aladin consortium activities in data assimilation
DESCRIPTION
Aladin consortium activities in data assimilation. Claude Fischer & Andras Horanyi Stolen material from: Fatima Karbou, Pierre Brousseau, Loïk Berre, Olivier Caumont, Zahra Sahlaoui, Simona Stefanescu, Alex Deckmyn. Overview. Mainframe 3D-VAR application - PowerPoint PPT PresentationTRANSCRIPT
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
Aladin consortium activities in Aladin consortium activities in data assimilationdata assimilation
Claude Fischer & Andras HoranyiClaude Fischer & Andras Horanyi
Stolen material from: Fatima Karbou, Pierre Stolen material from: Fatima Karbou, Pierre Brousseau, Loïk Berre, Olivier Caumont, Zahra Brousseau, Loïk Berre, Olivier Caumont, Zahra Sahlaoui, Simona Stefanescu, Alex DeckmynSahlaoui, Simona Stefanescu, Alex Deckmyn
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
Overview Overview
1.1. Mainframe 3D-VAR applicationMainframe 3D-VAR application
2.2. Background error statistics: « B » Background error statistics: « B » matrixmatrix
3.3. Observations and OSEObservations and OSE
4.4. Arome prototypeArome prototype
5.5. Surface assimilationSurface assimilation
6.6. Plans and collaborationsPlans and collaborations
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
Mainframe 3D-VAR: example of Mainframe 3D-VAR: example of Aladin-FranceAladin-France
► Incremental 3D-VARIncremental 3D-VAR► Continuous assimilation cycle, 6 hour frequency, long cut-off Continuous assimilation cycle, 6 hour frequency, long cut-off
assimilation cycle and short cut-off production, coupled with assimilation cycle and short cut-off production, coupled with Arpège, Analysis=Model gridmeshArpège, Analysis=Model gridmesh=9.5km=9.5km
► Observations:Observations: Surface pressure, SHIP winds, Surface pressure, SHIP winds, synop T2m and RH2msynop T2m and RH2m Aircraft dataAircraft data SATOB motion windsSATOB motion winds Drifting buoysDrifting buoys Soundings (TEMP, PILOT)Soundings (TEMP, PILOT) Satellite radiances: AMSU-A, AMSU-B, HIRS, Satellite radiances: AMSU-A, AMSU-B, HIRS, Meteosat-8 SEVIRIMeteosat-8 SEVIRI QuikSCAT windsQuikSCAT winds Ground-based GPS zenital delaysGround-based GPS zenital delays
► Digital filter initialisation (non incremental)Digital filter initialisation (non incremental)
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
NON LINEAR AND OMEGANON LINEAR AND OMEGA BALANCESBALANCESIN THE ALADIN Jb (G. Faure, L. Berre)IN THE ALADIN Jb (G. Faure, L. Berre)
Qp
f
VfkVVPbal
2)(
)..(
2
22
0
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
Wind 850 hPa
+12h
~ 10 cases slightly >0
10 cases ~ neutral
1 case slighlty <0
NON LINEAR AND OMEGANON LINEAR AND OMEGA BALANCESBALANCESIN THE ALADIN Jb (G. Faure, L. Berre)IN THE ALADIN Jb (G. Faure, L. Berre)
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
Complex wavelets for LAM (A. Complex wavelets for LAM (A. Deckmyn)Deckmyn)
► Wavelets are (partially) localised in both grid point space and Wavelets are (partially) localised in both grid point space and Fourier space.Fourier space.
► Diagonalization of B in wavelet space can reproduce local variations Diagonalization of B in wavelet space can reproduce local variations in the structure functions and standard deviations.in the structure functions and standard deviations.
► Current work is focussing on reproducing 3D structure functions for Current work is focussing on reproducing 3D structure functions for different variables (Alex Deckmyn, Tomas Landelius, Loik Berre)different variables (Alex Deckmyn, Tomas Landelius, Loik Berre)
Standard deviations of Temperature errorat the lowest vertical level: from data (left)and from wavelet-B (right).
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
Daily small-ensemble Daily small-ensemble b’s and their filteringb’s and their filtering
b ENS 2 « RAW » b ENS 2 « FILTERED »
b ENS 1 « FILTERED »b ENS 1 « RAW »
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
Towards the assimilation of microwave surface sensitive Towards the assimilation of microwave surface sensitive channels from AMSU-A, AMSU-B & SSM/I over landchannels from AMSU-A, AMSU-B & SSM/I over land
F. KARBOU, F. KARBOU, EE. G. GÉÉRARD, F. RABIER, E. BAZILE, Z. RARD, F. RABIER, E. BAZILE, Z. SAHLAOUISAHLAOUI
Over land:
Only microwave channels that are the least sensitive to the surface are assimilated
Remaining uncertainties about land emissivity and skin temperature
Existing emissivity models : facilitate the assimilation of channels that receive a contribution from surface
The models need accurate input parameters hardly available at global scale
Need for alternatives to estimate the land emissivity New land surface emissivity parameterisations at Météo-France
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
The parameterisations (Karbou et al. 2006*):
1) Dynamically varying emissivities derived from only one channel for each instrument
2) Averaged emissivities over 2 weeks prior to the assimilation period
3) Averaged emissivities + dynamically adjusted skin temperature from one channel for each instrumentThis talk: Results from the dynamical approach (1)
* Karbou, F., E. Gérard, and F. Rabier, 2006, Microwave Land Emissivity and Skin Temperature for AMSU-A & -B Assimilation Over Land, Q. J. R. Meteorol. Soc. To appear.
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
RMS of error, AMSU-A, Glob, Period: 01 to 19 July 2005
Day of July 2005 Day of July 2005
Results: Results: Observation departures from first guess: Good impact Observation departures from first guess: Good impact on the on the observation operator observation operator performancesperformances
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
More low clouds in EXP
More Stratocumulus Less precipitating clouds
Less low clouds in EXP
Low cloudiness difference field EXP-CTR (from 31 24-hour forecasts 15 Aug-14 Sept
2005)
Results: Results: Impact on the analysis fields: Large impact on the Impact on the analysis fields: Large impact on the humidity fieldhumidity field
Results are given for AMSU-A & AMSU-B assimilation over land
Similar results are obtained with SSM/I over land
Great impact on the humidity and precipitation for both AMSU and SSM/I
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
Results: Results: Impact on the forecast skills: Positive impact on Impact on the forecast skills: Positive impact on humidity, humidity, temperature, temperature, geopotential heightgeopotential heightForecast scores / radiosondes (forecast-obs), SSM/I over land, 31 Forecast scores / radiosondes (forecast-obs), SSM/I over land, 31
cases, 15Aug-14Sep 2005cases, 15Aug-14Sep 2005analysis 24h forecast 48h forecast 72h forecast
Temperature
Geopotential h.
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
3D-VAR data assimilation in 3D-VAR data assimilation in MoroccoMorocco
►Aladin cycle : cy25t1Aladin cycle : cy25t1►Assimilation method :3d-var for upper Assimilation method :3d-var for upper
air fields / Canari O.I. for the surfaceair fields / Canari O.I. for the surface►Assimilation cycle : every 6 hoursAssimilation cycle : every 6 hours►Assimilation window :4,5h for short Assimilation window :4,5h for short
cutt off and 6h for long cutt offcutt off and 6h for long cutt off► Jb : standard NMCJb : standard NMC►Data used : conventional observationsData used : conventional observations
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
-0,15
-0,1
-0,05
0
0,05
0,1
0,15
0,2
0,25
01/11/2005 03/11/2005 05/11/2005 07/11/2005 09/11/2005
3D-VAR ADAP DYN
0
0,5
1
1,5
2
2,5
3
3,5
01/11/2005 03/11/2005 05/11/2005 07/11/2005 09/11/2005
3D-VAR ADAP DYN
Temperature 12h forecast against radiosondes (top:rms , bottom:bias)
Scores of temperature field (12h forecast) against radiosonde observations show :
Slightly positive impact for bias
Slightly negative impact on rms
Humidity at 900hPa versus ARPEGE analysis (red: dynamical adaptation & blue: 3DVAR)
The bias of humidity against ARPEGE analysis is reduced in low atmospheric levels (900 hPa) for all forecast ranges
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
Impact study of ATOVS raw radiancesImpact study of ATOVS raw radiances
Impact of AMSU-A is positive over areas with a lack of observations Impact of AMSU-A is positive over areas with a lack of observations (tropical band, Sahara, ocean)(tropical band, Sahara, ocean)
In mid latitudes, the impact of AMSU-A raw radiances is less marked In mid latitudes, the impact of AMSU-A raw radiances is less marked (conflict between several observation types). More sensitivity (conflict between several observation types). More sensitivity studies are needed to optimise the use of raw radiancesstudies are needed to optimise the use of raw radiances
P30 humidity field at 850hPa level
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
1D+3DVar assimilation scheme for 1D+3DVar assimilation scheme for reflectivitiesreflectivities
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
OSSE for reflectivities w/ Meso-NH/AladinOSSE for reflectivities w/ Meso-NH/Aladin
Simulated obs. with first guess (12 h MNH fcst)
Z (
dBZ
) @
20U
TC
Z (
dBZ
) @
18U
TC
Z (
dBZ
) @
19U
TC
Hu
(%)
+ 1
0-dB
Z c
onto
ur @
18U
TC
Simulated observations with « microphysical initialization »
Simulated obs. from 1D retrieval of (T,RH) + 3DVar
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
Summary & outlook for Summary & outlook for reflectivitiesreflectivities
Summary:Summary:► 1D retrieval able to correct for humidity,1D retrieval able to correct for humidity,► Quality control of data and obs. op. evaluation (M. Quality control of data and obs. op. evaluation (M.
Jurašek, LACE)Jurašek, LACE)► Implementation in Arome well advancedImplementation in Arome well advancedFuture work:Future work:► More 1D + 3D-VAR high resolution casesMore 1D + 3D-VAR high resolution cases► Perform cycling experiments,Perform cycling experiments,Collaborations:Collaborations:► Introduce beam blockage in obs. op. (G. Haase, Hirlam)Introduce beam blockage in obs. op. (G. Haase, Hirlam)
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
Arome prototype: a RUCArome prototype: a RUC
E : first guess Px : prévision échéance x
S0 : Arome surface file at t0 A : analyse
Cx : fichier de couplage à tx
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
Distribution of observations along Distribution of observations along the RUC (12 UTC - 0 UTC)the RUC (12 UTC - 0 UTC)
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
Cumul RR sur 3H : 00h-Cumul RR sur 3H : 00h-03h 03h
DyA RUC 1h
RUC 3h
00-03h
50 mm/3h
1 analysis
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
DyA RUC 1h
RUC 3h138 mm
03-06h
1 analysis
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
Surface assimilationSurface assimilation► O.I. scheme (CANARI) in Arpège and Aladin (CZ O.I. scheme (CANARI) in Arpège and Aladin (CZ
and MO)and MO)► Probably also tested soon in Aladin-FRProbably also tested soon in Aladin-FR► Same algorithm to be ported into the externalized Same algorithm to be ported into the externalized
surface scheme (SURFEX) ?surface scheme (SURFEX) ?► New system for 2D analysis (maybe soil, probably New system for 2D analysis (maybe soil, probably
PBL fields and spatialisation tool)PBL fields and spatialisation tool)► In FR: possibility to initialize fields from the coupled In FR: possibility to initialize fields from the coupled
soil/surface/hydrology system (SAFRAN)soil/surface/hydrology system (SAFRAN)► To be further discussed between Aladin and Hirlam To be further discussed between Aladin and Hirlam
partners at the next common workshop on surface partners at the next common workshop on surface (Toulouse, Dec. 11-13th)(Toulouse, Dec. 11-13th)
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
Plans for 2007 and outlookPlans for 2007 and outlook► B matrix and background std dev.:B matrix and background std dev.:
Errors of the day for screeningErrors of the day for screening Gridpoint maps of Gridpoint maps of b’s for minimizationb’s for minimization Filtering of the ensemble bg errors (low-pass)Filtering of the ensemble bg errors (low-pass) Native Aladin ensemble of analysesNative Aladin ensemble of analyses Derive from those an Arome ensemble forecastDerive from those an Arome ensemble forecast Wavelets (A. Deckmyn, Belgium; T. Landelius, Hirlam)Wavelets (A. Deckmyn, Belgium; T. Landelius, Hirlam)
► Algorithms:Algorithms: FGAT (with Hungary - LACE)FGAT (with Hungary - LACE) SL TL/AD and 4D-VAR in a nutshell (F. Vaňa, LACE)SL TL/AD and 4D-VAR in a nutshell (F. Vaňa, LACE) Incremental digital filtersIncremental digital filters Some kick-off on a simplified microphysics scheme for the mesoscale ?Some kick-off on a simplified microphysics scheme for the mesoscale ? Towards an integrated « Ensemble/Variational » data assimilation Towards an integrated « Ensemble/Variational » data assimilation
system; ETKFsystem; ETKF
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
Plans for 2007 and outlookPlans for 2007 and outlook► Observations:Observations:
SEVIRI radiances in Hungary (LACE) and Morocco SEVIRI radiances in Hungary (LACE) and Morocco (non-LACE) ?(non-LACE) ?
SEVIRI/CSR monitoring and bias correction; surface SEVIRI/CSR monitoring and bias correction; surface emissivity for IR SEVIRI channels (M. Stengel, emissivity for IR SEVIRI channels (M. Stengel, Hirlam)Hirlam)
Metop sensorsMetop sensors Work on radial radar wind obs. operator (T. Work on radial radar wind obs. operator (T.
Montmerle and C. Facchani)Montmerle and C. Facchani) Continuation on radar reflectivity obs. op. & retrieval Continuation on radar reflectivity obs. op. & retrieval
methods (M. Jurašek, LACE; G. Haase, Hirlam)methods (M. Jurašek, LACE; G. Haase, Hirlam) Microphysics modules for HIRS/IASI (M. Stengel, Microphysics modules for HIRS/IASI (M. Stengel,
Hirlam)Hirlam)
Thank you for your Thank you for your attentionattention
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
AMSU-A and AMSU-B (F. Karbou):AMSU-A and AMSU-B (F. Karbou):
AMSU-A and AMSU-B: temperature and humidity soundings• polar orbiting satellites: NOAA (15, 16, 17, 18), AQUA, MetOp• 20 channels: 23 to 190 GHz• scanning angle from -58° to +58° with V and H polarisation
Tb contaminated by surface conditions:Information about surface T and
Height of maximum sensitivity(depends also on scan and humidity content)
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
4 different approaches are compared
Several assimilation experimentsOver periods in 2005
Control run: operational model
Emissivities: - Atlas 2000 - Atlas 2005
Emissivities: dynamical computation
Emissivities: Atlas 2000 + estimation of Ts
Best choice so far:
-Atlas : risk for bias
-Dynamical comp.: risk for noise
New configurations tested for the surface
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
Compute surface emissivity by inverting the RT equation:
)),((
),(),(),(),(
TTs
TTpTp
Atlas 2000 Monthly global maps at 23, 31, 50, 89 and 150 GHz for February 2000
Atlas 2005
Monthly global maps for nadir at 23, 31, 50, 89 GHz from 01 through 20 March 2005+ parametrisation of (Karbou 2005) to take into account the scanning angle
Dynamical comp.
Emissivity computed for each meteorological situation for channel 1 AMSU-A (23GHz) and AMSU-B (89 GHz). These emissivities are attributed to the other channels without extrapolation.
New configuration for the surface
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
Emissivity, AMSU-B, channel1, operational
Emissivity, AMSU-B, channel1, atlas2005
Zürich 9th-12th, 2006 EWGLAM/SRNWP meetings
Comparison of obs-guess without bias correction, 22 March through 4 April 2005
150 GHz 183+/-1 GHz
183+/-3 GHz
183+/-7 GHz