hirlam physics developments
DESCRIPTION
Sander Tijm Hirlam Project leader for physics. Hirlam Physics Developments. Overview. Results of this year Verification Shallow convection Turbulence and convection for mesoscale Tuning of synoptic scale model. Mesoscale Verification Surface Turbulence & shallow convection - PowerPoint PPT PresentationTRANSCRIPT
Hirlam Physics Developments
Sander TijmHirlam Project leader for physics
Overview Results of this year Verification Shallow convection Turbulence and convection for mesoscale Tuning of synoptic scale model
Hirlam physics developments
Mesoscale
Verification Surface Turbulence &
shallow convection Deep convection? Radiation
Synoptic scale EPS & boundaries Verification Surface (tuning) Turbulence Shallow convection Deep convection Radiation Wave drag
Results this year Hirlam physics in IFS (Convection, turbulence and
radiation, Sass, Rontu and Niemela) Moist CBR (Sass & Tijm) MSO/SSO (Rontu) Surface scheme (snow and forest, talk of Stefan after
this one) Sloping surfaces radiation (Senkova) Stable PBL (GABLS, De Bruijn, Perov & friends)
Snow on ice (Vihma) Lake model (Kourzeneva & Tisler) Urban characteristics (Baklanov & Mahura)
Moist CBR Impact on cloud water profiles
Moist CBR Impact on precipitation
Snow scheme
Verification Verification working group to check physics of
mesoscale model Cooperation with Aladin Focus on relatively normal weather, which is challenge
for physics List of cases and progress of work can be found on:
http://www.knmi.nl/~tijm/Verif/Verifworkg.html
Verification of models against observations Model intercomparison Baseline for future model improvement
Verification
Cloud top temperatures (Zingerle)
KF-RKREFObs
Entrainment/Detrainment
Overprediction of high clouds Too much deep convection, too little
convection of intermediate depth Too little entrainment (lowering of
updraft temperature) and/or detrainment (stopping updraft mass flux)
Can also be seen in shallow cumulus
Specific humidity profiles for ARM with LES (left) and Hirlam 1D using =z-1 and =0.00275
Shallow convection (De Rooy)
Mass flux profiles for LES (left) and =z-1 + =0.00275 (right)
Shallow convection
Massflux profiles for LES (left) and =z-1 + new (right) where depends on cloud depth and critical fraction
Shallow convection
qt profiles for ARM with LES (left) and Hirlam SCM (right) with =1/z and new formulation c
Shallow convection
EDMF scheme (Siebesma)
•Nonlocal (Skewed) transport through strong updrafts in clear and cloudy boundary layer by advective Mass Flux (MF) approach•Remaining (Gaussian) transport done by an Eddy Diffusivity (ED) approach
zinv
EDMF
h (km)
x(km)
0
5
1
Use LES to derive updraft model in clear boundary layer.
0
Updraft at height z composed
of those grid points
that contain the highest p%
of the vertical velocities:
p=1%,3%,5%:
EDMF scheme One scheme for boundary layer and cumulus convection Will be developed within AROME framework, as an
option Cooperation with ECMWF
After successful implementation in mesoscale model, incorporate in synoptic scale model to limit boundary effects
Surface developments New surface scheme (Gollvik) for synoptic scale
Extension of surface scheme with lake model (Kourzeneva)
Extension with improved description of snow on ice (Vihma)
Urban impact to be included (Mahura and Baklanov) Tuning of surface characteristics (Garcia)
Modeled temperature, sensitivity to lake depth(Flake model, Kourzeneva)
Tuning of syn. Hirlam Sytematic errors in synoptic scale Hirlam:
too much fog too many and intense small scale lows too strong convection dynamics feedback (noisy pressure
pattern) Overestimation of evaporation over sea may be an
important factor in the development of these phenomena, together with:
Vertical diffusion in stable and neutral conditions Deep convection parameterization
Tuning of syn. Hirlam
Small scale developments
Summary Many developments for turbulence, shallow and deep
convection, surface modelling. Shift of main effort towards the mesoscale physics Synoptic scale remains important, for mesoscale
boundaries and SREF Synoptic physics as close as possible to mesoscale
physics, to reduce boundary effects