Suppression of Tropical Cyclone Development in Response to a Remote Increase in the Latent Heat Flux over the Kuroshio: A Case Study for Typhoon Chaba in 2010

This study investigated the remote impact of an increase in latent heat flux (LHF) over the Kuroshio on tropical cyclone (TC) development, using a cloud-resolving model. A control run and a sensitivity experiment with Kuroshio's LHF artificially enhanced were performed for Typhoon Chaba in 2010. The TC development simulated in the sensitivity experiment was suppressed as compared with the control run. The sensitivity experiment demonstrated that eyewall convection and the associated TC secondary circulation were suppressed by a decrease in equivalent potential temperature (θe) around the eyewall through the lower θe penetration into the inner core region in the boundary layer. The dynamic features of the TC were also altered by the attenuated TC secondary circulation through the inhibition of the inward advection of the absolute angular momentum. The super-gradient tangential velocities in the inner core were smaller than those in the control run. Such thermodynamic and dynamic changes were remotely induced by the decrease in moisture import from the Kuroshio. Since the increased LHF facilitated the development of a surface low over the Kuroshio, the intensified low further accumulated the Kuroshio's vapor and suppressed low-level northeasterlies toward the TC, resulting in interrupting the moisture import into the TC.