Theme 2: Modeling, Data Assimilationand Advanced Computing

Theme 2: Modeling, Data Assimilationand Advanced Computing

Regional and Global Data Assimilation

Stephen S. Weygandt

Data Assimilation at ESRL Data Assimilation at ESRL

ESRL Physical Sciences Review 9-12 March 2009

Longstanding expertise in the development and application of innovative regional and global data assimilation techniques

Rapid Update Cycle & Rapid Refresh

Local Analysis and Prediction System

Space-Time Mesoscale Analysis System

Global ensemble Kalman Filter assimilation

Rapid Update CycleRapid Update Cycle

ESRL Physical Sciences Review 9-12 March 2009

Each hour, blend observations and background to get the freshest forecast

1-hrfcst

1-hrfcst

1-hrfcst

11 12 13Time (UTC)

AnalysisFields

3DVAR

Obs

3DVAR

Obs

Back-groundFields

Data types usedRawinsondes

Wind Profilers (405, 915 MHz)RASS virtual temperatures

VAD winds (WSR-88D radars)Aircraft (ACARS, TAMDAR)

Surface (METAR), Buoy, MesonetPrecipitable water (GPS, GOES, SSM/I)

GOES cloud-top pressure/tempGOES cloud-drift windsRadar reflectivity, lightningShip reports/dropsondes

Rapid RefreshRapid Refresh

ESRL Physical Sciences Review 9-12 March 2009

Expand high frequency updating concept to full North American domain

Rapid Refresh Use Gridpoint Statistical Interpolation (GSI) and WRF-ARW model

Hourly updating including use of novel observations (satellite clouds & moisture, lighting, air quality data)

RUC

High Resolution Rapid RefreshHigh Resolution Rapid Refresh

ESRL Physical Sciences Review 9-12 March 2009

A convection resolving nest with radar assimilation to initialize thunderstorms

Rapid Refresh

HRRR

Use Gridpoint Statistical Interpolation (GSI) and WRF-ARW model

Detailed forecasts from 3-km HRRR for NextGen, Warn on Forecast, and other applications

Local Analysis and Prediction SystemLocal Analysis and Prediction System

ESRL Physical Sciences Review 9-12 March 2009

Highly portable analysis / forecast system with unique assimilation features

Detailed cloud analysis fuses multiple observation types

“Hot start” to initialize active precipitation areas

AWIPS data assimilation application for NWS offices

Applications for military, fire weather, hydrology

Space-Time Mesoscale Analysis SystemSpace-Time Mesoscale Analysis System

ESRL Physical Sciences Review 9-12 March 2009

Sequential variational multi-grid analysisfor surface and 3D applications

Utilizes LAPS data processing

Iterative solution obtains progressively more detail

Real-time surface application using mesonet data every 15 minutes for frontal detection

Applications for hurricane & severe weather analysis STMAS analysis of hurricane Katrina

950 mb wind speed and barbs

Global Ensemble Kalman FilterGlobal Ensemble Kalman Filter

ESRL Physical Sciences Review 9-12 March 2009

Placeholder – havematerial from Jeff Whitaker

Data Assimilation at ESRL Data Assimilation at ESRL

ESRL Physical Sciences Review 9-12 March 2009

Success in assimilation of remotely sensed observations (radar, satellite, lightning) and development of advanced techniques

Cloud and hydrometeor analysis

Initializing convective storms

Use of surface observations

Flow-dependent error covariances

Cloud and Hydrometeor AnalysisCloud and Hydrometeor Analysis

ESRL Physical Sciences Review 9-12 March 2009

observations

data fusion

adjustment to

background

Incremental adjustment based on information from multiple observation types

Initializing Convective StormsInitializing Convective Storms

ESRL Physical Sciences Review

Hi-Res Rapid Refresh 6-h forecasts

NSSL radarverification

No radarassimilation

RUC radarassimilation

06 UTC 16 Aug. 2007

Digital Filter-based reflectivity assimilationgreatly improves thunderstorm prediction

Use of surface ObservationsUse of surface Observations

ESRL Physical Sciences Review 9-12 March 2009

Placeholder – havematerial from AMB/FAB

Flow-Dependent Error CovariancesFlow-Dependent Error Covariances

ESRL Physical Sciences Review 9-12 March 2009

Placeholder – havematerial from Jeff Whitaker

Data Assimilation at ESRL Data Assimilation at ESRL

ESRL Physical Sciences Review 9-12 March 2009

Continued development in collaboration with NCEP, JCSDA, NCAR, AFWA, CAPS, others on:

Advanced techniques (EnKF, hybrid approaches)Specific observing systems, phenomena (radar, satellite, surface – thunderstorms, clouds, hurricanes)

Foci: overall accuracy, specific applications (NextGen)

Data Assimilation at ESRL Data Assimilation at ESRL

ESRL Physical Sciences Review 9-12 March 2009

DA critical for successful prediction…

Continued development in collaboration with NCEP, JCSDA, NCAR, AFWA, CAPS, others on:

Advanced techniques (EnKF, hybrid approaches)Specific observing systems, phenomena (radar, satellite, surface – thunderstorms, clouds, hurricanes)

Foci: overall accuracy, specific applications (NextGen)

Data Assimilation at ESRL Data Assimilation at ESRL

ESRL Physical Sciences Review 9-12 March 2009

Continued development in collaboration with NCEP, JCSDA, NCAR, AFWA, CAPS, others on:

Advanced techniques (EnKF, hybrid approaches)Specific observing systems, phenomena (radar, satellite, surface – thunderstorms, clouds, hurricanes)

Foci: overall accuracy, specific applications (NextGen)

DA critical for successful prediction…… from global to local scales