Transcript Toward a Seamless Process for the Prediction of Weather and Climate: On the Advancement of Sub-seasonal to Seasonal Prediction WWRP Gilbert Brunet TTISS, September 2009, Monterey.

Toward a Seamless Process for the Prediction of
Weather and Climate:
On the Advancement of Sub-seasonal to Seasonal
Prediction
WWRP
Gilbert Brunet
TTISS, September 2009, Monterey
Forecasting-system improvement at ECMWF
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Toward A Seamless Process for the Prediction of Weather and
Climate
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A collaborative effort between the WMO Programs
World Weather Research Programme(WWRP)THORPEX and World Climate Research Programme
(WCRP) on the advancement of sub-seasonal to
seasonal prediction;
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A white paper was prepared by a joint WWRPTHORPEX/WCRP team comprised of: Gilbert Brunet,
Melvyn Shapiro, Brian Hoskins, Mitch Moncrieff,
Randal Dole, George Kiladis, Ben Kirtman, Andrew
Lorenc, Rebecca Morss, Saroja Polavarapu, David
Rogers, John Schaake and Jagadish Shukla.
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Proposed Joint Research Objectives
between WCRP and WWRP
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Seamless weather/climate prediction with Multi-model
Ensemble Prediction Systems (MEPSs)
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The multi-scale organisation of tropical convection and its
two-way interaction with the global circulation
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Data assimilation for coupled models as a prediction and
validation tool for weather and climate research
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Utilization of sub-seasonal predictions for social and
economic benefits
Seamless weather/climate prediction with Ensemble Prediction
Systems(EPSs)
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Terms of reference for collaboration between TIGGE and
CHFP must be establish for experimentation and data
sharing for sub-seasonal to seasonal historical forecasts (
weeks to season) including the required infrastructure.
Development and use of ensemble based modeling methods
in order to improve probabilistic estimates of the likelihood
of high-impact events.
The requirements for both ensemble prediction methods and
greatly increased spatial resolution imply substantial future
requirements for computational power and for data storage
and delivery capacity.
Subseasonal prediction:
tropical influence
Z500
Wintertime,
NCEP reanalysis,
1979-2003
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PR
Composites of Z500 and tropical PR in PHASEs 3 and 7
Subseasonal prediction: the mid-latitude
response to MJO
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A simplified general circulation model (GCM)
Four hundreds monthly forecast with different initial
conditions
Idealized MJO Phase 3 forcing anomaly
Aknowledgements to Hai Lin
GZ500 mean anomaly response forecasted with the simplified GCM
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Composites based on NCEP reanalysis (GZ500)
Average response
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GZ500 standard deviation of forecasted anomalies
Day 11-15 standard deviation:
two first EOFs explain 43%
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• Regression to wind at 250hP initial conditions shows that
strength and latitudinal position of Pacific jetstream will
significantly modulate the forecasted response to MJO Phase 3.
• The tropical interaction with the global mid-latitude circulation is
an essential ingredient for successful subseasonal prediction.
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The multi-scale organisation of tropical convection and its twoway interaction with the global circulation
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Collaborative effort through YOTC and TPARC;
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Capability acceleration of the High-Performance Computing (HPC)
centers for high-resolution regional and global numerical weather,
climate and environmental science activities;
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Maintaining existing and implementing planned satellite missions that
measure tropical cloud and precipitation systems in order to provide a
long-term capability for process studies, data assimilation and prediction
in collaboration with GCOS.
Forecasting-system improvement at ECMWF
Updated from Simmons & Hollingsworth (2002)
Acknowledgements to A. Simmons
Historical trend
%
Historical re-forecast project
trend using re-analyses
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North America Z500 RMSE for the control experiments
and latest upgrades of the MSC global analysis-forecast system
(January and February 2007)
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Acknowledgements
to S. Laroche
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Data assimilation for coupled models as a prediction and
validation tool for weather and climate research
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Promote research towards the development of a composite data
assimilation system, applying different assimilation steps to different
scales (weather to climate time-scales) and components (atmosphere,
land, ocean, atmospheric composition) of the total Earth system model.
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Promote the need to test climate models in a deterministic prediction
mode, as started within the WCRP SPARC Programme. The seasonal
prediction time frame provides a valuable opportunity to do this.
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Promote the use of advanced data assimilation methodologies for
parameter estimation, both in weather and climate models, through close
collaboration with model developers to interpret assimilation results.
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Promote interdisciplinary research on data assimilation methods
appropriate for the next generation of re-analysis projects aimed at
developing historical records for climate studies.
MJO connection to Canadian surface air
temperature; high-impact weather?
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Lagged winter SAT anomaly in Canada
Significant warm anomaly in central and eastern Canada 1-2 pentads after
MJO phase 3
Utilization of Sub-Seasonal and Seasonal Predictions for Social
and Economic Development
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A need for closer ties between weather and climate research:
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 Understanding how information at the weather/climate interface,
including uncertainty, connects with decision-making
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There is also a great need for much easier access to forecast data by the
user community. These need to be available in special user-oriented
products. How to achieve this service?
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The post-processing techniques that are needed by many users may
require an archive of past forecasts (e.g. for water cycle applications).
Some user applications require an archive of re-forecasts from fixed
models for periods as long as 20 years or more.
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Simplified set of public health- related
decisions and supporting (e.g. Rift
Valley Fever)