| A two-dimensional cloud-resolving model is used to simulate torrential rainfall over northeast China in July 2013 and the simulated rainfall is compared with observed rainfall.The modeling data are further used to conduct the analysis of rainfall,to calculate the budgets of cloud,heat,water vapor and microphysics and to diagnose precipitation efficiency.The results show that the relative importance of fractional rainfall coverage and rain intensity in domain mean rain rate is time-dependent,in which the coverage is more important than rain intensity before 6 July,whereas it is less important after 6 July.Rainfall is mainly associated with condensation.The secondary cruclations associated with rainfall are measured by perturbation kinetic energy and its tendency is mainly determined by the conversion from perturbation available potential energy to perturbation kinetic energy.Precipitation is defined as thepercentage of rainfall over rainfall source,which is budget dependent,but they are statistically correlated.Precipitation efficiency grows linearly when convective is weak while it bearly changes when convection becomes strong.The study also focuses on the diurnal cycle of rainfall,which is composited over 24 hours using modeLing data.The results reveal primary peak at hour 5,and secondary peaks at hours 15 and 19.The rainfall maximum at hour 5 is associated with maxima of rain intensity and fractional rainfall coverage as well as Liquid water and ice water paths,maximum transfer fron perturbation available potential energy to perturbation kinetic energy and centers of condensation and associated latent heat around the height of 4 km.The rainfall maximum at hour 5 is genrally phase locked with the precipitation efficiency maximum.At hours 15 and 19,domain mean rainfall peak corresponds to the peak of rain intensity.The ransfer fron perturbation available potential energy to perturbation kinetic energy is significantly weaker than that at hour 5,which are not maxima. |
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