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Centre report: Recent changes in the NWP suites of Environment Canada WGNE-27 – Boulder, USA Ayrton Zadra RPN – Environment Canada 17-21 October 2011
Centre report: Recent changes in the NWP suites of Environment Canada
WGNE-27 – Boulder, USA
Ayrton Zadra RPN – Environment Canada 17-21 October 2011
Page 2 – November 7, 2011
Summary of recent changes
OCT 2010 New regional deterministic system (RDPS) APR 2011 New regional deterministic precip analysis (CaPA) JUN 2011 New naming convention for CMC systems JUN 2011 Coupled atmosphere-ocean-ice forecast system for
Gulf of St-Lawrence JUL 2011 Changes in global deterministic system (GDPS) to
improve hurricane forecasts AUG 2011 Upgrade of air-quality portion of Scribe matrices AUG 2011 New global ensemble prediction system (GEPS) AUG 2011 Addition of GPS-RO data SEP 2011 Upgrade to high-res deterministic system (HRDPS) SEP 2011 New regional ensemble prediction system (REPS) OCT 2011 Upgrade to Scribe nowcasting system
DEC 2011? Changes in global global deterministic system (GDPS)
Page 3 – November 7, 2011
Regional Deterministic Prediction System (RDPS)
Oct 2010: New RDPS became operational • limited-area model (red line in figure)
• horizontal resolution: 15km
• 3D-Var assimilation system independent from the global system
• provides pilot data for the air quality forecast model GEM-MACH15
Project lead: L. Fillion
Page 4 – November 7, 2011
Regional Deterministic Precipitation Analysis (RDPA)
Apr 2011: New RDPA based on the Canadian Precipitation Analysis (CaPA) project • Optimal Interpolation (OI)
• Trial field from 15-km RDPS
• New quality control for solid precipitation measurements from automated stations
Project lead: V. Fortin
Ground stations (coop + synoptic stations)
Atmospheric model
Satellite imagery
RADAR
CaPA
Page 5 – November 7, 2011
Gulf of St. Lawrence (GSL) Coupled Atmosphere-Ocean-Ice System
Jun 2011: New fully coupled GSL system • oceanic pseudo-analysis cycle
• superimposed sea ice analysis based on direct insertion of Radarsat analysis
• coupled forecast cycle: - both models (GEM-LAM and OCEAN-ICE) run at the same time
- 00-48 hour weather, sea ice and ocean forecasts
Page 6 – November 7, 2011
Global Deterministic Prediction System (GDPS)
Jul 2011: Upgrades to the GDPS • improvements in the deep convection and thermal roughness length over tropical oceans
• significant reduction in the tropical cyclone (TC) false alarm rate
Project lead: A. Zadra Fig: Comparison of TC false alarms over the Atlantic + East Pacific basins, during the parallel run of Jul-Oct 2010: operational model (blue) and new model (red).
Page 7 – November 7, 2011
Global Ensemble Prediction System (GEPS)
Aug 2011: Upgrades to the GEPS • changes to assimilation system (EnKF) - doubled # of members (96 to 192) - additional satellite data (AMSU-A and GPS-ro) in stratosphere
• changes to forecast system - increased horizontal resolution (100km to 66km) - increased # of levels (28 to 40) - changes/adjustments in physics
• changes to both - staggered vertical levels - model lid raised (10hPa to 2hPa)
Project lead: P. Houtekamer
Continuous Rank Probability Score for GZ500 - winter
Brier Skill Score for precipitation – 5mm threshold - summer
-- OLD -- NEW
-- OLD -- NEW
Page 8 – November 7, 2011
Regional Ensemble Prediction System (REPS)
Sep 2011: New REPS • physics & horizontal grid spacing (0.3° x 0.3°) similar to GDPS (do not use multi-parameterization)
• lid near 10 hPa; use lid nesting technique
- piloting between 10 and 35 hPa - blending between 35 and 100 hPa
• pilot: GEPS (3h freq., lid at 2 hPa)
• initial conditions: global EnKF (same as GEPS)
• lead time: 72 h
• 20 members + 1 control run
• Sources of stochasticity - stochastic perturbations of physical
tendencies - initial conditions (global EnKF) - boundary conditions (GEPS)
Project lead: M. Charron
Page 9 – November 7, 2011
High Resolution Deterministic Prediction System (HRDPS)
Sep 2011: Upgrades to the HRDPS • various upgrades to the model’s dynamics and physics
• increase in the size of the West, East and Maritimes domains
• addition of new domain over the Arctic archipelago
• new verification system exclusive to the HRDPS
Project lead: J. Milbrandt
Fig: 5 LAM grids, Δx = 2.5 km, 58 vertical levels (Charney-Phillips), model lid at 0.1 hPa; 24 h integrations, 1 run per day, nested from GEM Regional (Δx = 15 km) forecast configuration; boundary conditions from 3D-Var regional data assimilation system.
Page 10 – November 7, 2011
Global Deterministic Prediction System (GDPS)
Nov/Dec 2011?: Ongoing upgrades to the GDPS
• New observations - large increase in volume of assimilated obs: - IASI: 62 channels, sensitive to temperature below 150hPa - SSMIS: 7 SSMI-like channels sensitive to humidity and surface wind speed
(over the ocean) - GEORAD: 5 geostationary satellites (previously only 2 GOES satellites), 1
water vapour channel assimilated using RTTOV - AIRS: assimilate upper level channels previously rejected within 30° of both
poles - Reduced horizontal thinning for all satellite radiance observations (250km
150km, except SSMI: 200km 150km) - Humidity from aircraft
• Improved treatment of satellite observations
• New sea-surface temperature analysis Project lead: M. Buehner
Page 11 – November 7, 2011
Planned changes (1-3 years)
2012
• regional deterministic system (RDPS) - increase horizontal resolution (15km => 10km) - from 3DVar to 4DVar - new surface data assimilation system (CaLDAS)
• global deterministic system (GDPS) - increase horizontal resolution (33km => 25km) - higher resolution in 4DVar increments - new surface data assimilation system (CaLDAS) - new sea-ice analysis
Page 12 – November 7, 2011
Planned changes (1-3 years)
2012-2013 • unified 4D assimilation system (En-Var and EnKF)
(i) Dependence of En-Var on EnKF EnKF 4D Benkf(t) En-Var = Variational assimilation with 4D Benkf(t)
(ii) En-Var system - does not require TL/AD of forecast model - better treatment of nonlocal observations (e.g. satellite radiances) - still requires TL/AD of observation operators - assimilate same volume of observations as with 4D-Var and continued increase - flexible use of B matrix (Background Error Covariances)
Page 13 – November 7, 2011
Planned changes (1-3 years)
2012-2013 • unified 4D assimilation system (En-Var and EnKF) (cont.) - two different analysis systems with common scheduler, common modules (e.g. B matrix, Observation Operators) and common data processing tasks (e.g. Background Check, Bias Correction).
- En-Var system to produce deterministic forecast
- EnKF continued development
- same approach for regional analysis system which also needs to meet METAREA objectives
Page 14 – November 7, 2011
Planned changes (coming 1-3 years)
2014+ • new high-resolution deterministic system (HRDPS) - 1 LAM grid, Δx = 2.5 km - 24-36 h integrations, 2-4 runs per day - nested from control member of regional ensemble prediction system (Δx = 10-15 km) - model lid at 30 hPa; upper boundary nesting - high-resolution land data assim. system (250 m) for initial cond. of surface fields
Page 15 – November 7, 2011
Planned changes (1-3 years)
2012-14+ • regional ensemble system (REPS) - increase horizontal resolution (to 10-15km) - forecasts up to day 3 (maybe 4-5)
• global ensemble system (GEPS) - increase horizontal resolution (to ~30km) - for medium- and long-range forecasts
• new high-resolution surface & near-surface system - for weather element forecasting; horizontal resolution ~250m - lead time of several days - initial conditions from ensemble-based Canadian Land Data Assimilation System (CaLDAS)
Page 16 – November 7, 2011
New Integrated Arctic Marine System in support of METAREA
• Development, validation and implementation of marine forecasts • lead times: 1-3 days
• regional high resolution coupled multi-component model (atmosphere, land, snow, ice, ocean, wave) and data assimilation system, to predict: - near surface atmospheric conditions, - sea ice (concentration, pressure, drift, ice edge) - freezing spray, - waves - ocean conditions (temperature and currents)
Fig: Canada is the Preparation and Issuing Service for METAREAS XVII and XVIII and the Danish Meteorological Service will be the Preparation Service for their waters near Greenland for area XVIII.
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