Association between tropospheric temperature and tropical cyclone peak intensity over the North Pacific and North Atlantic

Abstract

As natural weather disasters, tropical cyclones (TCs) are destructive in proportion to their peak intensity. This study investigates the association of North Atlantic, western North Pacific, and eastern North Pacific TC peak intensities with tropospheric air temperature, respectively, by applying NCEP–NCAR and MERRA reanalysis data. Both the correlation between TC peak intensity and air temperature and the difference in air temperature between strong and weak TC peak intensity conditions reveal that significant cooling of the tropopause and upper-tropospheric warming are accompanied by strengthening TC peak intensity for North Atlantic TCs, suggesting an important effect of upper-tropospheric static stability on TC peak intensity. However, warming in the lower troposphere is associated with strong TC peak intensity for eastern North Pacific TCs, indicating a major effect of lower-tropospheric static stability on TC peak intensity. The peak intensity of western North Pacific TCs is mainly affected by vertical wind shear, not the atmospheric temperature.摘要台风作为一种灾害性天气, 其破坏性大小与自身强度有很大的关系. 因此, 本项研究利用NCEP–NCAR和MERRA再分析数据, 考查了北大西洋, 西北太平洋, 东北太平洋台风强度峰值与对流层温度的关系. 台风强度峰值与大气温度的相关系数, 以及极大和极小台风强度峰值下大气温度的差值, 共同显示: 北大西洋台风强度峰值受到对流层顶低温和对流高层增温的正向作用, 表明了对流高层稳定性对北大西洋台风强度峰值的重要作用. 但是, 东北太平洋台风强度峰值却受到对流低层增温的正向作用, 表明了对流低层稳定性对东北太平洋台风强度峰值的重要作用. 西北太平洋台风强度峰值较少受大气温度影响, 主要受到垂直风切变的作用.