page 1 hal ritchie and many collaborators recherche en prévision numérique (rpn) meteorological...
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Hal Ritchie and many collaborators
Recherche en Prévision Numérique (RPN)Meteorological Research Division, Science and Technology Branch
Expert Meeting on Upper Ocean-Atmosphere Interactions, Exeter, December 2009
Sea Ice and Air-Sea Surface Exchange: Impacts in the Canadian
Coupled Atmosphere-Ice Ocean Forecast System
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Collaborators• Research Division (RPN)
– Pierre Pellerin, Michel Valin, Djamel Bouhemhem, Greg Smith
• National Lab for Marine & Coastal Meteorology
– Hal Ritchie, Serge Desjardins
• CMC– Manon Faucher, Francois Roy, Bertrand
Denis (CMDN)– Lewis Poulin, Dominic Racette, Doug
Bender, Yves Pelletier, Mark McCrady (CMOI)
– Richard Moffet (A&P)
• Regional weather offices– Atlantic & Quebec Storm Prediction
Centres
– Newfoundland & Labrador Office
• Canadian Ice Service (CIS)– Tom Carrières, Paul Pestiau
• Fisheries and Oceans Canada (DFO)
– Maurice-Lamontagne Institute (IML)
• Denis Lefaivre
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1) Impacts in the Gulf of St-Lawrence fully coupled Atmosphere-Ocean- Ice forecast system
2) R&D Strategy to Expand and Globalize the coupled system.
Outline:
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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 (GSL) forecast system: • Initiated 13 years ago by the Maurice Lamontagne Institute (DFO)
and Recherche en Prévision Numérique (EC) • Between January and March the GSL is nearly entirely ice covered • Ice conditions can change very rapidly• Coastal weather is strongly affected by the ocean conditions. • During the ice period, both systems are particularly interdependent.• To improve atmospheric forecasts (icing, clouds, fog,…)• To improve ocean-ice forecasts (ice, currents, temperature, waves…)• To improve services: GSL is a 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);
• Thermodynamics: 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
Page 1204/11/23 Page 12
Mont-Joli, 06 Feb. 2008
GEM Coupled Observations
Operational implementation
Fully Coupled system VS Operational GEM (48 hours forecast)
GEM Operational(Uncoupled)
~ 24 hours
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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 • 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 Service, Coast-Guard, Department National Defence
Operational Coupled Atmosphere-Ocean-Ice system Gulf of St. Lawrence
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1) Impacts in the Gulf of St. Lawrence fully coupled Atmosphere-Ocean-Ice forecast system
2) R&D Strategy to Expand and Globalize the coupled system.
Outline:
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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 Partnership
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 recommended by an inter-departmental advisory panel to become a partner in the development of an operational Canadian coupled atmosphere-ocean-ice data assimilation and modelling capability
Global Coupled System
4 years later: • A MOU among 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
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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