弱于与SOULIK相关的陆地48h累积雨量，且最大值在其北侧。由占优势的东风与沿海地形相互作用引起的低层强辐合，以及南亚高压南部与高空急流相吻合的明显辐散，为MARIA以北的最大降水提供了有利的动力条件。同时，南海上空的强西风带与西北太平洋上空的东部气旋系统一起，为MARIA北侧的降雨创造了有利的水汽条件。本研究的结果提高了对由登陆的tc，特别是具有相似路径的tc决定暴雨降水演变的物理机制的预测理解
Different rainfall evolutions associated with landfalling tropical cyclones (TCs) SOULIK (1307) and MARIA (1808) are analyzed before and after they made landfalls in Fujian province based on reanalysis data of the ERA5 and CMORPH data. The two TCs shared similar tracks, motion speed as well as landing points, but showed different asymmetric features of rainfall intensities and locations relative to routes. The results primarily exhibited the discrepancy of the inland rainfall distributions between the two TCs and the related influence factors. The constant torrential rain over land with the maximum on the left of the storm track associated with SOULIK was attributed to favorable dynamical conditions. The northeasterly outflow of SOULIK was reinforced by the easterly wave in upper-level, which induced strong divergence along with the distinct ascending motions by suction effect. The strong ambient VWS broke the warm core structure of SOULIK, which pointed to south-southwest direction relevant to the strong northeasterly wind at 200 hPa, and further caused a more asymmetric rainfall pattern on the left of TC track. Besides, a cold intrusion was observed south of SOULIK in mid-levels, enhancing convective instability coincident with the alternating circumstance of cold and warm advections from the lower layer to the upper layer over south of SOULIK, which further intensify the precipitation on the left of TC track. Simultaneously, the meridional moisture convergence owing to the enhanced southerly wind at lower level played a key role in the maintenance of severe rainfall south of SOULIK. Comparatively, the 48-h accumulated rainfall over land associated with MARIA was much weaker than that associated with SOULIK, and the maximum is on the northern side. The strong convergence in the lower level induced by the predominant easterly winds interacting with coastal terrains, as well as the distinct divergence coincident with the upper level jet in the southern part of the South Asia High (SAH), provide favorable dynamical conditions for the maximum rainfall north of MARIA. Simultaneously, the strong westerlies over the South China Sea, together with the eastern cyclonic system over the Northwest Pacific, create favorable moisture conditions for the rainfall on the northern side of MARIA. Results presented in this study provides an improved predictive understanding of physical mechanism dictating storm rainfall evolution from landfalling TCs, especially those with similar tracks