- Model physics:
Moist processes: The precipitation is produced by the large-scale and deep convective condensation processes under supersaturation conditions. Large-scale precipitation calculation is based on the diagnostically defined water content under the Marshal – Palmer drop size distribution function and prescribed drops concentration. The drop falling velocity is calculated in dependence of it’s diameter. Subsequent evaporation of large-scale precipitation in nonsaturated lower layer follows modified parameterization of Kessler (1969).
Radiation: The radiation fluxes calculation method is based on delta – Eddington two-stream approximation to transfer equation solution for short wave and long wave parts of spectra (Geleyn, Hollingsworth, 1979; Ritter, Geleyn, 1992). Cloud geometry is with two possible options: random and maximum overlap.
Planetary boundary layer: The vertical turbulent transport of moment, heat and moisture in the surface layer is described using Monin – Obukhov theory for different stratification type. Above, in PBL the K – theory is used. The modified Richardson number is applied in this procedure.
Land-surface: The surface processes include a simple moister and mass exchange parametrizations
– Source of atmospheric initial conditions: operational 3D-Var analysis of the Hydrometcentre of Russia for upper-air fields, OI analysis for screen-level temperature and humidity; simplified extended Kalman filter for soil moisture
SST predictions: ERA5 reanalysis is used as a climate. Sea surface temperature anomaly is defined as a deviation of current analysis data from daily climate, with anomaly decay time of 30 days. The current SST values are daily climate plus anomaly defined above