Deutscher Wetterdienst status reportDeutscher Wetterdienst status report

Reinhold Hess

Silver Spring, 2006

19th North America-Europe Data Exchange MeetingSilver Spring, Maryland May 3-5, 2006

Reinhold Hess, 2

Deutscher Wetterdienst status report

Overview:• Events in NWP since the last report

• use of satellite radiances with 1D-Var (AMSU-A)• use of AMV of Meteosat 8 (and MTSAT)

• Research• AIRS/IASI with 1D-Var• Scatterometer (QuikSCAT)• Radio Occultation• LME: SEVIRI and ATOVS with 1D-Var• LMK: Radar reflectivities with LHN• 3D-Var

• Conclusion

Silver Spring, 2006

Reinhold Hess, 3

Global Model GME 40/40

Model System:

GME (Global Model): hydrostatic, icosahedral-hexagonal grid, mesh size ~40kmterrain following hyb. coordinate, 40 layers, bottom layer at 10 m, 7 soil layersforecast range: 174h initial dates 00, 12 UTC and 48h for 18 UTCprognostic cloud ice, prognostic sea ice

Analysis: OI, 3-hourly intermittent analysis, observation window +/- 1.5hobservations: conv., AIREP, AMDAR, ACARS, ATOVS (NOAA-15,16 and AQUA),

AMV (GOES E and W, GMS, Meteosat 5 and 7), PAOBMODIS-Winds, PSEUDO-tempscutoff: 2h30 (for forecasts)

Silver Spring, 2006

Reinhold Hess, 4

Assimilation of IFS Pseudo Temps

Data Coverage

Profiles of IFS/4D-Var Analyses (temperature, humidity and wind)as Temps for OI/GME

Assimilation one time per day for 0 UTCinto Main Analysis only

(operational since Dec 17 2003)

use of humidity profiles only above 700 hpa

Silver Spring, 2006

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Use of ATOVS with 1D-Var

Setup: • Level 1c ATOVS from UKMO (NOAA 15, 16 and AQUA)

(NOAA 18 in preparation)

• Channel Choice: AMSU-A 5-12 (HIRS deferred)

• Bias-Correction: UKMO-Style (scan angle and mass, A4 and A9)

• MW Rain/Ice-detection (Kelly and Bauer/ECMWF)

• Assimilation as SATEMS in OI (geopotential thicknesses, PWC)

(assimilate 1d-var analysis increments only)

• Retrieval of temperature only (humidity deferred)

• B-Matrix based on GME-Statistics (NMC-Method)

• Use of IFS forecasts above GME model top (10hPa)

Silver Spring, 2006

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• Significant improvement of conventional Routine (no Pseodo-Temps) with 1D-Var• 1D-Var (without PT) is comparable to Routine (with PT) for 0 UTC

500 hPa ANOC, 0 UTC, Routine, 1006 (conv. Rou), 1004 (1D-VAR)

Silver Spring, 2006

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500 hPa ANOC, 12 UTC, Routine, 1006 (conv. Rou), 1004 (1D-VAR)

• Significant improvement of conventional Routine (no Pseodo-Temps) with 1D-Var• 1D-Var (without PT) is lags behind Routine (with PT) for 12 UTC

Silver Spring, 2006

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500 hPA ANOC, 0 UTC, for Routine, 4638 (Pseudo+1D-VAR)

1D-Var (with PT) further improves compared to Routine (with PT) for 0 UTC

Silver Spring, 2006

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500 hPA ANOC, 12 UTC, für Routine, 4638 (Pseudo+1D-VAR)

1D-Var (with PT) is neutral compared to Routine (with PT) for 12 UTC

Silver Spring, 2006

Reinhold Hess, 10

Use of ATOVS with 1D-Var

Monitoring with routine GME available on Internet:http://www.dwd.de/en/FundE/Analyse/Assimilation/

> Monitoring

diurnal cycles of o-b differences are caused byassimilation of pseudo-temps one time per daybecause of slightly different inherent model climatesof GME and IFS/ECMWF

Silver Spring, 2006

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Use of AIRS/IASI

Status:• monitoring available• cloud detection implemented (S. English)• validation of channel selection (UKMO sample)• bias correction (mass and scan angle correction)• channel-based cloud detection implemented (T. McNally)

validation study at ECMWF

Next:• trial experiments (just started)• validation of retrievals and forecasts• preparation for IASI

Silver Spring, 2006

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collocation of AIRS-787 departures,MODIS visual cloud product,model clouds, and results of AIRS cloud detection

distributions of AIRS-787 first guess departuresfor visually cloud free and cloudy fovs

Validation study of channel selection at ECMWF

inconsitencies detected and clarified,e.g. visual cirrus does not affect lw CO2 band

visually cloud free sample has bias of 0.04 K,visually cloud affected sample has bias of -0.07K

Silver Spring, 2006

Alexander Cress

• Usage• extratropics over oceans; tropics over oceans and land

• IR above 1000 hPa • QI > 85

• WVcloudy above 400 hPa (both channels)• QI > 80; tropics > 85

• WVcloudy between 700 and 400 hPa (7.3 μm)• QI > 80 only on the Southern Hemisphere

• WVclear is not used• VIS below 700 hPa

• QI > 65 ; tropics: QI > 85

• FG check: asymmetric to remove negative OBS-FG bias

• Thinning: 1 wind per pre-defined thinning box (200 km;15 vertical layers).

Analysis and forecast impact of AMVs of Meteosat 8(generated at EUMETSAT)

Alexander Cress

Difference of the mean RMS increments between an analysis using Meteosat 7 and Meteosat 8 AMV winds

• Reduction of RMS by replacing Meteosat 7 AMV winds with Meteosat 8 wind data• Positive impact of Meteosat 8 AMV winds on the global GME analysis

Alexander Cress

NH

SH

TR

EU

forecast time h forecast time h

anco

ran

cor

Routine

Exp. 5344

Routine Routine

Routine

Exp. 5344 Exp. 5344

Exp. 5344

Routine with Meteosat 7 AMVs

Experiment with Meteosat 8 AMVs

replacing Meteosat 7

Anomalie correlation coefficient for 500 hPa geopotential height date: 2005111500 - 2005121500, 30 forecasts

Use of QuikSCAT DataQuikSCAT data 25 km resolution

date: 2004092709Used data JPL Rain Flag Used data KNMI Rain Flag

Silver Spring, 2006

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Use of QuikSCAT Data

Obs

bias: 0.80rms: 3.21cor: 0.66

All DataData with KMNI Rain Flag 0without outer zone and full bias correction

bias: 0.22rms: 2.06cor: 0.82

F G F G

Status:• monitoring available• KNMI rain flag• bias correction• test cases

Next:• more trial runs

Silver Spring, 2006

Obs -FG (All data, bcor) Obs - FG (OI data, bcor)

STDV Obs -FG (All data, bcor) STDV Obs -FG (OI_data, bcor)

Mean: 0.63

Mean: 1.85

Mean: 0.44

Mean: 1.48

• Data selection (KNMI rain flag) reduces Bias and Stdv. • Some rain contamination still present in tropics ?

Statistics for QuikSCAT wind speed Dez. 2004

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Use of Radio-Occultation Data (CHAMP)

Receiving Produkt from MPI-Hamburg(bending angles based on canonical transformation)

Monitoring since Jan 2004

bias and stddevof bending anglescompared to GME [%]

Work deferred until COSMIC data becomes availableSilver Spring, 2006

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LM (Local Model): non-hydrostatic, rotated latitude-longitude grid, mesh size 7kmterrain following hyb. coordinate, 40 layersforecast range: 78 for initial dates 00, 12prognostic cloud ice, prognostic rain

Model System:

Analysis: continuous nudgingobservations: conv., AIREP,AMDAR,ACARScutoff: 2h30variational soil moisture analysis

Local Model LM (LME)

Silver Spring, 2006

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MW rain/ice detection (Kelly/Bauer) as for GME

• Assimilation of 1D-Var retrievals with nudging analysis• Continuous nudging analysis requires 1D-Var within LM for topical background

Use of Radiances (SEVIRI/MSG and ATOVS) for LME with 1D-Var

Silver Spring, 2006

NWC-SAF scene analysis for IR/WV cloud detection

Status: Trial runs about to start

Model Domain LMK

LMK:• x = 2.8 km• 50 levels• t = 30 sec.• Tges = 18 h

– Initialised with LME every 3 hours

– Explicit simulation of deep convection

Silver Spring, 2006

Latent Heat Nudging of Radar Reflectivities for LMK

Silver Spring, 2006

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Minimisation in Observation Space rather than Model Space

Conventional 3D-VAR (MSAS, Model Space Assimilation System)solve:

(physical space assimilation system, dual space, observation space)

PSAS (OSAS, Observation Space Assimilation System)solve:

• more flexibility in definition of B• observation space smaller than model space !?!• minimisation costs become quadratic in number of observations

Development of PSAS (3D-Var)

Silver Spring, 2006

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Development of PSAS (3D-Var)

Adaptive Vertical Error Correlations for 1D-Var

(depending e.g. on vorticity)

Silver Spring, 2006

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Reinhold Hess, 28 Silver Spring, 2006

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Status and Plans

Conclusion:

• Operational: ATOVS/AMSU-A with 1D-Var and OI (substituting SATEMS)• Pre-operational: AMVs of MET-8 (substituting MET-7)• Operational Plans in

• ATOVS/AMSU-B• AIRS/IASI• QuikSCAT• Radio Occultation

• Prototype of PSAS/3D-Var (direct Assimilation of ATOVS, AIRS)• but also Interest in AIRS/IASI-Retrievals

Silver Spring, 2006

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Many thanks foryour attention!

Deutscher Wetterdienst status report

Silver Spring, 2006