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THIRD MEDIUM-TERM (2002-2004) RESEARCH PLAN FOR ALADIN
STATUS AT THE END OF OCTOBER 2003
« marching towards very high resolution and
continuous data assimilation
while preserving if not improving the current level of response to
operational problems »
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--- high priority, important and/or urgent action |
--- situation safe |
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--- intermediate priority or "medium-term" action |
--- situation not that bad |
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--- low priority or "long-term" action |
--- problems !!! |
COUPLING
An emerging priority Ü A lot of work performed
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Interaction with orography |
"Surface-pressure tendency" coupling "Orography" coupling |
STARTED Waiting |
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Spectral coupling |
Use of large-scale spectral information Interpolation of amplitude and phase-angle Combination with Davies'scheme Case studies and tuning |
IN PROGRESS STOPPED IN PROGRESS IN PROGRESS |
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Time-interpolation |
Further comparison of the present schemes |
DONE -> warning index |
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New prognostic variables |
Design of a strategy for new variables from physics Introduction whenever required |
Waiting |
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Towards higher resolution |
Pseudo-radiative scheme Two-way nesting Non-hydrostatic variables Case studies |
Waiting Waiting Waiting IN PROGRESS |
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Data assimilation issues |
Comparison of present choices Spectral coupling and 4d-var |
IN PROGRESS Waiting for 4d-var |
DYNAMICS
A huge step forward !
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Hydrostatic dynamics : improved semi-Lagrangian schemes |
Uniformly accelerated scheme Predictor-corrector (P/C) scheme |
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STOPPED (further studies not required) | |
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NH dynamics : three-time-level semi-Lagrangian (3TL) schemes |
Optimal choice of model variables P/C scheme |
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NH dynamics : two-time-level semi-Lagrangian (2TL) scheme |
Properties of P/C scheme Refinement in the choice of model variables Use of decentering |
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DONE : efficient and accurate NH dynamics available ! code cleaning and documentation now | |
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Bottom boundary condition (NH) & related discretisation problems |
Optimal discretisation General improvement of the current scheme |
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almost DONE refinements required | |
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Diabatic forcing) |
Strategy for the diabatic forcing Adaptation to the final choice of prognostic NH variables |
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STARTING | |
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Orographic forcing |
Optimal filtering of the orography Resonance problem in NH |
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Filters available and tested Resonance : solved | |
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Relaxation of the thin layer hypothesis |
Implementation and test in ALADIN Extension to NH |
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STOPPED : first solution coded and tested, second one (NH) considered, but no impact at present scales | |
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Radiative upper boundary condition |
Feasibility study : analysis, academic 2d tests Adaptation to ALADIN NH Control of the hydrostatic version |
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STARTED | |
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Horizontal diffusion |
Horizontal diffusion using semi-Lagrangian interpolators Gridpoint treatment of humidity |
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PROMISING RESULTS -> to be further tested and applied to NH | |
PHYSICS
Initial objectives :
Solving identified problems at the present operational resolutions and
going towards higher resolution : ~ 5 km
Ü
Now modified !
USE OF NEW PROGNOSTIC VARIABLES AND CHANGES IN CONCERNED SCHEMES
Convection |
Introduction of a prognostic convection scheme Management of the 4 new variables Validation over an extended set of situations Investigating problems in the triggering of convection Analysis of the closure and hysteresis problem |
in progress |
Microphysics |
Management of 2 or 3 new variables : condensed water Further analysis of the "Functional Boxes" approach Introduction / choice of a semi-complex microphysics Interface with convection Prognostic treatment of falling condensates or not? |
in progress in progress in progress waiting waiting |
Vertical diffusion, low cloudiness, PBL, ... |
Introduction of a prognostic TKE scheme (1 new variable) Interaction with other developments concerning PBL : * link between top of PBL fluxes and cyclogenetic activity * noise in shallow convection * PBL-height dependent mixing lengths * developments in the anti-fibrillation scheme * improvement of low-level cloudiness (diagnostic scheme) |
started in progress SOLVED started waiting DONE better vertical diffusion |
General problems |
Update of thermodynamics Consistency with the other parameterizations Interface with coupling, dynamics and data assimilation Consistency with regular physics Validation at various horizontal and vertical resolutions |
waiting waiting waiting waiting started |
IMPROVEMENT OF BASIC PARAMETERIZATIONS
Radiation |
Refinements of optical depths Move (choice, development) to an intermediate scheme |
IMPROVED in progress |
Orography |
Improved smoothing of very small scales Management of the extension (and coupling ?) zone Tuning of the envelope Better description of roughness length Investigation of feed-backs with other parameterizations Study of local circulations Development of new diagnostics |
DONE improved waiting waiting waiting waiting DONE |
Surface |
Parameterization of lakes Improved description of evaporation over sea Revisit of the z0h/z0m ratio over land Improved databases for soil and vegetation |
waiting waiting waiting in progress improved snow cover |
Simplified regular |
Tuning of diffusion Improved description of humidity Validation at high resolution Consistency with the "full" physics |
Evaluation via sensitivity studies at high resolution |
Physics / dynamics interface |
Introduction of the new variables Interaction with the predictor / corrector approach Interface with "externalized" parts of the physics |
STARTED |
VALIDATION
Case studies |
Identification and study of "strange behaviour" cases Selection and documentation of extreme situations Validation on a wider range of situations |
DONE waiting |
New observations |
Comparison to satellite data Comparison to radar or lidar data Interfaces to new field experiments |
in progress waiting in progress |
New methods |
Design of new scores or criteria Use of expert systems to identify fine scale structures |
waiting waiting |
DATA ASSIMILATION : METHODS
Main objectives for upperair assimilation
Prototype 3d-var á
Operational 3d-var á
Operational 3d-FGAT á
Prototype 4d-var
A lot of work, new ideas, significant progress, but a too ambitious program !
Modelisation of background / forecast errors
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Sampling methodology |
Evaluation of the different contributions to error covariances Ensemble analyses and forecasts with perturbed observations Singular vector approach |
in progress In progress waiting |
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Diagnostics |
Heterogeneity and anisotropy Time-dependence Nonlinear effects |
in progress in progress |
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Jb formulation |
Approaches based e.g. on diagonal blocks and wavelets |
in progress |
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New variables |
Taking into account new prognostic variables (NH, cloud water, ...) |
waiting |
Algorithmic aspects
3d-var |
Use of observations at the borders of the domain New minimization algorithms Design of an explicit spectral blending and combination with 3d-var Improvement of observation operators (vertical interpolations) Choice of the time-window for the selection of observations |
waiting waiting started waiting waiting biperiodicity Jk |
3d-FGAT |
Implementation of a 4d screening Choice of lateral boundary conditions Choice of the time-window |
DONE waiting waiting |
4d-var |
Maintenance of the TL/AD code (for various research purposes) Coding TL/AD of semi-Lagrangian schemes Definition of coupling strategies for the various elements Adaptation of Jc-dfi (to high resolution, to new variables) Improvement of simplified physics |
DONE waiting waiting waiting waiting |
Simplified physics |
Evaluation through sensitivity studies Evaluation and tuning at high resolution Solving incrementality problems Adapting observation operators to new variables |
done done waiting waiting |
A-posteriori validation |
Further tuning of statistics (observations + background) for 3d-var Extension of diagnostic tools to 4d-var |
DONE waiting |
TL/AD tools |
Maintenance of the TL/AD code (reminder) Use in the design of the TL/AD code (e.g. LBC, NH, new variables) Use to study nonlinearity problems (e.g. in simplified physics) Predictability studies |
waiting waiting done starting |
Var-Pack |
Watch |
starting |
Cycling
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Blending |
Maintenance of a reference version of dfi-blending Adaptation to the main changes in the model Development of double-nested blending Comparison of "dfi" and "explicit" blending for spectral fields |
DONE waiting waiting started |
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Assimilation cycle |
Investigating the various combinations between 3d-var, dfi and blending Combination with surface analysis or surface blending Moving to 3d-FGAT Maintenance of a reference version |
in progress in progress started waiting |
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Frequency of 3d-Var |
Evaluation through sensitivity studies |
waiting |
PREDICTABILITY
First work plan ready !
DATA ASSIMILATION : OBSERVATIONS
Work has started !
ODB |
Maintenance and documentation Development of new tools |
DONE OK |
Satellite data |
IASI / AIRS: Improved description of surface emissivity Raw ATOVS data : use of local data Cloudy ATOVS data : observation operator, Jb GPS SSM/I Profiler data |
in progress done ? waiting starting done |
Surface observations |
From the less difficult or most important ones to new ones: surface pressure, 2m-relative humidity, 10m-wind, ... |
in progress |
Aircraft data |
Use of local data |
in progress |
Radar |
Winds Reflectivities |
waiting starting |
Pre-analysed data |
Pseudo-TEMP for relative humidity : case studies Pseudo-TEMP for relative humidity : regular use Surface data bogus |
done waiting waiting |
Screening |
Evaluation for high-density data New data types Time window Time dimension PBL fields |
in progress waiting waiting 4D OK ? |
Space consistency of the quality control |
Combination with the use of the CANARI quality control Variational quality control |
waiting starting |
DATA ASSIMILATION : SURFACE
A too intermittent effort !
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Analysis of PBL fields, for * Diag-Pack * correction of soil fields |
Retuning of statistics (forecast and observation errors) Geographical dependent error statistics (orography, coasts, ...) Analysis of new fields (precipitations, visibility, cloudiness, ...) |
DONE Starting Started (precipitations) New tools for Diag-Pack |
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SST analysis |
Retuning Use of pre-processed satellite data |
ok DONE (sea-ice) |
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Snow analysis |
Retuning of statistics, for large and small scales Estimation of the vertical correlations for errors on snow depth Calculation and use of a snow mask derived from satellite data Use of pseudo-observations from local networks Analysis / correction of new fields (albedo) Improved climatological fields |
Restarting Starting waiting waiting To be used ! |
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Assimilation of soil |
Reduction of the horizontal heterogeneity of soil moisture Retuning and implementation in ALADIN Combination with dfi-blending Combination with 3d-var Moving to a variational assimilation Use of satellite data Improved climatological fields |
something DONE waiting waiting waiting In progress waiting To be used ! |
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Diag-Pack |
Improvements in observations operators (vertical interpolations) Use of aircraft, profiler, radar-wind data Diagnostics fields (smoothing, new ones) |
waiting In progress waiting |
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Quality control |
Retuning screening for surface observations |
waiting |
APPLICATIONS
Still one of the weak points of ALADIN, but the situation is not that bad
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POST-PROCESSING |
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§ forecast : new fields on demand |
DONE + |
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¨ research configuration (assimilation) : implementation |
NOTHING DONE |
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AVAILABLE TOOLS FOR OPERATIONS AND RESEARCH |
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ª re-launching the exchange of applications |
NOTHING DONE |
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¨ ensuring portability |
IMPROVEMENT |
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¨ design of a management procedure |
NOTHING DONE |
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INTERFACE TO DOWNSTREAM APPLICATIONS |
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¨ documentation of existing tools |
NOTHING DONE |
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STATISTICAL ADAPTATION |
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¨ more networking, within ALADIN and SRNWP |
? |
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DYNAMICAL ADAPTATION |
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ª further research required |
NOTHING DONE |
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MODEL TO SATELLITE APPROACH |
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§ a recent and promising tool |
IMPROVEMENT |
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DIAG-PACK |
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¨ enhanced exchanges with nowcasting teams |
OK |
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¨ further research required |
CONTROVERSIAL ! |
VERIFICATION
Another weak point of ALADIN (and not only of ALADIN)
Building a coordinated procedure for objective verification |
Definition of rules, implementation of the database Routine update of the database Improvements and diffusion of results |
STARTED NOT YET NOT YET |
Defining a verification procedure for high resolution forecasts |
Definition of a working group (modellers and forecasters) Use of satellite and radar data (precipitations) Safe exchange of local observations between ALADIN partners |
Nothing done STARTED Directors'level |