Dynamics and Variability of Northern Hemisphere Storm Tracks

根据这一奖项，张博士将研究中纬度风暴路径的动力学及其与州基本大气流动的关系。他的目标是了解是什么驱动了风暴路径位置和强度的季节性和年际时间变化。这项研究建立在他以前工作的基础上，并受到观察到的对仲冬太平洋风暴路径的抑制的推动。这项研究包括四个推动力。前三个重点是在给定的基本状态下如何影响涡旋发展的具体机制；第四个集中在分离和理解风暴路径涡通量对基本状态的影响。具体地说，PI希望调查(1)基本态切变对风暴路径斜压源的影响，特别是对来自亚洲大陆的高层扰动的影响；(2)波传播变化引起的变率模式；(3)凝结加热对风暴路径的影响；(4)风暴路径的幅度和位置与大气低频变率之间的关系。在这项研究中，PI将使用多种工具，包括观测数据分析、全球环流模式(GCM)的数值模拟和理想化模式。第四个推力将涉及风暴路径模式和驻波模式的耦合。这项研究很重要，因为风暴路径的位置和强度直接影响区域天气。此外，需要更好地了解风暴路径行为，以预测气候变化可能导致的潜在变化。

Under this award, Dr. Chang will investigate the dynamics of mid-latitude storm tracks and their relationship with the basic state atmospheric flow. His goal is to understand what drives the seasonal and interannual time variations in the position and intensity of storm tracks. The study builds on his previous work and is motivated by the observed suppression of the of the Pacific storm track in mid-winter. The research consists of four thrusts. The first three focus on how specific mechanisms affect eddy growth in a given basic state; the fourth concentrates on isolating and understanding the effect of storm track eddy fluxes on the basic state. Specifically, the PI wishes to investigate (1) the effect of the basic state shear on the baroclinic sources of storm tracks particularly the effect on upper-level perturbations coming off the Asian continent; (2) the modes of variability due to wave propagation variations; (3) the effect of condensational heating on storm tracks; and (4) the relationship between the amplitude and the location of storm tracks and low-frequency variability of the atmosphere. For this study, the PI will employ a combination of tools including observational data analyses, numerical simulations with General Circulation Models (GCMs), and idealized models. The fourth thrust will involve the coupling of a storm track model and a stationary wave model.This research is important because the location and intensity of storm tracks have direct bearing on regional weather. Further, a better understanding of storm track behavior is needed to anticipate potential changes that might result from climate variations.