improvement of the edmf scheme using kain fristch approach for meso-nh and arome improvement of the...
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Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
Improvement of the Eddy-Improvement of the Eddy-Diffusivity Mass Flux scheme Diffusivity Mass Flux scheme
using Kain-Fritsch approach for using Kain-Fritsch approach for Meso-NH and AROMEMeso-NH and AROME
CNRM/GMME/TURBAU
Julien PERGAUD, Sylvie MALARDEL,Valery MASSON
July 2006, 3rd
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
Introduction : EDMF scheme and purpose of our work
1/ Description of improved EDMF scheme– Equations for the Updraft Model– Definition of Lateral Mass Exchanges
– Closure Assumptions
2/ First Results for different study cases – Eurocs/ARM– Bomex
Conclusion : Work in progress and questions
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
Introduction
• Updraft starting from the ground– Dry BL – Dry BL and
shallow Cu– Sc BL (not
tested yet)
• Use of conservatives variables
EDMF Scheme
• EDMF scheme Soares et al,2004
TurbulenceConvection schemeSoares et al,2004
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
IntroductionEDMF Scheme :Results Eurocs/Arm (Malardel,Auguste)
'θw'EDMF L
'rw'EDMF tEDMF Rc
LES Rc
'θw'LES L
LES Rc
'θw'LES L
'rw'LES t
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
IntroductionEDMF Scheme : Results Bomex (Malardel,Auguste)
EDMF Rc'θw'EDMF L
'rw'EDMF t
LES RcLES Rc
'rw'EDMF t
'θw'LES L 'rw'LES t
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
IntroductionEDMF Scheme : improvement
Soares et al,2004
Continuity of mass flux
defintion
Better definition of entrainmentdetrainment
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
• Eq for w
• Eq for conservative
variables
Description of EDMF improved scheme
DEz
M
u
u
DφφEz
Mφ
w²M
EbaB
z
ww
1/ Equations for the updraft model
EDMF
KFB
w and MF equationsthe fractionnal updraft area
• Eq for the Mass flux
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
• Entrainment and detrainment in clouds are defined as in the KF formulation (Kain & Fritsch,1990):
2/ Definition of Lateral Mass Exchanges
Updraft-Cloud Zone
Limit between Updraft and environmentD
EE
ENVIRONMENT
Description of EDMF improved scheme
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
• Entrainment and detrainment in clouds are defined as in the KF formulation (Kain & Fritsch,1990):
2/ Definition of Lateral Mass Exchanges
Limit between Updraft and environment
Updraft-Cloud ZoneMaximum
updraft part detrainable to environment
ENVIRONMENT
Description of EDMF improved scheme
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
• Entrainment and detrainment in clouds are defined as in the KF formulation (Kain & Fritsch,1990):
2/ Definition of Lateral Mass Exchanges
Updraft-cloud Zone
Maximum environmental
part entrainable to the updraft
Limit between Updraft and environment
ENVIRONMENT
Description of EDMF improved scheme
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
• Entrainment and detrainment in clouds are defined as in the KF formulation (Kain & Fritsch,1990):
2/ Definition of Lateral Mass Exchanges
Updraft-cloud Zone
Updraft-environmental Mixture Zone
Limit between Updraft and environment
ENVIRONMENT
Description of EDMF improved scheme
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
• Entrainment and detrainment in clouds are defined as in the KF formulation (Kain & Fritsch,1990):
2/ Definition of Lateral Mass Exchanges
ENVIRONMENT
Updraft-environmental Mixture Zone
Mu
Updraft-Cloud Zone
BuoyantAir
HeavyAir
BuoyantAir
HeavyAir
Mt
Description of EDMF improved scheme
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
• Entrainment and detrainment in clouds are defined as in the KF formulation (Kain & Fritsch,1990):
2/ Definition of Lateral Mass Exchanges
ENVIRONMENT
Updraft-environmental Mixture Zone
EE
MuBuoyant
Air
HeavyAir
Updraft-Cloud Zone
BuoyantAir
HeavyAirD
E
Description of EDMF improved scheme
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
• KF formalism : E and D depends on v between environment and updraft
where with
- f(x) is a gaussian type distribution with f(0)=f(1)=0,
- c is the critical mixed fraction and the environmental mass fraction linked to the buoyancy
- Ro is the cloud Radius
2/ Definition of Lateral Mass Exchanges
χc
χf(χ)dχΔMtE0
1
1χc
χ)f(χ)dχ(ΔMtD
0/ RcMM etrut 2.0etrc
Description of EDMF improved scheme
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
2/ Definition of Lateral Mass Exchanges
dnL
MCE
E )1(
upL
MCD
D )1(
• From the ground to the Condensation Level, entrainment and detrainment are defined as in Lappen & Randall ,2001:
Lup and Ldn are the downward and upward BL89 mixing lengths
is the fractionnal updraft area.
In Lappen & Randall (2001) CE =1.0 and CD =1.5
This formulation needs diagnosed
Link with the turbulence
Description of EDMF improved scheme
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
3/ Closure assumptions
e
w'θ'θθ
sLLu
e
w'r'rr
sttu
• Initialisation of the parcel characteristics using Soares et al (2004)
with =0.3
• Moreover the mass flux at the ground is defined as :
sMss eCM3
2
where CMs corresponds to a fractionnal updraft area
defined for each study case
Description of EDMF improved scheme
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
First Results for different study cases1/ Eurocs/ARM
Evolution of Mean rc (kg/kg)
LES 1 D
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
First Results for different study cases1/ Eurocs/ARM
Profile of Mass flux, Entrainment and Detrainment averaged between 8 and 9 hours
Mass Flux Entrainment Detrainment
LCLLCL
LCL
sMss eCM3
2 09.0MsC
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
First Results for different study cases1/ Eurocs/ARM
1D Results
Average between8 and 9 hours
Evolutionof flux over 15 hours
LES Results
Average between8 and 9 hours
Evolutionof flux over 15 hours
'θw' L 'θw' L
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
First Results for different study cases1/ Eurocs/ARM
LES Results
Average between8 and 9 hours
Evolutionof flux over 15 hours
'rw' t
1D Results
Average between8 and 9 hours
Evolutionof flux over 15 hours
'rw' t
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
First Results for different study cases2/ BOMEX
LES 1 D
Evolution of Mean rc (kg/kg)
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
First Results for different study cases2/ BOMEX
Profile of Mass flux, Entrainment and Detrainment averaged between 8 and 9 hours
Mass Flux Entrainment Detrainment
LCL LCLLCL
sMss eCM3
2 05.0MsC
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
First Results for different study cases2/ BOMEX
'θw' L
'rw' t
LES Results
Average between5 and 6 hours
1D Results
Average between5 and 6 hours'rw' t
'θw' L
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
Conclusion : Work in progress and questions
The next stages in our work will be to
• Improve the closure asumption : surface mass flux
•Assess the sensibility of the scheme to different parameters : a and b in the w equation, CE and CD, and Ro
• Test the scheme with others cases : dry Bl or Sc Bl
• Implement the scheme in AROME and test in 3D runs
,...),,'',( CINCAPEwefM vs
Improvement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROMEImprovement of the EDMF Scheme using Kain Fristch approach for Meso-NH and AROME
Conclusion : Work in progress and questions
Some questions are interesting
• Must we use a prognostic approach to have a better view of the convection?
for example
• Links with deep convection, 3D runs ?
w²M
EbaB
z
ww
t
w