Internal structure of ex‐Typhoon Phanfone (2014) under an extratropical transition as observed by the research vessel Mirai

Abstract

AbstractThe internal structure of Typhoon Phanfone (2014) undergoing “extratropical transition” over ocean was captured from the research vessel Mirai. The observed time series from world first shipboard polarimetric weather radar and frequent radiosonde launches revealed both dynamic and thermodynamic structure simultaneously in detail for four phases: cirrus shield, warm front, precipitation core, and western flank. To the east of the low‐pressure center, a warm front developed along the midlatitude baroclinic zone. In the eastern vicinity of the center, remnants of the warm core worked to enhance precipitation through convergence and frontogenesis against cold ambient air. This frontogenesis and related latent heating/cooling are suggested to maintain/enhance convection in these phases. In contrast, the warm core suppressed convection in the northern/western vicinity of the low‐pressure center.