How the Speed and Latitude of the Jet Stream Affect the Downstream Response to Recurving Tropical Cyclones
How the Speed and Latitude of the Jet Stream Affect the Downstream Response to Recurving Tropical Cyclones
复制标题
急流的速度和纬度如何影响下游对回归热带气旋的响应
DOI：
10.1175/mwr-d-19-0049.1
复制
发表时间：
2019
影响因子：
3.2
通讯作者：
J. Doyle
中科院分区：
文献类型：
--
作者：
Peter M. Finocchio;J. Doyle
与急流相互作用的热带气旋（TC）可以触发Rossby波包，放大下游的气流，但急流调节TC-急流相互作用的程度以及下游响应的发展仍不清楚。本研究使用25个COAMPS-TC模型的理想化模拟，以研究初始纬向急流的纬度和最大风速如何影响下游对转向TC的响应。在前5天的模拟，急流条纹和高压脊的形成紧接着下游的TC发生在低纬度急流比高纬度急流。这是由于在低纬度较弱的TC惯性稳定度，这促进了负的位涡平流的无旋流出沿着急流。局部增加喷流速度会降低TC极向的惯性稳定性，但不会深刻影响TC扰动喷流的能力。超过5天，最高纬度和最快的射流，具有最大的斜压增长率，表现出最高振幅的Rossby波和最迅速加强的表面气旋更远下游的TC。下游响应的这两种测量对速度的变化比对射流纬度的变化更敏感。停用冷凝加热后不久，TC触发Rossby波包，降低幅度和变化的下游流量高达3倍，相对于完全潮湿的模拟。这一结果强调了潮湿的非绝热过程的重要性，产生一个放大的下游响应，在7-10天内转向TC。
Recurving tropical cyclones (TCs) that interact with the jet stream can trigger Rossby wave packets that amplify the flow far downstream, but the extent to which the jet stream modulates TC–jet interactions and the development of the downstream response remains unclear. This study uses 25 idealized simulations from the COAMPS-TC model to examine how the latitude and maximum wind speed of an initially zonal jet stream affect the downstream response to recurving TCs. During the first 5 days of the simulations, the formation of a jet streak and a ridge immediately downstream of the TC occurs earlier on low-latitude jets than on high-latitude jets. This is due to weaker TC inertial stability at low latitudes, which promotes negative potential vorticity advection by the irrotational outflow along the jet. Increasing the speed of the jet locally reduces inertial stability poleward of the TC, but does not profoundly affect the ability of the TC to perturb the jet. Beyond 5 days, the highest-latitude and fastest jets, which have the largest baroclinic growth rates, exhibit the highest-amplitude Rossby waves and the most rapidly intensifying surface cyclones farther downstream of the TCs. Both measures of the downstream response are more sensitive to changing the speed than the latitude of the jet. Deactivating condensational heating, shortly after TCs trigger a Rossby wave packet, decreases the amplitude and variability of the downstream flow by up to 3 times relative to the fully moist simulations. This result emphasizes the importance of moist diabatic processes for generating an amplified downstream response to recurving TCs within 7–10 days.
影响因子：
8.9
作者：
C. Grams;H. Wernli;M. Böttcher;J. Čampa;U. Corsmeier;S. Jones;J. Keller;C. Lenz;L. Wiegand-
通讯作者：
C. Grams;H. Wernli;M. Böttcher;J. Čampa;U. Corsmeier;S. Jones;J. Keller;C. Lenz;L. Wiegand-
北太平洋热带、中纬度和极地扰动的相互作用导致 2007 年 10 月北美上空发生相关的极端天气事件
影响因子：
3.2
作者：
Bosart, Lance F.;Moore, Benjamin J.;Cordeira, Jason M.;Archambault, Heather M.
通讯作者：
Archambault, Heather M.