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

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.

颱風作為一種災害性天氣, 其破壞性大小與自身強度有很大的關係. 因此, 本項研究利用NCEP–NCAR和MERRA再分析資料, 考查了北大西洋, 西北太平洋, 東北太平洋颱風強度峰值與對流層溫度的關係. 颱風強度峰值與大氣溫度的相關係數, 以及極大和極小颱風強度峰值下大氣溫度的差值, 共同顯示: 北大西洋颱風強度峰值受到對流層頂低溫和對流高層增溫的正向作用, 表明了對流高層穩定性對北大西洋颱風強度峰值的重要作用. 但是, 東北太平洋颱風強度峰值卻受到對流低層增溫的正向作用, 表明了對流低層穩定性對東北太平洋颱風強度峰值的重要作用. 西北太平洋颱風強度峰值較少受大氣溫度影響, 主要受到垂直風切變的作用.