In the 2019 tropical cyclone season in the western North Pacific, Typhoons FAXAI and HAGIBIS made landfall in Japan while keeping the intensity, resulting in serious disasters. This study addresses the influences of an increasing trend and variations in the upper ocean heat content above 26°C (tropical cyclone heat potential: TCHP) from January 1982 to June 2020 on FAXAI and HAGIBIS. TCHP underneath FAXAI and HAGIBIS in 2019 was higher than the climatological mean except for a part of mature phase of HAGIBIS due to HAGIBIS-induced sea surface cooling. TCHP significantly increased with the interannual oceanic variations (IOVs) in the subtropical (15°N-20°N, 140°E-150°E) and midlatitude (30°N-35°N, 130°E-140°E) areas where FAXAI and HAGIBIS intensified or kept the intensity. From an empirical orthogonal function (EOF) analysis of TCHP, we demonstrate that the leading three EOF modes of TCHP explain approximately 76.8% of total variance, but the increase in TCHP along the tracks of FAXAI and HAGIBIS particularly in the early intensification of HAGIBIS cannot be explained only by the IOVs included in the leading three EOF modes but rather by the warming trend irrespective of the IOVs.

在北太平洋西部的2019年热带气旋季节，台风FAXAI和HAGIBIS在保持强度的同时登陆日本，造成了严重的灾害。这项研究解决了1982年1月至2020年6月高于26°C的上层海洋热量含量增加趋势和变化（热带气旋热势：TCHP）对FAXAI和HAGIBIS的影响。由于HAGIBIS引起的海面降温，2019年FAXAI和HAGIBIS下的TCHP高于气候平均值，除了部分HAGIBIS成熟期。在亚热带（15°N-20°N，140°E-150°E）和中纬度（30°N-35°N，130°E-140°E）的年际海洋变化（IOV），TCHP显着增加FAXAI和HAGIBIS加剧或保持强度的区域。根据TCHP的经验正交函数（EOF）分析，