No abstract

In this study, a revised prognostic cloud fraction scheme for atmospheric models is proposed and its performance is evaluated with a diagnostic cloud fraction scheme. A revision is proposed through a direct linkage between hydrometeors in the cumulus parameterization scheme and the amount of predicted cloud fractions. Cloud fractions that are determined via the prognostic cloud fraction scheme appear to be more realistic than those determined via a diagnostic cloud fraction scheme when both are compared with satellite data. In a medium-range forecast test bed, the biases of large-scale features such as temperature, geopotential height, and mean sea level pressure are moderately reduced when the prognostic cloud fraction scheme is used.

No abstract

No abstract

To investigate the structure of latent heating rate during different stages of mesoscale convective system (MCS) over the Korean Peninsula, a four nested domain Weather Research and Forecasting (WRF) model simulation with two‐way nesting method has performed. Advanced physics options from the Korean Integrated model physics are considered for simulation. Latent heating rate associated with condensation, evaporation, deposition, sublimation, freezing and melting process is computed based on different microphysical process using WRF double moment (WDM6) microphysics scheme. During the development/mature stage of the convective system, the warming associated with latent heat release by condensation is dominant below 400 hPa, and deposition above 500 hPa. The maximum contribution of warming processes from condensation, cloud nucleation, graupel accretion, and ice, snow deposition is evident. Cooling processes from rain, cloud evaporation followed by graupel, and snow melting are also noticed. Major updrafts associated with ascent of air parcel and large hydrometeor distribution is apparent along with downdrafts in the lower levels. In the dissipating stage, the cooling due to latent heat absorption by evaporation below 600 hPa and melting around 600 hPa are dominant. Contribution from cooling processes is dominant with major downdraft motion in the lower levels corresponding to the hydrometeor fall velocity. Dominant positive (negative) total latent heating provided (restrained) the energy for convection during developing and dissipating stages of system. Varied distribution of total cloud hydrometeors in different stages is apparent. Consistency between cloud hydrometeors, net heating rates, major upward (downward) motion and corresponding rainfall in developing (dissipating) stages of MCS is noticed. Model simulated latent heating (WDM6) profiles are consistent with computed moisture source and sink terms (ERA5).