LWG Meeting, Bar Harbor, 06/01/2010 Progress in the Joint OSSE System Lars Peter Riishojgaard and Michiko Masutani JCSDA

LWG Meeting, Bar Harbor, 06/01/2010

Progress in the Joint OSSE System

Lars Peter Riishojgaard and Michiko Masutani

JCSDA

NCEP: Michiko Masutani, Jack Woollen, Yucheng Song, Steve LordECMWF: Erik AnderssonKNMI: Ad Stoffelen, Gert-Jan MarseilleJCSDA: Lars Peter Riishojgaard, Lidia Cucurull, Zaizhong Ma NESDIS: Fuzhong Weng, Tong Zhu, Haibing Sun, SWA: Dave Emmitt, Sid Wood, Steve GrecoNASA/GFSC: Ron Errico, Runhua Yang, Will McCarty, Emily Liu, Michele

Rienecker, Ron GelaroNOAA/ESRL:Yuanfu Xie, Nikki Prive, Steve Weygandt

Joint OSSE Team


NOAA OSSE Testbed initiative (USWRP Executive Committee): Bob Atlas, Steve Koch, …


Role of a National OSSE Capability

• Impact assessment for future missions– Decadal Survey and other science and/or technology

demonstration missions (NASA)– Future operational systems (NOAA)

• Objective way of establishing scientifically sound and technically realistic user requirements for observing systems

• Tool for assessing performance impact of engineering decisions made throughout the development phases of a space program or system

• Preparation/early learning pre-launch tool for assimilation users of data from new sensors


Main OSSE components• Data assimilation system(s)

– NCEP/EMC GFS– NASA/GMAO GEOS-5– NCAR WRF-VAR

• Nature run– ECMWF– Plans for embedded WRF Regional NR

• Simulated observations, including calibrated errors– Reference observations– Perturbation (“candidate”) observations

• Diagnostics capability– “Classical” OSE skill metrics– Adjoint sensitivity studies


ECMWF Nature Run (Erik Andersson)

• Based on recommendations/requirements from JCSDA, NCEP, GMAO, GLA, SIVO, SWA, NESDIS, ESRL

• “Low Resolution” Nature Run – Free-running T511 L91 w. 3-hourly dumps– May 12 2005 through June 1 2006

• (Two “High Resolution” periods of 35 days each– Hurricane season: Starting at 12z September 27,2005,

– Convective precipitation over CONUS: starting at 12Z April 10, 2006 • T799 L91 levecondition ls, one-hourly dump)

• High resolution period abandoned due to poor validation results


Nature Run validation

• Purpose is to ensure that pertinent aspects of meteorology are represented adequately in NR

• Contributions from Emmitt, Errico, Masutani, Prive, Reale, Terry, Tompkins and many others

• Clouds• Precipitation• Extratropical cyclones (tracks, cyclogenesis, cyclolosis)• Tropical cyclones (tracks, intensity)• Mean wind fields• ….


Simulation of observations (I), conventional • Conventional observations: “anything other than satellite radiances”• Conceptually simple: Resample NR at observation locations and add

error

• Problem: For many observation types the locations depend on the atmospheric state:– Radiosondes (drift)– Satellite winds (tracking targets)– Aircraft obs (flight routing)– Ocean surface winds (thresholds and precip)

• This is NOT accounted for currently: Actual historical obs locations for 2005 are used– SWA working on more sophisticated approach to scatterometer

winds and satellite AMVs• Two approaches so far:

– J. Woollen (NCEP), R. Errico (GMAO)

Observation simulation (II): Radiances

• Satellite radiances dominate both in terms of numbers and of impact• Conceptually: Forward radiative transfer applied to NR input profiles

• Problem areas:– Treatment of clouds has substantial impact on availability and

quality of observations, and on subsequent QC, thinning and ultimately assimilation results

– Desire to avoid “identical twin” Radiative Transfer Models; conceptually one should be use one RTM for simulation and a different RTM for assimilation

– NOT yet implemented in Joint OSSE• Two different approaches:

– H. Sun (NESDIS), R. Errico (GMAO)


Radiance simulation steps (NESDIS/NCEP)

• Template data (in initial version, footprints used for operational data assimilation in the real year 2005 were used)

• DBL91 (Nature Run data at footprints to be simulated)• 91 level 3-D data (12 Variables)• 2-D data (71 Variables)• Climatological data• All information to simulate Radiances

• Simulated radiance data saved in ASCII or unpacked format.

• Radiance data to packed to WMO BUFR format, using information from template data.


Version 1

Version 2

Latest version

REAL OSSE

REAL OSSE

Calibration for Joint OSSEs at NASA/GMAO

Version 1

Calibration using adjoint technique

•Overall impact of simulated data seems realistic•Tuning parameter for cloud clearing•Surface emissivity•Improved simulation of AMVs

(Early results; courtesy of Ron Errico)



Current status• Joint OSSE collaboration continues to show progress

– Extensive validation effort completed successfully– Calibration experiments performed by GMAO, NCEP and ESRL– Reference observing system simulation complete for initial

experimental period (July-August 2005)– Wind Lidar project entering year 3

• Ready for initial impact experiments (Michiko’s talk next)• Preliminary simulated lidar winds available from SWA• New post-doc on board (Zaizhong Ma)

• Issues:– The effort remains only partially funded– Coordination– Relationship with NOAA’s OSSE testbed initiative still needs to be

clarified

Documents

LWG Meeting, Bar Harbor, 06/01/2010 Progress in the Joint OSSE System Lars Peter Riishojgaard and Michiko Masutani JCSDA