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Further case studies using the 3 D -Var scheme for the ALADIN/H ungary model

Further case studies using the 3 D -Var scheme for the ALADIN/H ungary model. Stelu ţ a Alexandru. Andr á s Hor á nyi. Background error covariance matrix: NMC method. Background information: 6h forecast. background term. Observations available: SYNOP + TEMP. observation term.

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Further case studies using the 3 D -Var scheme for the ALADIN/H ungary model

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  1. Further case studies using the 3D-Var scheme for the ALADIN/Hungarymodel Steluţa Alexandru András Horányi ALADIN Workshop, Innsbruck, Austria

  2. Background error covariance matrix: NMC method Background information: 6h forecast background term Observations available: SYNOP+TEMP observation term 3D-Var formulation for ALADIN/HU model The cost function is sum of: ALADIN Workshop, Innsbruck, Austria

  3. Case studies • The “inversion” case(December 27, 2002) • The “snow” case(January 7, 2003) ALADIN Workshop, Innsbruck, Austria

  4. 24h forecast 12h forecast observations oper 3dvar The “inversion” case (December 27, 2002) No big differences between the two models. 27.12 00 UTC run 26.12 12 UTC run ALADIN Workshop, Innsbruck, Austria

  5. oper 3dvar 2 4 height (km) 0 0 -6 -4 The “inversion” case (December 27, 2002) analysis The operational analysis showed a strong inversion, closer to reality. 27.12 12 UTC run ALADIN Workshop, Innsbruck, Austria

  6. observations observations first guess oper 3dvar analysis 3dvar analysis LBC The “inversion” case (December 27, 2002) analysis • The first guess was too far from observations. • Accurate information from the LBC. 27.12 12 UTC run ALADIN Workshop, Innsbruck, Austria

  7. 3dvar TLS 3dvar FG=ARP height (km) 2 4 0 0 -6 -4 The “inversion” case (December 27, 2002) analysis ARPEGE first guess was closer to reality. 27.12 12 UTC run ALADIN Workshop, Innsbruck, Austria

  8. oper 12 06UTC-18UTC 8 9 11 24 9 14 9 16 3dvar 14 13 mm/12h 11 23 The “snow” case (January 7, 2003) Both models predicted the snowfall over Hungary. ALADIN Workshop, Innsbruck, Austria

  9. oper 3dvar 128 129 The “snow” case (January 7, 2003) 850 hPa Both models predicted the low-pressure system. 24h forecast ALADIN Workshop, Innsbruck, Austria

  10. 700 hPa 3dvar -2.5 hPa/s oper -2.8 hPa/s The “snow” case (January 7, 2003) Similar forecasts for other fields too. 24h forecast ALADIN Workshop, Innsbruck, Austria

  11. Conclusions • The 3D-Var procedure works properly. • But with some limitations. • The improvements introduced in the analysis were lost after 6h. • It is important to have accurate lateral boundary conditions. ALADIN Workshop, Innsbruck, Austria

  12. THANK YOU FOR YOUR ATTENTION! ALADIN Workshop, Innsbruck, Austria

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