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Development of the Canadian Coupled Atmosphere-Ice Ocean Forecast System. Pierre Pellerin and several collaborators Recherche en Prévision Numérique (RPN) Meteorological Research Division, Science and Technology Branch. CAS Technical Conference Korea, November 2009. - PowerPoint PPT Presentation
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Pierre Pellerin and several collaborators
Recherche en Prévision Numérique (RPN)Meteorological Research Division, Science and Technology Branch
CAS Technical Conference Korea, November 2009
Development of the Canadian Coupled Atmosphere-Ice Ocean Forecast System
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1) Demonstration project: - Scientific results: Development of the Gulf St-Lawrence forecast system A first operational fully coupled Atmosphere-Ocean-Ice
2) R&D Strategy to Expand and Globalized the coupled system.
Plan:
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Development of the Gulf St-Lawrence forecast system A first operational fully coupled Atmosphere-Ocean-Ice
Gulf of St. Lawrence
N. Atlantic
The Gulf of St. Lawrence forecast system: • Initiated 13 years ago by the Maurice Lamontagne Institute (DFO)
and Recherche en Prévision Numérique (EC) • Between January and March is nearly entirely cover of Ice • Ice conditions can change very rapidly• Coastal weather forecasts are very affected by the ocean conditions. • During the ice period, both systems are particularly interdependent.• To improve the atmospheric forecasts (icing, clouds, fog,…)• To improve the ocean-ice forecasts (ice, currents, temperature,
waves…)• To improve the services: Major Seaway• Users: EC, coast-guard, DFO, maritime transportation, DND• Very interesting laboratory: Semi-enclosed Sea
Circulation is controlled : • by tides, • exchanges with atmosphere, • runoff from land,• the seasonal ice cover, • and the inflow through the bounding
straits
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Models & Coupling strategy
• Atmosphere: Global Environmental Multi-scale (GEM):– Regional configuration LAM @ 15km - 2.5 km and 58 levels;
• Ocean: Gulf of St. Lawrence Model (ROM, Saucier et al. 2003):– 3D Ocean @ 5km and 73 levels; version 4.9.5 (5.2.2);– Sea-ice (dynamic - thermodynamic);
• Elastic-viscous-plastic (EVP) model (Hunke & Dukowicz, Los Alamos CICE model, 1997);
• Thermodynamic: Semtner, 1976;• Coupler OASISv3-Gossip (Valcke 2004)
Methodology
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AtmosphereOcean-Ice
Each: 600 seconds
IR and Vis flux, Humidity, Pressure, Winds, Precipitation, Temperature.
Heat and Vapour Flux IR flux .
15 kmtimestep=600s
5 kmtimestep=300s
Coupler
CouplerCoupling description
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Ice fraction48h forecast2 way coupled
Atmosphere-Ocean-IceAn interesting Case
Case: Particularly interesting given that the intense atmosphericcirculation that dramatically changed the Ice conditionsin only 48 hours was preceded by a cold and relatively quiet period.
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C
d)
A
C
0
20
40
60
80
%
Anticosti
Clouds
Clouds
Ice
Water
Ice Observation Forecast (coupled) Ice
Valid: 14/03/97 20 Z after 44 hours
Atmosphere-Ocean-IceAn interesting Case Ice Forecast
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Atmosphere-Ocean-IceAn interesting Case
Difference Air temp.Coupled - Uncoupled
Impact on surface air temperature
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Impacts on low level clouds (air-ocean exchanges)
Uncoupled Fully coupleda) b)
c)
WaterIce
Clouds
AVHRR
Nov
a-S
coti
a
New-Brunswick
P-E. I.
Cape-Breton
M. I.
CloudsoverIce
Ice
WaterIce
Ice
Atmosphere-Ocean-IceAn interesting Case
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Data:
• Hourly air & dew point temperature, surface pressure, cloud cover
• 6-hourly precipitation accumulation
Objective Evaluation (Surface observations)
44 stations
Operational implementation
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Impact on atmospheric variables
Winter 2008
Forecast hour
% Coupled System better (> 50%)
Operational implementation
TemperatureHumidityCloudsPrecipitationSurface pressure
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Surface temperature (TT)
Forecast hour
Dew point temperature (TD)
Forecast hour
Statistics for February 2008
UncoupledFully coupled
Operational implementation
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Summary: • EC and DFO have successfully developed a fully-interactive coupled
atmosphere-ice-ocean forecasting system for the Gulf of St. Lawrence (GSL)
• This system will become fully operational at the Canadian Meteorological Centre (CMC) this winter
• Results during the past year have demonstrated that the coupled system produces improved weather forecasts in and around the GSL during all seasons
– Shows that atmosphere-ice-ocean interactions are indeed important even for short-term Canadian weather forecasts
• Used by Canadian Ice services, Coast-Guard, Department National Defense
Operational Coupled Atmosphere-Ocean-Ice system Gulf of St. Lawrence
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1) Demonstration project: - Scientific results: Development of the Gulf St-Lawrence forecast system A first operational fully coupled Atmosphere-Ocean-Ice
2) R&D Strategy to Expand and Globalized the coupled system.
Plan:
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15
Canada requires ocean forecasts and information services for:
– Weather prediction– Sea ice prediction (e.g. CCG: seal hunt,
navigation)– Fisheries and aquaculture management– Increased understanding of biological field
observations– Attribution and mitigation of regional climate
change impacts– Risk assessment for extreme events (sea
level, waves, currents)– Search and Rescue, dispersion of pollutants
Global Coupled System
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Mercator-Canada Alliance
Summary: • In 2005 Environment Canada, Department of Fisheries and Oceans and
Department of National Defense recognized a common need for products and modeling capabilities that can be provided by an operational global coupled atmosphere-ocean-ice data assimilation and prediction system
• MERCATOR was selected by an inter-departmental advisory panel to become partner for the development of an operational Canadian coupled atmosphere-ocean-ice data assimilation and modelling capability
Global Coupled System
4 years later: • A MOU between the three departments is now in place: Research,
Development and Implementation of Operational Coupled Atmosphere-Ocean-Ice Assimilation and Prediction Systems for Canada
• A letter of intent between Canada and Mercator put in place– Collaborations and Exchanges underway– The current operational ocean model of the Mercator-Ocean group
has been installed in Canada and is now used as common research system between DFO-EC
• An International Memorandum of Understanding (MOU) between Canada and the Mercator Océan is being drafted and is under review
– Main objective: Build a medium-long term perspective of collaboration between the two groups
Page 17
Core Projects
Atmosphere
Ice-Ocean
Data Assimilation
Observations
Models
Atmospheric Forecasts
Products
Data Assimilation
Observations
Models
Project 1:Project 1: Atm-Ice-Ocean Coupling (models and data
assimilaton)
Project 2:Project 2: Ice-Model
Project 4:Project 4: Ice Data Assimilation
Ice-ocean Forecasts
Products
Project 3:Project 3: Ocean Data Assimilation and Ice-Ocean Forecasting
Global Coupled System
Project 1: Gulf St-Lawrence
Atm.-Ocean-IceShort termHigh-Resolution
Project 3: Great-Lakes
Atm.-Lakes-IceShort termHigh-Resolution
Project 2: ArcticAtm. – IceShort term forecastsHigh-Resolution
ORCA025
Project 4: Global
Page 1904/22/23 Page 19
Mont-Joli, 06 Feb. 2008
GEM Coupled Observations
Operational implementation
Fully Coupled system VS Operational GEM (48 hours forecast)
GEM Operational(Uncoupled)
~ 24 hours