Model Resolution Dependency of the Maximum Intensity of Tropical cyclones and its development speed

In recent years, although tropical cyclone (TC) intensity forecast has been improved, there still has room for improvement. For example, while the National Hurricane Center official 48-h track forecast error has decreased about 50% between 2000 and 2010, the intensity forecast error over the same period has remained virtually unchanged (Rogers et al. 2013). Elsberry et al. (2007) reported that the rapid intensification (RI) is difficult to forecast. In addition, Kaplan and DeMaria (2003) show that 31% of all TC, 60% of all hurricanes, 83% of all major hurricanes, and all category 4 and 5 hurricanes underwent RI at least once during their lifetimes in the Atlantic Ocean. TC simulated by a model with high-resolution is stronger than that with coarser resolution (Murakami and Sugi 2010; Manganello et al. 2012). Using Nonhydrostatic ICosahedral Atmospheric Model with 3 types horizontal grid spacing (28, 14, and 7km), the authors conduct one-year experiments on the K computer provided by the RIKEN Advanced Institute for Computational Science. The results revealed that in the higher resolution experiment, TC intensity and its developing speed are stronger and faster than the coarser experiment. Both of these tendencies are consistent with the previous studies. The authors are going to examine the environmental variables and TC structure associated with TC developing process, and report these results.