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Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier. COSMO-GM, Roma, 5.9.2011. Agenda. Motivation Status of the ARPA-SIM collaboration Domain and orography filtering Namelist choices Some results Summary Future. Motivation for COSMO-1. Operational target is for 2015 - PowerPoint PPT Presentation
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Federal Department of Home Affairs FDHAFederal Office of Meteorology and Climatology MeteoSwiss
Status of the COSMO-1 configuration at MeteoSwiss
Guy de Morsier
COSMO-GM, Roma, 5.9.2011
2 COSMO-GM, Roma / Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier
Agenda
• Motivation
• Status of the ARPA-SIM collaboration
• Domain and orography filtering
• Namelist choices
• Some results
• Summary
• Future
3 COSMO-GM, Roma / Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier
Motivation for COSMO-1
• Operational target is for 2015• Why increase the grid resolution?
- improve representation of forcing (e.g. topography, land use)
- better capture non-linear interaction between different scales (e.g.
convection)
- improve use of observing systems in the assimilation step
• Focus mainly on Alpine region and Alpine specific problems
4 COSMO-GM, Roma / Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier
Target: COSMO-1 suite in 2015
8x dailyCOSMO-1 +24 hours forecasts
1 km grid size, 100 layers
1040 x 700 grid pointsIFS boundary conditions 10 km grid size, 140 layers
4x daily
6 COSMO-GM, Roma / Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier
Status of the ARPA-SIM collaboration
√ Common domain• Test if a common configuration can be used and
a common evaluation of results operated• Nesting strategy
compare C-1 in C-7 with C-1 in C-2• Decrease damping in upper layers
cf. Wolfgang Langhans1)• Tune the orographic filtering to the stability of the
dynamics• Investigate the sensitivity to the asymptotic turbulent
length scale and the vertical level distribution
1) Convergence of numerical simulations of linear hydrostatic gravity wave, March 11, 2011
7 COSMO-GM, Roma / Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier
1) eXtra filter only for masked high Steps of Orography
Orography filtering (2 extremes)
Rhône V.
Rhine
COSMO-1COSMO-2COSMO-7
4 x Raymond filter + XSO1) 750m
8 COSMO-GM, Roma / Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier
Gradient of orography
a) NO filter, max.36°, mean 6°
b) Std filter, max.25°, mean 4.4°
c) 400m xso, max.20°, mean 4.2°
d) 300m xso, max.18°, mean 3.8°
Compare (CH) to:
COSMO-7: max.4°, mean 1.1°!
COSMO-2: max.15°, mean 2.8° near Mt Blanc
a) b)
c) d)
y
habs
x
habshgrad *5.0)(
10 COSMO-GM, Roma / Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier
Large Alpine Domain698 x 528 gridpoints
CPU of COSMO-2 * 4
300m filter: max. gr. 18°C-1 with 750m filter: 25°
COSMO-2: 15°
11 COSMO-GM, Roma / Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier
3“C-2
Orographic spectra
12 COSMO-GM, Roma / Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier
Namelist choicesBold for C-2 operational RED = C-1
Dynamics• time step (t=10sec, C-2=20)• advection (SL, Bott2, l3dstrang, lva_impl_dyn)• If possible NO horizontal diffusion• divergence damping (xkd=0.1/0.05/0.01)
best choice: • upper boundary condition (nrdtau=5/2)
*t: e-folding time for damping at the model top
Physics• turbulence (itype_turb=3)
13 COSMO-GM, Roma / Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier
COSMO-1 cases
A. Storm Carmen 12 November 2010with different orographic smoothingneeds horizontal diffusion (1 slide)
B. Convective case 29 May 2010with/without horizontal diffusiondifferent advection codes
C. Stratus case of 27 October 2009 without horizontal diffusion (no slides)
14 COSMO-GM, Roma / Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier
A. Energy spectra CARMEN (12.11.2010)
24h forecast (u, v, w)from 6 to 10km height
Similar results for smaller time steps
with hor. dif.
15 COSMO-GM, Roma / Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier
B. Convective case with COSMO-1
hd_corr_u_in=0.5 NO horizontal diffusion
16 COSMO-GM, Roma / Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier
Test with a modified advection (U. Blahak)
~ 15 m/s !
Maximum nur noch ~ 3 m/s !
17 COSMO-GM, Roma / Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier
B. Convective case with COSMO-1
NO horizontal diffusionUli Blahak modif. advection
18 COSMO-GM, Roma / Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier
B. Convective case with COSMO-1
001: Uli Blahak modif. advection
003: NO horizontal diffusion
002: with horizontal diffusion
[ m
3 ]
19 COSMO-GM, Roma / Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier
B. Convective case with COSMO-1
NOhorizontal
diffusion (hd)
NO hdbut with
UB modif.advection
Withhorizontaldiffusion
Time series of Max. vertical wind Max. horizontal wind
20 COSMO-GM, Roma / Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier
B. Convective case 29 May 2010
24h forecast (u, v, w)from 6 to 10km height
21 COSMO-GM, Roma / Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier
Summary
• Choice of the orographic filtering is not too bad considering the spectral evaluationbut depends on the model dynamics
• Stable run can produce meaningless values (horizontal wind) at some particular time
• Possible to run cases without horizontal diffusion
• The advection scheme has an impact on the results( more tests needed!)
22 COSMO-GM, Roma / Sept. 2011 / Status of the COSMO-1 configuration at MeteoSwiss Guy de Morsier
Future
• Set up an assimilation cycle for COSMO-1
• Regular runs from the assimilation cycle
• Evaluate against COSMO-2
• Need more test cases and/or case studies:- Convection- Stratus- Strong precipitation- Föhn