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Mesoscale model experience with UM at met.no by pengxiang

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									Mesoscale model experience
with UM at met.no
HIRLAM-ALADIN-MF miniworkshop 12/12/05
Dag Bjørge
NWP collaboration in Europe




                              Norwegian Meteorological Institute met.no
  Short version of UM history at met.no

• 2002: Met Office–met.no NWP collaboration
• 2003: UM 3km, S-Norway grid, forced by Met Office
  20km and Hirlam 10km
• 2004: UM 4km, Norway grid, forced by HL 10km
• 2005: ”UM4XL”, Norway/Sweden grid
• Nov2005: UM 1km, 3 small grids nested into UM4XL




                                   Norwegian Meteorological Institute met.no
How does it perform ?




                        Norwegian Meteorological Institute met.no
Temperature




              Norwegian Meteorological Institute met.no
Norwegian Meteorological Institute met.no
Norwegian Meteorological Institute met.no
How is the UM model set up ?

• Climate and parameter files from
  Met Office ”ancil generation” software
• LBC’s from Hirlam 10km, interpolation with
  ”hl2um” ( a met.no mixture of subroutines
  from UM and Hirlam )
• Some surface fields from Hirlam …
• Some fields from previous +12h forecast …



                                 Norwegian Meteorological Institute met.no
• 300 * 500 * 38 gridpoints,
• 4km resolution, 100s timestep
• Hourly postprocessing of surface fields, 3
  hourly pressure levels, 6 hourly model levels
• Boundary fields written out every 20 minutes
  for +8h to +21h, for nesting of 3 UM 1km grids
• Runs on 280 CPUs, at 00UTC and 12UTC
• 48h forecast in ~1h45min
• SGI Origin 3800 ( to be replaced next year )




                                     Norwegian Meteorological Institute met.no
What does it look like ?

• Quasi operational runs
• Different experiments
• Temperature problem solved (last week)




                                Norwegian Meteorological Institute met.no
The model chain at met.no

• The ”turbulence project” is used to
  describe the different models we now
  have available for forecasting at global
  to local ( airport ) scale.




                                   Norwegian Meteorological Institute met.no
Why a turbulence project ?
  ”På grunn av variable og vanskelige vindforhold
  bestemte kapteinen seg for å avbryte landinga. Da
  kom det et kraftig vindkast, og flyet smalt i
  bakken.”




                                       Norwegian Meteorological Institute met.no
• Orography and resolution ( ”Seven sisters” )




                                        Norwegian Meteorological Institute met.no
LBCs (~50km) for Hirlam20 and Hirlam10
at 3 hour intervals ( usually 6 hours old )




                                     Norwegian Meteorological Institute met.no
Hirlam10

• Starts from interpolated Hirlam20-analysis
• Boundaries ( frames ) from ECMWF
• Writes ”model dumps” / ”history files” every
  hour for nesting of Met Office Unified Model
  ( UM4 )




                                 Norwegian Meteorological Institute met.no
Hirlam10 and UM4




                   Norwegian Meteorological Institute met.no
UM 4km with three UM 1km grids




                           Norwegian Meteorological Institute met.no
The ”lifetime” of LBCs in a small grid




                              •30min intervals
                              Norwegian Meteorological Institute met.no
UM1

• Starts for all airports as soon as UM4 has
  reached it’s +21 hour forecast
• UM1 starts at UM4 +8h forecast, spins up
  for one hour
• Writes full model dumps at +9, +12, +15,
  +18 and +21
• The turbulence model called ”Simra” is
  then run for each of these instances


                                   Norwegian Meteorological Institute met.no
Operational cycles

• The model system as described is run
  twice a day at 00UTC and 12UTC
• Results are continously updated through
  the run, and can be studied as the
  forecast is produced




                                 Norwegian Meteorological Institute met.no
UM1, Sandnessjøen




                    Norwegian Meteorological Institute met.no
Example of product, inflight cone




                               Norwegian Meteorological Institute met.no
Example of product, inflight turbulence in
cross section




                                    Norwegian Meteorological Institute met.no
Some examples of different treatment of
precipitation in the different models




                                Norwegian Meteorological Institute met.no
”Precipitation shaddow”, Hirlam / UM




                                Norwegian Meteorological Institute met.no
Tromsø-area, Hirlam10 and UM4




                           Norwegian Meteorological Institute met.no
Structure of precipitation, HL20/10, UM4, radar




                                      Norwegian Meteorological Institute met.no
Ad hoc setup of UM for the Barents sea

• Example showing a ”polar low”




                                  Norwegian Meteorological Institute met.no
Polar low in UM 4km




                      Norwegian Meteorological Institute met.no
Hirlam10 og UM4




                  Norwegian Meteorological Institute met.no
UM4 +23h, mslp and wind




                          Norwegian Meteorological Institute met.no
Temperature problem ( solved last week )

• um505_thetamono_no.mf77
• A fix for the valley cooling problem. It is
  an active area of investigation and we
  may come up with alternative/better
  solutions, but this will hopefully work in
  the short term.




                                    Norwegian Meteorological Institute met.no
Norwegian Meteorological Institute met.no
Norwegian Meteorological Institute met.no
Norwegian Meteorological Institute met.no
Comparing Hirlam and UM

• Hirlam has been set up on exactly the
  same ( horizontal ) grid as UM4XL
• Hirlam version 6.4.1+
• H04 runs started in November on the
  met.no Linux cluster
• Some technical difficulties …
• Computer resources (SGI) : UM = 3 * HL



                                 Norwegian Meteorological Institute met.no
Heavy precipitation and flooding at the
western coast of Norway in November




                                  Norwegian Meteorological Institute met.no
Norwegian Meteorological Institute met.no
Hirlam 4km   UM 4km




                      Norwegian Meteorological Institute met.no
Hirlam 4km, 12h accumulated precip




                              Norwegian Meteorological Institute met.no
UM 4km, 12h accumulated precip




                             Norwegian Meteorological Institute met.no

								
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