Response of a Two-Dimensional Dual-Doppler Radar Wind Synthesis

Given, Terence; Ray, Peter S.

doi:10.1175/1520-0426(1994)011<0239:roatdd>2.0.co;2

Cited by 12 publications

(8 citation statements)

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“…Studies of traditional dual-Doppler analysis methods have shown that wind retrieval errors can be substantially reduced through the judicious selection of the interpolation scheme used to map the Doppler velocity observations to the Cartesian analysis grid (Given and Ray 1994;Trapp and Doswell 2000;Majcen et al 2008). Determining the optimal interpolation procedure for a particular problem, however, can be very challenging.…”

Section: B Sensitivity To Interpolation Proceduresmentioning

confidence: 99%

“…Matejka and Bartels (1998) examined the impact of random, bias, and trend errors in the 2D divergence estimates on the analyzed vertical wind for a number of retrieval methods. Given and Ray (1994), Trapp and Doswell (2000), and Majcen et al (2008) explored the sensitivity of Cartesian analyses to the procedure used to interpolate observations to the analysis grid. Clark et al [1980 (CHM80)] performed multiple-Doppler analyses of pseudo-observations of a numerically simulated severe multicellular storm and examined the impacts of random observational errors, temporal errors due to advection and evolution of the wind field, and, in the dual-Doppler case, unfavorable cross-beam angles.…”

Section: Introductionmentioning

confidence: 99%

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Assessing Errors in Variational Dual-Doppler Wind Syntheses of Supercell Thunderstorms Observed by Storm-Scale Mobile Radars

Potvin

Wicker

Shapiro

2012

Journal of Atmospheric and Oceanic Technology

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Dual-Doppler wind retrieval is an invaluable tool in the study of convective storms. However, the nature of the errors in the retrieved three-dimensional wind estimates and subsequent dynamical analyses is not precisely known, making it difficult to assign confidence to inferred storm behavior. Using an Observing System Simulation Experiment (OSSE) framework, this study characterizes these errors for a supercell thunderstorm observed at close range by two Doppler radars. Synthetic radar observations generated from a high-resolution numerical supercell simulation are input to a three-dimensional variational data assimilation (3DVAR) dualDoppler wind retrieval technique. The sensitivity of the analyzed kinematics and dynamics to the dualDoppler retrieval settings, hydrometeor fall speed parameterization errors, and radar cross-beam angle and scanning strategy is examined.Imposing the commonly adopted assumptions of spatially constant storm motion and intrinsically steady flow produces large errors at higher altitudes. On the other hand, reasonably accurate analyses are obtained at lower and middle levels, even when the majority of the storm lies outside the 308 dual-Doppler lobe. Lowlevel parcel trajectories initiated around the main updraft and rear-flank downdraft are generally qualitatively accurate, as are time series of circulation computed around material circuits. Omitting upper-level radar observations to reduce volume scan times does not substantially degrade the lower-and middle-level analyses, which implies that shallower scanning strategies should enable an improved retrieval of supercell dynamics. The results suggest that inferences about supercell behavior based on qualitative features in 3DVAR dualDoppler and subsequent dynamical retrievals may generally be reliable.

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Section: B Sensitivity To Interpolation Proceduresmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Assessing Errors in Variational Dual-Doppler Wind Syntheses of Supercell Thunderstorms Observed by Storm-Scale Mobile Radars

Potvin

Wicker

Shapiro

2012

Journal of Atmospheric and Oceanic Technology

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“…Another error source that we did not consider in this study is the hydrometeor fall speed estimate, which is generally estimated from radar reflectivity. The sophisticated attenuation correction techniques in particular for shorter wavelength radars (e.g., Kim et al, 2008;Gu et al, 2011) and best estimates of hydrometeor fall speeds (Giangrande et al, 2013) are required to reduce the wind retrieval uncertainties. In brief, the retrieval of the high-quality vertical velocities in the upper part of convective clouds is very challenging, while the multi-Doppler-radar vertical velocity retrievals have been conventionally used to evaluate the CRM simulated dynamical fields.…”

Section: Discussionmentioning

confidence: 99%

Investigation of observational error sources in multi-Doppler-radar three-dimensional variational vertical air motion retrievals

et al. 2019

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Abstract. Multi-Doppler-radar network observations have been used in different configurations over the last several decades to conduct three-dimensional wind retrievals in mesoscale convective systems. Here, the impacts of the selected radar volume coverage pattern (VCP), the sampling time for the VCP, the number of radars used, and the added value of advection correction on the retrieval of the vertical air motion in the upper part of convective clouds are examined using the Weather Research and Forecasting (WRF) model simulation, the Cloud Resolving Model Radar SIMulator (CR-SIM), and a three-dimensional variational multi-Doppler-radar retrieval technique. Comparisons between the model truth (i.e., WRF kinematic fields) and updraft properties (updraft fraction, updraft magnitude, and mass flux) retrieved from the CR-SIM-generated multi-Doppler-radar field are used to investigate these impacts. The findings are that (1) the VCP elevation strategy and sampling time have a significant effect on the retrieved updraft properties above 6 km in altitude; (2) 2 min or shorter VCPs have small impacts on the retrievals, and the errors are comparable to retrievals using a snapshot cloud field; (3) increasing the density of elevation angles in the VCP appears to be more effective to reduce the uncertainty than an addition of data from one more radar, if the VCP is performed in 2 min; and (4) the use of dense elevation angles combined with an advection correction applied to the 2 min VCPs can effectively improve the updraft retrievals, but for longer VCP sampling periods (5 min) the value of advection correction is challenging. This study highlights several limiting factors in the retrieval of upper-level vertical velocity from multi-Doppler-radar networks and suggests that the use of rapid-scan radars can substantially improve the quality of wind retrievals if conducted in a limited spatial domain.

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“…The primarily statistical techniques, which are often termed objective analysis, include ad hoc methods such as Cressman (1959) successive correction (see Given and Ray (1994) for an application; see Trapp and Doswell (2000) and Askelson et al (2000) for discussion of the use of this technique in the analysis of radar data), to optimal interpolation techniques (Gandin, 1963;Thiébaux and Pedder, 1987;see Sokolov and Rintoul (1999) for a recent inter-comparison of techniques). In the latter, care is often taken to model the spatial correlation structure of forecast errors so as to maintain the dynamical balance between forecast parameters, such as geopotential and winds (e.g.…”

Section: Weather Forecastingmentioning

confidence: 99%

On the role of statistics in climate research

Zwiers¹,

Storch²

2004

Intl Journal of Climatology

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We review the role of statistical analysis in the climate sciences. Special emphasis is given to attempts to construct dynamical knowledge from limited observational evidence, and to the ongoing task of drawing detailed and reliable information on the state, and change, of climate that is needed, for example, for short-term and seasonal forecasting. We conclude with recommendations of how to improve the practice of statistical analysis in the climate sciences by drawing more efficiently on relevant developments in statistical mathematics.

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Response of a Two-Dimensional Dual-Doppler Radar Wind Synthesis

Cited by 12 publications

References 0 publications

Assessing Errors in Variational Dual-Doppler Wind Syntheses of Supercell Thunderstorms Observed by Storm-Scale Mobile Radars

Assessing Errors in Variational Dual-Doppler Wind Syntheses of Supercell Thunderstorms Observed by Storm-Scale Mobile Radars

Investigation of observational error sources in multi-Doppler-radar three-dimensional variational vertical air motion retrievals

On the role of statistics in climate research

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