The Canadian Numerical Weather Prediction System: Present and Future Gilbert Brunet Recherche en Prévision Numérique (RPN) Meteorological Research Branch Meteorological Service of Canada Environment Canada Québec, Canada Thursday, November 1, 2001, CAS 2001 meeting, Annecy, France

Introduction u The main mandate of the Meteorological Research Branch (MRB) is to improve the operational Numerical Weather Prediction (NWP) and data assimilation system at the Canadian Meteorological Center (CMC) of the Meteorological Service of Canada (MSC) u We have to integrate in the NWP system observation instrument systems that has a maximum impact on improving prediction skill, like satellites, and radar for very-short-range forecasts u Environmental Prediction: We have to couple our NWP system with ocean, hydrological and chemistry models

RPN - Recherche en Prévision Numérique Many major world-wide innovations l During 1960’s and 1970’s  Semi-implicit method, Robert-Kwizak  First integration of spectral model, Robert  Optimum Interpolation, Rutherford  Operational spectral model, Daley-Girard  Finite Element model, Staniforth-Daley l During 1980’s and 1990’s  Semi-Lagrangian technique, Robert et al.  First operational TKE PBL, Benoit et al.  Ultra-fast FFT’s (Cray,CDC), Temperton  First SI-SL fully non-hydrostatic model Tanguay, Laprise, Robert (later MC2)  Unified GEM (global, uniform or variable resolution), Staniforth, Côté, Gravel et al.  MC2 is internationally recognized for mesoscale modeling, Benoit et al.

Increasing computer power u Increasing computer power u 1960 ’s - Bendix G20, IBM370. u 1970’s: Control Data 7600, Control Data 176 u 1980’s: Cray 1S, Cray XMP-2/8, Cray XMP-4/16 u 1990’s: NEC SX-3/44, SX-3/44R, SX-4/64M2 and SX-5/32M2 u 2000’s: Requirement for a new contract & new HPC systems

Trend in skill

Different problems need different modeling approaches and physics ONGOING RESEARCH at RPN (in collaboration with Canadian and International Institutions) u Global predictions need an uniform space grid model with a good climatic balance between dynamics and physics (Collaboration with CCMA/Victoria) u Regional predictions need a variable space grid model with improved implicit physics, like Kain-Fritsch deep convection scheme (Collaboration with McGill U. and Cloud Physics/SMC,Toronto) u Montainous and high resolution predictions of precipitation need a non-hydrostatic and limited area model with explicit physics, like Kong-Yau. (Collaboration with Mesoscale Alpine Project (MAP), McGill U. ) u Environmental prediction needs to couple the NWP system with hydrology, and ocean, and chemistry and wave models. (Collaboration with York U., Dalhousie U., Waterloo U., McGill U., Atlantic and Ontario SMC/Regions and Canadian Space Agency) u Middle atmosphere capability for integrating Canadian space and ground-based measurements and chemical modelling activities, like ozone (Collaboration with York U. and Canadian Space Agency) u Multi-seasonal forecasting needs a low resolution model with a particular attention to surface forcing, like sea temperature and soil moisture (Collaboration with CCMA/Victoria and McGill U.)

Different problems need different modeling approaches and physics u Variational data assimilation, 3Dvar and 4Dvar, needs the development of highly sophisticated numerical tools that are tied closely to the model dynamics and physics u Adaptation to new computer architecture is highly model dependant. u Global Environmental Multiscale (GEM): An integrating concept, one tool for different problems. u Leader: J. Côté and S. Gravel

Physical Processes Leader: S. Bélair and J. Mailhot S. Bélair Surface Processes H E M G Solar Radiation Infrared Radiation Boundary-Layer Turbulence Deep Convection Stratiform Precipitation

Physics ( ) u Global model with a 35km resolution with an optimized Kain-Fritsch, Tremblay (Cloud Physics/SMC) phase mixed scheme and ISBA surface scheme that drives a continuous data assimilation cycle u Regional model with an optimized Kain- Fritsch and Tremblay (Cloud Physics/SMC) phase mixed scheme with a 10km resolution that drives a continuous data assimilation cycle

Non-hydrostatic modeling of a severe weather squall line in Oklahoma

Radar reflectivity of the squall line event

Cloud water/ice

Cloud water/ice Hydrostatic Non-Hydrostatic

Non-hydrostatic effect: important for timing?

Regional GEM Model (rough estimates for research)

GLOBAL GEM GRID AT 35km

An 35km global uniform resolution GEM with an improved physics and cloud package for the Meteorological Service of Canada Model Results A B C SAT(OBS) OP NEW SAT(OBS) OP NEW Outgoing longwave radiation for a 1-day forecast valid at 0000 UTC 2 November 2000 using the proposed high-resolution model configuration A) Mid-latitude synoptic-scale systems over North America: Better representation of cold frontal convection and of occluded cyclonic circulations B) Convective activity over South America: More widespread continental convective activity and better representation of low- level clouds C) InterTropical Convergence Zone: Better representation of convective activity and of a Typhoon over southeast Asia A B C

Global GEM Model (rough estimates for research)

4DVAR GEM Global Model (rough estimates for research)

Community Of Mesoscale Modeling(COMM) group Leader: R. Benoit u Community model (MC2) support is essential in order to partner effectively with universities and benefit from funds provided through Canadian Foundation Climate and Atmospheric Science ($ per year) u Community model would be configured to focus on region with potential active or extreme weather events at 1-3km horizontal resolution. u MC2 is worldwide recognized as one of the most computer efficient non-hydrostatic model

MC2 run at 2km horizontal resolution over Vancouver Island 17H forecast valid 26 June UTC. Near surface flow (arrows with scale in knots in lower left corner). Superimposed over topography (gray shades every 500m). Only one arrow every other grid point for each directions is displayed. (M. Desgagné) Configuration: 1500 x 1300 x 31; 2880 time steps of 30 sec (24H); 14 PEs SX5; total memory: 46 Gb, wall clock : 16 H, Flops rate : 29 Gflops

Limited-Area GEM Model for high resolution meteorology (2000km X 2000km) (rough estimates for research)

Coupled Modeling for Environmental Prediction Leader: H. Ritchie u RPN Environmental Prediction and Coupled Modeling group is supporting/conducting R&D based on coupling a variety of numerical prediction models u Now feasible due to advances in numerical modeling in various domains, together with advances in computer power. u Very high level of collaboration with international and Canadian university and institutions. We are the provider of the numerical modeling and computer expertise u High potential for Canadian Foundation for Climate and Atmospheric Science collaborations

Key projects u Atmosphere-hydrology Model (Waterloo U., IML, MAP, Ontario/MSC Region, …) u Regional Ocean Modeling and Prediction (Dalhousie U., BIO,IML,...) u 3-D ocean circulation models being coupled with MSC models for atmosphere-ocean prediction (Dr. Greatbatch, Dalhousie U.,...) u Coastal Modelling Systems for Storm surge forecasts (Atlantic/MSC region, Dr. Thompson, Dalhousie U.,...) u Atmosphere-wave Modeling (Atlantic/MSC Region,...) u St. Lawrence Estuary Models (IML) u Marine Environmental Prediction System: Coupled atmosphere/ocean/biology/chemistry ecosystem model to be developed for demonstration site for Lunenburg Bay, NS (Dalhousie U., Bedford Institute of Oceanography,...) u Extra-tropical hurricane transition (Dalhousie U., McGill U.,...)

26 Marine Environmental Prediction System (MEPS) u To establish demonstration site for Lunenburg Bay, NS. u Goal: interdisciplinary marine environmental prediction guided and tested using advanced observing systems. u Coupled atmosphere/ocean/biology/chemistry ecosystem model being developed.

The Dream

The Reality

Extratropical Transition - Examining mid latitude transition of hurricanes and typhoons. - Eventually to use two-way interactive atmosphere-ocean data assimilation and prediction system for direct modeling. EDED FLO 10km/60 levels Kuosym/Sundqvist (MC2, M. Desgagné) H Forecast of relative vorticity at 25m (frame every hour) COMPARE

2km/40 levels Kong&Yau (MC2, M. Desgagné) H Forecast of Relative Vorticity at 20m (frame every hour) COMPARE

Limited-Area GEM Model for high resolution meteorology (2000km X 2000km) (rough estimates for research)

Conclusion u Meteorological Research Branch used in general 40% of the computer resources u Climate Research Branch used in general 40% of the computer resources u Canadian Meteorological Center used in general 20% of the computer resources For ( ) the R&D strategy u Global NWP with a MESOGLOBAL GEM (35km) with a lid at the stratopause (1mb) with the Regional GEM physics package u Global NWP ensemble forecast with GEM-100km with an improved physics package u Collaborating with CFCAS to improved our Regional and Local NWP u Collaborating with CFCAS and other partners for Environmental Prediction (coupling with chemistry, hydrology and ocean)