– Date of implementation/upgrade of the current system version: September 2022
– Whether the system is a coupled ocean–atmosphere forecast system: no
– Whether the system is a two-tier forecast system: yes
– Atmospheric model resolution: 0.9°x0.72° lon-lat, 96 vertical levels
– Ocean model and its resolution (if applicable): n/a
- 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
- 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
– Sea Surface Temperature (SST) specification:
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
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
– Hindcast period: 1991-2015
– Ensemble size for the hindcasts: 11 members for each year (total number of hindcasts 275)
– Method of configuring the hindcast ensemble: breeding vectors are used to create the initial perturbations (Toth, Kalnay, MWR 1997) and stochastic perturbed parameterization parameters (Ollinaho et al, QJRMS 2017) are partially activated to represent uncertainties associated with model formulation
– Forecast ensemble size: 41
– Method of configuring the forecast ensemble: the same as for hindcast ensemble but with different ensemble size
– Forecast ranges: 46 days for subseasonal forecast, 135 days for seasonal forecast
– Data format: GRIB2
– The latest day of a week when subseasonal forecasts for the next weeks/month become available: Friday
– The latest date when predicted anomalies for the next month/season become available: 14th of each month
– Method of construction of the forecast anomalies: anomaly = forecast - (hindcast climate)
– URL where forecast is available: https://seakc.meteoinfo.ru/en/forecasts/subseasonal-forecast
- Points of contact: Mikhail Tolstykh email: mtolstykh @ mail.ru ; Radomir Zaripov email: zaripov @ mecom.ru .