2Dmodel in arpifs framework

1
2D-model in arp/ifs framework

• Same code as the complete 3D-model
• Few modifications driven by the LMAP key
• Setup (geometry)
• SL scheme
• Developped by the NH Aladin team
• Also some utilisations within Arome (Squall line)

2
Running the 2D-model (3 steps)

• Step 1 to prepare an Aladin/Arome file ACADFA
  facilities-
• Step 2 run the model
• Step 3 Post-processing FLUX facilities-

3
ACADFA (many versions)
ACADFA
finit
Run
src
Makefile Source files
.exe namelist
Output file
4
The different steps of ACADFA

• Set up internal constants
• Read namelist
• Set-up of namelist-deductible variables
• Temp from brunt-Vaissala frequency
• Pressure and level coefficients from dZ,Temp, Ref
  pressure
• Prepare output file (frame of the fa file)
• Write grid-point data
• Compute orography (from the def of the hill)
• Write constant fields
• Write 2D spectral data
• Compute surf pressure from interpolation of ref
  pressure over the hill
• Write 3D spectral data
• Write other fields with constant values in general

5
some namelist variables of Acadfa

• IDGUX (CI) IDGL (CIE), IFLEV
• INSMAX meridional truncation
• ZDELY, ZDELZ
• LMPHYS, LREASUR
• LNHDYN
• LMAP
• IPOSITION (position of Hill), ZWIDTH, ZHEIGHT
• ZT00, ZP00, ZU00,

6
Run a 2D case

• Nothing special providing the good file except
• LmapF, RCORI_ACAD (coriolis for academic) in
  nemgeo
• Tune or not the sponge (mountain waves absorbing
  layer at the top)
• Nproma-ndgl (namdim)

7
Flux facilities (post-processing for academic
cases)

• An ensemble of sources able to read fa 2d outputs
  and to make ascii files
• Then can be plotted with usual graphics tools

8
Ex in Arome 2D squall line

• To test Microphysics and 1D TKE in Arome
• Some tuning of Acadfa to put a prescribed profile
  (T, Q, U) coming from an observed RS
  horizontal homogeneity.
• Some prescribed values during the run (a cooling
  during a limited period of time and on a bounded
  layer, some idealized values of surface fluxes),
  still in the code under key
• LSQUALL key (NAMMNH)

9
2D Academic Squall Line TKEmicrophysics (Yann
Seity, feb 2004)

Theta-theta0
Vertical velocity
Relative wind
Cloud
humidity
Sum hydro
TKE
10
2D Academic Squall Line TKEmicrophysics Yann
Seity feb 2004
AROME(7.5s) (8h) AROME (30s)
11
Concluding remarks

• A tool developped by dynamicians
• But should interest also the physicians to test
  for ex the importance of advection for some
  processes or some phys-dyn interactions in a
  simplified framework