LACE DA working days 28-30 September 2010, Ljubljana Local data assimilation system in Slovenia

LACE DA working days28-30 September 2010, Ljubljana

Local data assimilation system in Slovenia


Facts

• 4.4 km, 43 levels

• 439*421 points / 1931.6 * 1852.4 km

• Aladin cy35t1

• ALARO 3MT

• Timestep: 180s

• 3h ARPEGE LBC


Observations

• All OPLACE observations, except METOP and NOAA-19

• local NON-GTS SYNOP data

• No assimilation of SYNOP T2m and RH2m in 3DVAR


SMS assimilation suite


ODB / bator

• Merge of locally prepared obsoul and OPLACE for conv

• Created by subbases: conv amdr geow wpro sats sevb

• Fix in BATOR to avoid crash in case of no observations selected by lamflag

• Blacklisting not modified (from Hungary)


Screening & minimization

• Constant bias correction: VARBC tested, but not yet sufficiently validated

• NITER=70, NSIMU=80

• B matrix computed for July 2007 (~ 450 forecast differences), (downscaled) ensemble method

• REDNMC=1.3 (not tuned yet)


Verification

2m RH and T assimilation?

FF 700

Z 700

T 850


Problems

• “Packing bug”

– Negative Ts at some grid point

– Disappears if fields not packed (NVGRIB=0)

– Reproducible on some clusters, on others not

– Final solution: not pack surface fields (~10 % increase in file size)


Developments I• LSAF Albedo


Developments II• Snow assimilation (CANARI + LSAF)


Near future tasks

• Production suite + visualization and verification in operations

• Validate VARBC

• Improve observational usage

• Estimate/tune observational and background errors

• Add CANARI snow analysis

• Test and validate 3 hour RUC


Longer term

• Assimilate aircraft data, collected by a radar in Ljubljana airport (not really AMDAR)

• Test IASI and probably use it (will have 1py in 2011 - 2012)

Documents

LACE DA working days 28-30 September 2010, Ljubljana Local data assimilation system in Slovenia