Nat. Hazards Earth Syst. Sci. Discuss., https://doi.org/10.5194/nhess-2018-333 Manuscript under review for journal Nat. Hazards Earth Syst. Sci. Discussion started: 2 January 2019 c Author(s) 2019. CC BY 4.0 License. Impacts of Horizontal Resolution and Air–Sea Flux Parameterization on the Intensity and Structure of simulated Typhoon Haiyan (2013) Mien-Tze Kueh1, Wen-Mei Chen1, Yang-Fan Sheng1, Simon C. Lin2, Tso-Ren Wu3, Eric Yen4, Yu-Lin Tsai3, Chuan-Yao Lin1 5 1Research Center for Environmental Changes, Academia Sinica, Taipei, Taiwan 2Academia Sinica Grid Computing Centre, Institute of Physics, Academia Sinica, Taipei, Taiwan 3Institute of Hydrological and Oceanic Sciences, National Central University, Taiwan 4Academia Sinica Grid Computing Centre, Academia Sinica, Taipei, Taiwan 10 Correspondence to: Chuan-Yao Lin (
[email protected]) Abstract. This study investigates the impacts of horizontal resolution and surface flux formulas on typhoon intensity and structure simulations through the case study of the Super Typhoon Haiyan (2013). Three different sets of surface flux 15 formulas in the Weather Research and Forecasting Model were tested using grid spacing of 1, 3, and 6 km. Both increased resolution and more reasonable surface flux formulas can improve typhoon intensity simulation, but their impacts on storm structures are different. A combination of decrease in momentum transfer coefficient and increase in enthalpy transfer coefficients has greater potential to yield stronger storm. This positive effect of more reasonable surface flux formulas can be efficiently enhanced when the grid spacing is appropriately reduced to yield intense and contracted eyewall structure. As 20 resolution increases, the eyewall becomes more upright and contracted inward.