摘要：This study investigates the effects of horizontalresolution and surface flux formulas on typhoon intensity and structuresimulations through the case study of the Super Typhoon Haiyan (2013). Threesets of surface flux formulas in the Weather Research and Forecasting Modelwere tested using grid spacings of 1, 3, and 6 km. Increased resolution andmore reasonable surface flux formulas can both improve typhoon intensitysimulation, but their effects on storm structures differ. A combination of adecrease in momentum transfer coefficient and an increase in enthalpytransfer coefficients has greater potential to yield a stronger storm. Thispositive effect of more reasonable surface flux formulas can be efficientlyenhanced when the grid spacing is appropriately reduced to yield an intenseand contracted eyewall structure. As the resolution increases, the eyewallbecomes more upright and contracts inward. The size of updraft cores in theeyewall shrinks, and the region of downdraft increases; both updraft anddowndraft become more intense. As a result, the enhanced convective coreswithin the eyewall are driven by more intense updrafts within a rather smallfraction of the spatial area. This contraction of the eyewall is associatedwith an upper-level warming process, which may be partly attributed to airdetrained from the intense convective cores. This resolution dependence ofspatial scale of updrafts is related to the model effective resolution asdetermined by grid spacing.
