Issues in targeted observing

This paper summarizes successes and limitations of targeted observing field programmes starting from the Fronts and Atlantic Storm-Track Experiment in 1997 through recent programmes targeting winter storms and tropical cyclones. These field programmes have produced average reductions in short-range forecast errors of about 10 per cent over regional verification areas, and maximum forecast error reductions as large as 50 per cent in certain cases. The majority of targeting cases investigated so far involve sets of dropsondes and other observation data that provide partial coverage of target areas. The primary scientific challenges for targeting include the refinement of objective methods that can identify optimal times and locations for targeted observations, as well as identify the specific types of satellite and in situ measurements that are required for the improvement of numerical weather forecasts. The most advanced targeting procedures, at present, include: the ensemble transform Kalman Filter, Hessian singular vectors, and observation-space targeting using the adjoint of a variational data assimilation procedure. Targeted observing remains an active research topic in numerical weather prediction, with plans for continued refinement of objective targeting procedures, and field tests of new satellite and in situ observing systems. Copyright © 2005 Royal Meteorological Society

[1]  Thierry Bergot,et al.  Adaptive observations during FASTEX: A systematic survey of upstream flights , 1999 .

[2]  Stephen J. Lord,et al.  The impact of Omega dropwindsondes on operational hurricane track forecast models , 1996 .

[3]  Jon Talbot,et al.  ADAPTIVE OBSERVATIONS AT NCEP: PAST, PRESENT, AND FUTURE , 2002 .

[4]  Craig H. Bishop,et al.  Adaptive sampling with the ensemble transform Kalman filter , 2001 .

[5]  Roger Daley,et al.  Observation and background adjoint sensitivity in the adaptive observation‐targeting problem , 2007 .

[6]  Steven J. Nieman,et al.  Upper-Tropospheric Winds Derived from Geostationary Satellite Water Vapor Observations , 1997 .

[7]  C. Reynolds,et al.  Nonlinear growth of singular‐vector‐based perturbations , 2003 .

[8]  Jing-Shan Hong,et al.  Dropwindsonde Observations for Typhoon Surveillance near the Taiwan Region (DOTSTAR): An Overview , 2005 .

[9]  Roberto Buizza,et al.  The Influence of Physical Processes on Extratropical Singular Vectors , 2004 .

[10]  Istvan Szunyogh,et al.  The North Pacific Experiment (NORPEX-98): Targeted Observations for Improved North American Weather Forecasts , 1999 .

[11]  The Impact of Dropwindsonde Data on GFDL Hurricane Model Forecasts Using Global Analyses , 1997 .

[12]  Chris Snyder,et al.  Summary of an Informal Workshop on Adaptive Observations and FASTEX , 1996 .

[13]  James L. Franklin,et al.  Impact on Hurricane Track and Intensity Forecasts of GPS Dropwindsonde Observations from the First-Season Flights of the NOAA Gulfstream-IV Jet Aircraft. , 1999 .

[14]  T. Palmer,et al.  Singular Vectors, Metrics, and Adaptive Observations. , 1998 .

[15]  Philippe Courtier,et al.  Sensitivity of forecast errors to initial conditions , 1996 .

[16]  Thierry Bergot,et al.  A study on the optimization of the deployment of targeted observations using adjoint‐based methods , 2002 .

[17]  Ronald Gelaro,et al.  Singular Vector Calculations with an Analysis Error Variance Metric , 2002 .

[18]  Ronald Gelaro,et al.  Targeted observations in FASTEX: Adjoint‐based targeting procedures and data impact experiments in IOP17 and IOP18 , 1999 .

[19]  Florence Rabier,et al.  Cloud characteristics and channel selection for IASI radiances in meteorologically sensitive areas , 2004 .

[20]  Istvan Szunyogh,et al.  Can an ensemble transform Kalman filter predict the reduction in forecast-error variance produced by targeted observations? , 2001 .

[21]  T. Bergot,et al.  Sensitivity to observations applied to FASTEX cases , 2001 .

[22]  A. P. McNally,et al.  A note on the occurrence of cloud in meteorologically sensitive areas and the implications for advanced infrared sounders , 2002 .

[23]  Z. Pu,et al.  Targeting observations with the quasi‐inverse linear and adjoint NCEP global models: Performance during FASTEX , 1999 .

[24]  J. Thepaut,et al.  Assimilation and Modeling of the Atmospheric Hydrological Cycle in the ECMWF Forecasting System , 2005 .

[25]  Chris Snyder,et al.  Overview of the field phase of the fronts and Atlantic Storm‐Track EXperiment (FASTEX) project , 1999 .

[26]  Sunil Movva,et al.  Earth Science Markup Language: A Solution to Address Data Format Heterogeneity Problems in Atmospheric Sciences , 2005 .

[27]  M. Leutbecher.  A Reduced Rank Estimate of Forecast Error Variance Changes due to Intermittent Modifications of the Observing Network. , 2003 .

[28]  Roberto Buizza,et al.  Forecast skill of the ECMWF model using targeted observations during FASTEX , 1999 .

[29]  Craig H. Bishop,et al.  A Comparison of Adaptive Observing Guidance for Atlantic Tropical Cyclones , 2006 .

[30]  Florence Rabier,et al.  Impact study of the 2003 North Atlantic THORPEX Regional Campaign , 2006 .

[31]  Ronald Gelaro,et al.  Initial Condition Sensitivity and Error Growth in Forecasts of the 25 January 2000 East Coast Snowstorm , 2002 .

[32]  Sim D. Aberson,et al.  Targeted Observations to Improve Operational Tropical Cyclone Track Forecast Guidance , 2003 .

[33]  R. Gelaro,et al.  Estimation of key analysis errors using the adjoint technique , 1998 .

[34]  C. Velden,et al.  Recent Innovations in Deriving Tropospheric Winds from Meteorological Satellites , 2005 .

[35]  A. Joly,et al.  Adjoint sensitivity of the forecast to TOVS observations , 2002 .

[36]  Chris Snyder,et al.  Ensemble‐based targeting experiments during FASTEX: The effect of dropsonde data from the lear jet , 1999 .

[37]  Craig H. Bishop,et al.  A comparison of ensemble‐transform Kalman‐filter targeting guidance with ECMWF and NRL total‐energy singular‐vector guidance , 2002 .

[38]  Rolf H. Langland,et al.  Adjoint-Based Targeting of Observations for Fastex Cyclones, , 1996 .

[39]  Roberto Buizza,et al.  Forecast Skill of Targeted Observations: A Singular-Vector-Based Diagnostic , 2003 .

[40]  Ronald Gelaro,et al.  A Predictability Study Using Geostationary Satellite Wind Observations during NORPEX , 2000 .

[41]  B. Hoskins,et al.  Moist singular vectors and the predictability of some high impact European cyclones , 2005 .

[42]  Roberto Buizza,et al.  Sensitivity Analysis of Forecast Errors and the Construction of Optimal Perturbations Using Singular Vectors , 1998 .

[43]  Craig H. Bishop,et al.  Ensemble Transformation and Adaptive Observations , 1999 .

[44]  Florence Rabier,et al.  Channel selection methods for Infrared Atmospheric Sounding Interferometer radiances , 2002 .

[45]  Erik Andersson,et al.  Influence‐matrix diagnostic of a data assimilation system , 2004 .

[46]  R. Tuleya,et al.  A Numerical Study on the Effects of Environmental Flow on Tropical Storm Genesis , 1981 .

[47]  Thierry Bergot.  Influence of the assimilation scheme on the efficiency of adaptive observations , 2001 .

[48]  Rebecca E. Morss,et al.  Influence of added observations on analysis and forecast errors: Results from idealized systems , 2002 .

[49]  Tim N. Palmer,et al.  Potential improvement to forecasts of two severe storms using targeted observations , 2002 .

[50]  Craig H. Bishop,et al.  Adaptive sampling with the ensemble transform Kalman filter , 2001 .

[51]  Roberto Buizza,et al.  Targeting Observations Using Singular Vectors , 1999 .

[52]  Rolf H. Langland,et al.  As assessment of the singular‐vector approach to targeted observing using the FASTEX dataset , 1999 .

[53]  Jean-Noël Thépaut,et al.  Combined use of sensitivity information and observations to improve meteorological forecasts: A feasibility study applied to the 'Christmas storm' case , 2000 .

[54]  Rolf H. Langland,et al.  Observation Impact during the North Atlantic TReC—2003 , 2005 .

[55]  Istvan Szunyogh,et al.  The Effect of Targeted Dropsonde Observations during the 1999 Winter Storm Reconnaissance Program , 2000 .

[56]  Istvan Szunyogh,et al.  Propagation of the effect of targeted observations: The 2000 Winter Storm Reconnaissance program , 2002 .