Further case studies using the 3 D -Var scheme for the ALADIN/H ungary model
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Transcript of Further case studies using the 3 D -Var scheme for the ALADIN/H ungary model
June 1- 4, 2004 ALADIN Workshop, Innsbruck, Austria
Further case studies using the 3D-Var scheme for the ALADIN/Hungary model
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Further case studies using the Further case studies using the 33DD-Var scheme for the -Var scheme for the ALADIN/HALADIN/Hungaryungary modelmodel
Steluţa Alexandru
András Horányi
June 1- 4, 2004 ALADIN Workshop, Innsbruck, Austria
Further case studies using the 3D-Var scheme for the ALADIN/Hungary model
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3D-Var formulation for ALADIN/HU model3D-Var formulation for ALADIN/HU model
The cost function is sum of:The cost function is sum of:
bJ
bTb xxBxxxJ )()(2
1)( 1
oJ
oTo yHxRyHx )()(2
1 1
background termbackground term
observation termobservation term
Background error covariance matrix:
NMC method
Background Background
information:information: 6h forecast6h forecast
Observations available:
SYNOP + TEMP
June 1- 4, 2004 ALADIN Workshop, Innsbruck, Austria
Further case studies using the 3D-Var scheme for the ALADIN/Hungary model
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Case studiesCase studies
The “inversion” case (December 27, 2002)
The “snow” case (January 7, 2003)
June 1- 4, 2004 ALADIN Workshop, Innsbruck, Austria
Further case studies using the 3D-Var scheme for the ALADIN/Hungary model
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12h forecast24h forecast
The “inversion” case (December 27, 2002)The “inversion” case (December 27, 2002)
3dvar
oper
observations
No big differences between the two models.No big differences between the two models.
26.12 12 UTC run
27.12 00 UTC run
June 1- 4, 2004 ALADIN Workshop, Innsbruck, Austria
Further case studies using the 3D-Var scheme for the ALADIN/Hungary model
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The “inversion” case (December 27, 2002)The “inversion” case (December 27, 2002)
height
(km)
oper
44
00
-6-6
3dvar
-4-4
22
00
The operational analysis showed a strong inversion, closer to reality.
The operational analysis showed a strong inversion, closer to reality.
analysis
27.12 12 UTC run
June 1- 4, 2004 ALADIN Workshop, Innsbruck, Austria
Further case studies using the 3D-Var scheme for the ALADIN/Hungary model
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The “inversion” case (December 27, 2002)The “inversion” case (December 27, 2002)
3dvar
operobservations
observations
LBC
first guess
3dvar analysisanalysis
• The first guess was too far from observations.
• Accurate information from the LBC.
• The first guess was too far from observations.
• Accurate information from the LBC.
analysis
27.12 12 UTC run
June 1- 4, 2004 ALADIN Workshop, Innsbruck, Austria
Further case studies using the 3D-Var scheme for the ALADIN/Hungary model
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height
(km)
-4-4
00
3dvar TLS
22
The “inversion” case (December 27, 2002)The “inversion” case (December 27, 2002)
44
00
-6-6
3dvar FG=ARP
ARPEGE first guess was closer to reality.ARPEGE first guess was closer to reality.
27.12 12 UTC run
analysis
June 1- 4, 2004 ALADIN Workshop, Innsbruck, Austria
Further case studies using the 3D-Var scheme for the ALADIN/Hungary model
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11 9
1614
9
914
13mm/12hmm/12h
806UTC-18UTC06UTC-18UTC
The “snow” case The “snow” case (January 7, 2003)(January 7, 2003)
1212
2424
oper
3dvar3dvar
1111
2323
Both models predicted the snowfall over Hungary.
Both models predicted the snowfall over Hungary.
June 1- 4, 2004 ALADIN Workshop, Innsbruck, Austria
Further case studies using the 3D-Var scheme for the ALADIN/Hungary model
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The “snow” case The “snow” case (January 7, 2003)(January 7, 2003)
850 hPa
3dvar3dvar
129129
oper
128128Both models predicted the low-pressure
system.Both models predicted the low-pressure
system.
24h forecast
June 1- 4, 2004 ALADIN Workshop, Innsbruck, Austria
Further case studies using the 3D-Var scheme for the ALADIN/Hungary model
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The “snow” case The “snow” case (January 7, 2003)(January 7, 2003)
-2.5 hPa/s
-2.8 hPa/s
3dvar3dvar 700 hPa700 hPa
oper24h forecast
Similar forecasts for other fields too.Similar forecasts for other fields too.
June 1- 4, 2004 ALADIN Workshop, Innsbruck, Austria
Further case studies using the 3D-Var scheme for the ALADIN/Hungary model
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ConclusionsConclusions
• The The 3D-Var procedure works properly. 3D-Var procedure works properly.
• But with some limitations.But with some limitations.
• It is important to have accurate lateral It is important to have accurate lateral boundary conditions.boundary conditions.
• The improvements introduced in the The improvements introduced in the analysis were lost after 6h.analysis were lost after 6h.
June 1- 4, 2004 ALADIN Workshop, Innsbruck, Austria
Further case studies using the 3D-Var scheme for the ALADIN/Hungary model
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THANK YOU FOR YOUR THANK YOU FOR YOUR ATTENTION!ATTENTION!