R egional C ooperation for L imited A rea Modeling in C entral E urope ALARO Physics Neva Pristov (LACE area leader for physics)
ALARO � One of the physical parameterization package inside ALADIN/HARMONIE system � Characteristics: � multi-scale : parameterizations being as scale-independent as possible and giving physically consistent results over a wide range of model resolutions (in particular 10 km to 2 km) � consistency of all formulation , in particular within the 3MT framework for the macro physical parameterization of precipitations � a prognostic character of parameterizations, while they share the same information, approaches and level of complexity. � code stability, numerical efficiency and modularization � ALARO applications running at grey zone scales ALADIN Forecasters meeting, Sep 2014
9km 4km 6h precipitation amounts. Old CV 3MT shows a reasonable solution at both resolutions. Old convection shows a very bad pattern, especially at 4km mesh 3MT (‘grey-zone syndrome’). ALADIN Forecasters meeting, Sep 2014
ALARO-0 status � In the operational use in ALADIN countries � at, be, cz, hr, hu, po, ro, sk, si, tr, (po) model resolution between 8 km – 4 km, 2km � In EPS systems � ALADIN-LAEF, GLAMEPS, EPS at HMS � In climatological simulations � be, cz, se � Plans for a usage in � HarmonEPS convection-permitting ensemble system � multi model systems ALADIN Forecasters meeting, Sep 2014
Short history � Versions: � ALARO-0-without3MT (January 2007) � ALARO-0-with3MT (June 2008) � ALARO-0 baseline (December 2012) � ALARO-1 version1 (in preparation) � Workshops � Training Course ALARO-0, Mar 2007, Radostovice � ALARO-1 Working Days, Feb 2010, Budapest � ALARO-1 Working Days, Jun 2012, Ljubljana � ALARO-1 Working Days, May 2014, Vienna ALADIN Forecasters meeting, Sep 2014
ALARO-0 � governing equations for moist processes in barycentric system � radiation scheme NER (The Net Exchange Rate formulation) � turbulence: pseudo-prognostic TKE � moist physics: � Prognostic cloud water, cloud ice, rain and snow � 3MT(Modular, Multiscale, Microphysics and Transport) cloud and precipitation parameterization with prognostic microphysics unified for cloud water from resolved and unresolved processes; from the various condensation ‐ evaporation processes, sandwiched between updraft and downdraft � autoconversion, collection, evaporation/melting, freezing,.. � statistical approach for sedimentation of rain and snow � Horizontal diffusion: SLHD ALADIN Forecasters meeting, Sep 2014
ALARO-0 Organization of the physics time step 2 types of condensation 2 types of evaporation 1 radiation computation 1 microphysics computation ALADIN Forecasters meeting, Sep 2014
ALARO-1 � Improvements and adaptations of parameterizations for higher resolutions � Challenges: � Cost of radiation scheme � Complexity of turbulence, still with a need to “parameterize” � Advances in clouds and precipitation microphysics � Keeping complementary parameterization of precipitating convection ALADIN Forecasters meeting, Sep 2014
ALARO-1 developments (<10 km, down to 1 km) � Turbulence and shallow convection scheme TOUCANS � Radiation ACRANEB2 � Convection � Unsaturated downdraft scheme, � CSD (Complementary Subgrid Drafts): parameterization with a set of high resolution-specific features ascent, closure, triggering, evolution, deep convection � Cloud scheme � unified cloud treatment in radiation, shallow convection, thermodynamic adjustment and 3MT, � Microphysics, prognostic graupel � Rain drop size distribution � Geometry of cloud and precipitation ALADIN Forecasters meeting, Sep 2014
Impact on diurnal cycle average of mean hourly precipitation over the Czech area (11 realizations, Jun/Jul 2009) red - observations green - ALARO-0 “old” blue - ALARO-0 baseline Model starts rain early; Early decay as well; Too much precipitation in the morning; Lack of precipitation in the late afternoon and in the evening. ALADIN Forecasters meeting, Sep 2014
Impact on diurnal cycle average of mean hourly precipitation over the Czech area (11 realizations, Jun/Jul 2009) red - observations green - ALARO-0 “old” blue - ALARO-0 baseline magenta – ALARO-1step1 diurnal cycle of convection is improved ALADIN Forecasters meeting, Sep 2014
SAL verification Czech area 22 Jun – 7 Jul 2009 Structure component: 0.5mm/3hours horizontal axis Amplitude component: vertical axis Location: color (red – best L<0 0-1, green, blue, black for L>1) 10mm/3hours ALADIN Forecasters meeting, Sep 2014
ALARO-0 baseline version � grey-zone experiment defined by WGNE group (http://www.knmi.nl/samenw/greyzone/index.html) � cold-air outbreak case � convection develops over warmer sea surface � no big problem with orography � simulated at various resolutions: 16km, 8km, 4km, 2km and 1km over north Atlantic � run from 30 January 2010, 12 UTC, up to 36h � without and with parameterized moist deep convection � a very tough test-bed for multi-scale convection parameterizations alike 3MT ALADIN Forecasters meeting, Sep 2014
WGNE grey-zone test, ALARO-0, cloud cover at 24h range MODIS radiance observatio n 8km 2km 1km 16km 4km ALADIN Forecasters meeting, Sep 2014
WGNE grey-zone test, ALARO-0, 16 km 8 km 4 km 2 km 1 km 1h precipitation cumulated (30.1.2010 1231h), area between Faeroe and Orkney islands. The general structure of this short time precipitation pattern is kept, while more detailed solutions continuously appear with finer model resolutions. ALADIN Forecasters meeting, Sep 2014
WGNE grey-zone test, ALARO-0, 1h precipitation (30.1.2010 12+31h) 3MT activated 16 km 8 km 4 km 2 km 1 km 3MT disabled ALADIN Forecasters meeting, Sep 2014
2 options for mixing length computation False alarm for SW wind 14.12.2012 00:00 +34h Wind at 10 m pTKE AY pTKE EL1 Default z-dependent mixing length Mixing length dependent on TKE ALADIN Forecasters meeting, Sep 2014
2 options for mixing length computation False alarm for SW wind 14.12.2012 00:00 +34h Wind at 10 m pTKE AY pTKE EL1 ALADIN Forecasters meeting, Sep 2014
2 options for mixing length computation Vertical cross-section Temperature pTKE AY pTKE EL1 Default z-dependent mixing length Mixing length dependent on TKE TKE ALADIN Forecasters meeting, Sep 2014
Convection diagnostics � mixed layer CAPE � storm motion vector, vertical wind shear, relative helicity � lightning diagnostics � 4 different methods in test � diagnosed hail � vertical integral of graupel, � as an instantaneous flux maximum over a given period ALADIN Forecasters meeting, Sep 2014
Simulated radar reflectivity Lightning density � Type of the process � Location and timing can differ from reality ALADIN Forecasters meeting, Sep 2014
Severe freezing rain case end of January 2014 � ALADIN Forecasters meeting, Sep 2014
Severe freezing rain case ALADIN Forecasters meeting, Sep 2014
Severe freezing rain case - analysis Temperature BIAS Strength of inversion is diminishing during forecast ALADIN Forecasters meeting, Sep 2014
Severe freezing rain case ALADIN Forecasters meeting, Sep 2014
www.rclace.eu Operational products ALADIN Forecasters meeting, Sep 2014
Summary � ALARO parameterizations � past and future developments � testing, validation examples � multi-scale performance � Some strengths and weaknesses � realistic convection features � diurnal cycle of convective precipitation, � light precipitation, melting layer � Interpretation of the model results � (new) model – higher resolution – new challenges � some processed are more realistically described � Is the forecasting process able to cope with these changes? ALADIN Forecasters meeting, Sep 2014
Recommend
More recommend
