0
0
0
0
0
0
0
0
0
0
no
0
0
0
0
0
no
1
0
1
0
0
Nudging is available in ARPS, we (VITO) haven't used it so far but we plan to do that in the future.
1
0
0
0
1
Assimilation of TEMP and SYNOP data (u, v, T, q).
0
0
0
0
0
The objective analysis procedure
0
0
0
0
1
1
0
0
0
0
continuous 4D nudging assim. after Schraff (1996), for horizontal wind, Tpot, rel. hum. on all model levels and
surface pressure. Plus variational soil moisture analysis and SST analys. and snow height analysis.
1
0
0
0
0
Continuous 4D nudging assim. after Schraff (1996), for horizontal wind, Tpot, rel. hum. on all model levels and surface pressure. External snow height analysis.
1
0
0
0
0
Continuous 4D nudging assim. after Schraff (1996), for horizontal wind, Tpot, rel. hum. on all model levels and surface pressure. External snow height analysis.
1
0
0
0
0
continuous 4D nudging assim. after Schraff (1996), for horizontal wind, Tpot, rel. hum. on all model levels and
surface pressure. Plus variational soil moisture analysis and SST analys. and snow height analysis.
0
0
0
0
0
Interpolated reanalysis data of global model GME serve as lateral boundary conditions at least for the outermost-nest model
0
0
1
0
0
0
0
1
1
0
Canadian Meteorological centre operation 4D-Var
1
1
0
0
0
a) nudging of u,v,T,q,p(top) with adjustable form of coefficients
b) the adjoint version is experimental (see KAPITZA, H., 1991: Numerical Experiments with the Adjoint of a Nonhydrostatic Mesoscale Model. Monthly Wea. Rev. 119, 2993-3011)
0
0
0
0
1
intermittent data assimilation every 3h
on the icosaedral GME grid
0
0
1
0
0
1
0
0
0
0
continuous 4D nudging assim. after Schraff (1996), for horizontal wind, Tpot, rel. hum. on all model levels and
surface pressure.
1
0
0
0
0
continuous 4D nudging assim. after Schraff (1996), for horizontal wind, Tpot, rel. hum. on all model levels and
surface pressure. Plus variational soil moisture analysis and SST analys. and snow height analysis.
0
0
0
0
0
only in LME model,
not in LME_MH
1
0
0
0
0
1
0
0
0
0
0
0
0
1
0
1
0
0
0
0
0
0
0
0
0
1
0
0
0
0
nudging also used for 'Davies' type lateral boundary conditions
1
0
0
0
0
0
0
0
0
0
0
0
0
1
0
FDDA is a method of running a full-physics model while incorporating observations. Thus the model equations assure a dynamical consistency while the observations keep the model close to the true conditions and make up for errors and gaps in the initial analysis and deficiencies in model physics. The MM5 model uses the Newtonian-relaxation or nudging technique.
1
0
0
1
0
FDDA is a method of running a full-physics model while incorporating observations. Thus the model equations assure a dynamical consistency while the observations keep the model close to the true conditions and make up for errors and gaps in the initial analysis and deficiencies in model physics. The MM5 model uses the Newtonian-relaxation or nudging technique.
1
0
1
0
0
A continuous
(every model time step) dynamical assimilation is used where forcing functions are added to the governing model equations to gradually 'nudge' the model state toward the observations.
1
0
0
1
0
Dynamic assimilation every time step. Either observations, analysis fields or both can be used.
0
0
0
0
0
No
0
0
1
0
0
1
0
0
0
0
Nudging type of four-dimensional data assimilation scheme with observational data. The technique combines the analysis nudging and the observational nudging schemes. Nudging based on 3D fields produced by RAMS Isentropic Analysis (ISAN) pre-processor.
0
0
0
0
1
1
0
0
1
0
the model employs the Newtonian relaxation or 'nudging' technique in which one or more of the time-dependent variables are relaxed or 'nudged' toward observed values during the course of the simulation.
Reference: Sauffer, D.R. and N.L. Seaman. 1990. Use of four-dimensional data assimilation in a limited-area mesoscale model. PartI:experiments with synoptical-scale data. Mon. Wea. Rev., 118: 1250-1277.
1
0
0
0
0
The method used to optionally assimilate wind observations is based on the approach of Stauffer and Seaman (1994), where a nudging term is added to the horizontal momentum
equations (for u and v).
0
0
1
1
0
Currently 4D VAR at lower resolution, 3DVAR + latent heat nudging and moisture nudging at high resolution.
Highest resolution operational analysis 12 km every 3 h. 4 km under test.
0
0
1
0
0
1
0
1
0
0
4d-VAR under development