Statistical Quality Control of High-Resolution Winds of Different Radiosonde Types for Climatology Analysis

AbstractQuality control (QC) is among the most important steps in any data processing. These steps are elaborated for high-vertical-resolution radiosonde datasets that were gathered and analyzed to study atmospheric winds. The database is composed of different radiosonde wind-finding systems (WFSs), including radio theodolite, Loran C, and GPS. Inspection of this database, particularly for wind, wind shear, and ascent height increments (dz), showed a nonnegligible amount of outliers in radio theodolite data as compared to the two other WFSs, thus denoting quality differences between the various systems. An effective statistical QC (SQC) is then developed to isolate and eliminate outliers from the more realistic observations. Improving the accuracy of the radio theodolite WFS is critical to the derivation of the vertical motion and the vertical gradients of the horizontal wind—that is, wind shear—mainly because of the direct dependence of these quantities on dz. Based on the climatological distribution of the quality-controlled dz, a new approach is suggested to estimate these wind quantities for radio theodolite data. The approach is validated with the high-quality modern WFSs (Loran C and GPS). Although initially of reduced quality, applying SQC and using the climatological mean dz of 12-s smoothed radio theodolite profiles shows very good improvement in the climatological wind analyses of radio theodolite WFSs. Notably, the climatologies of ascent rate, vertical motion, horizontal wind, and vertical shear now look comparable for the various WFSs. Thus, the SQC processing steps prove essential and may be extended to other variables and measurement systems.

Download Full-text

On the frictional influence of horizontal wind shear on vertical motion

Quarterly Journal of the Royal Meteorological Society ◽

10.1002/qj.49707231403 ◽

1946 ◽

Vol 72 (314) ◽

pp. 284-289

Author(s):

C. H. B. Priestley

Keyword(s):

Wind Shear ◽

Vertical Motion ◽

Horizontal Wind

Download Full-text

Corporate Learning and Quality Control at the Bell System, 1877–1929

The Business History Review ◽

10.1017/s0007680500080193 ◽

2005 ◽

Vol 79 (1) ◽

pp. 39-72 ◽

Cited By ~ 9

Author(s):

Paul J. Miranti

Keyword(s):

Quality Control ◽

Service Learning ◽

The United States ◽

Statistical Quality Control ◽

New Approach ◽

Corporate Learning ◽

Innovative Methods ◽

Gradual Development ◽

Manufacturing Knowledge ◽

Reducing Costs

From 1877 to 1929 the Bell System extended its qualityassurance capabilities, a step that was critical to the company's ability to certify the reliability of its equipment and apparatus and to provide economical service. Learning in this context involved the gradual development of an organizational structure for coordinating and controlling quality-assurance activities at both the staff and line levels and between the corporate elements of the Bell System. Over the course of the initiative, innovative methods of analysis emerged that provided useful new insights into the manufacturing process. The company's adaptation of probability theory, for example, enabled it to launch a comprehensive inspection regime, which became known as “statistical quality control” (SQC). Based on this new approach, Bell succeeded in broadening its manufacturing knowledge, quantifying definitions of quality, reducing costs and risk, thus assuming the more reliable operation of its vast telephone network. Eventually this upgrading of learning led to the formation of a new profession of quality engineering, which found adherents across many industries in the United States and abroad.

Download Full-text

Time series modeling for quality control in clinical chemistry.

Clinical Chemistry ◽

10.1093/clinchem/34.7.1396 ◽

1988 ◽

Vol 34 (7) ◽

pp. 1396-1406 ◽

Cited By ~ 9

Author(s):

L C Alwan ◽

M G Bissell

Keyword(s):

Time Series ◽

Quality Control ◽

Control Charts ◽

Current Practice ◽

Clinical Chemistry ◽

Statistical Quality Control ◽

New Approach ◽

Basic Assumptions ◽

Control Rules ◽

And Performance

Abstract Autocorrelation of clinical chemistry quality-control (Q/C) measurements causes one of the basic assumptions underlying the use of Levey-Jennings control charts to be violated and performance to be degraded. This is the requirement that the observations be statistically independent. We present a proposal for a new approach to statistical quality control that removes this difficulty. We propose to replace the current single control chart of raw Q/C data with two charts: (a) a common cause chart, representing a Box-Jenkins ARIMA time-series model of any underlying persisting nonrandomness in the process, and (b) a special cause chart of the residuals from the above model, which, being free of such persisting nonrandomness, fulfills the criteria for use of the standard Levey-Jennings plotting format and standard control rules. We provide a comparison of the performance of our proposed approach with that of current practice.

Download Full-text

Long-term mean vertical velocity measured by MST radar at Gadanki (13.5° N, 79.2° E)

Annales Geophysicae ◽

10.5194/angeo-27-451-2009 ◽

2009 ◽

Vol 27 (2) ◽

pp. 451-459 ◽

Cited By ~ 4

Author(s):

P. V. Rao ◽

P. Vinay Kumar ◽

M. C. Ajay Kumar ◽

G. Dutta

Keyword(s):

Vertical Velocity ◽

Vertical Motion ◽

Vertical Wind ◽

Vertical Shear ◽

Horizontal Wind ◽

Direct Measurements ◽

Semidiurnal Variation ◽

Vertical Beam ◽

Tropical Station

Abstract. MST radars are capable of measuring vertical motion along a vertically directed beam. We present 8 years (1995–2003) averaged profile of vertical velocity in the troposphere and the lower stratosphere over Gadanki (13.5° N, 79.2° E), a tropical station. A downward mid-tropospheric w is observed with a reversal of sign around 10 km and a further reversal can also be seen at ~17 km. A significant diurnal and semidiurnal variation in vertical wind is observed for all heights with subsidence during the evening hours. Seasonal variability of vertical wind is also found to be quite appreciable. Vertical velocities have been derived using symmetric pairs of off-vertical beams and a comparison has been made with direct vertical beam measurements. Vertical components estimated from E-W and N-S radial velocities do not match and are also found to have discrepancy with direct measurements. Plausible causes of the discrepancy have been investigated with the help of some case studies. Vertical shear in horizontal wind, gradients in horizontal velocities and echo power imbalance may be some of the factors responsible for the observed discrepancy.

Download Full-text

A Horizontal Wind and Wind Confidence Algorithm for Doppler Wind Profilers

Journal of Atmospheric and Oceanic Technology ◽

10.1175/1520-0426-19.3.257 ◽

2002 ◽

Vol 19 (3) ◽

pp. 257-273 ◽

Cited By ~ 8

Author(s):

Robert K. Goodrich ◽

Corrinne S. Morse ◽

Larry B. Cornman ◽

Stephen A. Cohn

Keyword(s):

Quality Control ◽

Wind Shear ◽

Signal To Noise Ratio ◽

Weighted Average ◽

Warning System ◽

Horizontal Wind ◽

Flight Operations ◽

Average Wind ◽

Control Metric ◽

Wind Profilers

Abstract Boundary layer wind profilers are increasingly being used in applications that require high-quality, rapidly updated winds. An example of this type of application is an airport wind hazard warning system. Wind shear can be a hazard to flight operations and is also associated with the production of turbulence. A method for calculating wind and wind shear using a linear wind field assumption is presented. This method, applied to four- or five-beam profilers, allows for the explicit accounting of the measurable shear terms. An error analysis demonstrates why some shears are more readily estimated than others, and the expected magnitudes of the variance for the wind and wind shear estimates are given. A method for computing a quality control index, or confidence, for the calculated wind is also presented. This confidence calculation is based on an assessment of the validity of the assumptions made in the calculations. Confidence values can be used as a quality control metric for the calculated wind and can also be used in generating a confidence-weighted average wind value from the rapid update values. Results are presented that show that errors in the wind estimates are reduced after removing values with low confidence. The wind and confidence methods are implemented in the NCAR Wind and Confidence Algorithm (NWCA), and have been used with the NCAR Improved Moments Algorithm (NIMA) method for calculating moments and associated moment confidence from Doppler spectra. However, NWCA may be used with any moment algorithm that also computes a first moment confidence. For example, a very simple confidence algorithm can be defined in terms of the signal-to-noise ratio.

Download Full-text

Integrating the continuous improvement of measurement systems into the statistical quality control of manufacturing processes: A novel link

CIRP Annals ◽

10.1016/j.cirp.2012.03.017 ◽

2012 ◽

Vol 61 (1) ◽

pp. 507-510 ◽

Cited By ~ 5

Author(s):

María Villeta ◽

Eva María Rubio ◽

José Luis Valencia ◽

Miguel Ángel Sebastián

Keyword(s):

Quality Control ◽

Continuous Improvement ◽

Statistical Quality Control ◽

Manufacturing Processes ◽

Measurement Systems ◽

Statistical Quality

Download Full-text

Doppler radar spectral width broadening due to beamwidth and wind shear

Annales Geophysicae ◽

10.1007/s00585-997-0786-7 ◽

1997 ◽

Vol 15 (6) ◽

pp. 786-796 ◽

Cited By ~ 53

Author(s):

G. D. Nastrom

Keyword(s):

Wind Shear ◽

Vertical Wind Shear ◽

Spectral Width ◽

Analytic Solutions ◽

Vertical Shear ◽

Horizontal Wind ◽

Dimensional Model ◽

Spectral Broadening ◽

Vhf Radar ◽

Beam Broadening

Abstract. The spectral width observed by Doppler radars can be due to several effects including the atmospheric turbulence within the radar sample volume plus effects associated with the background flow and the radar geometry and configuration. This study re-examines simple models for the effects due to finite beamwidth and vertical shear of the horizontal wind. Analytic solutions of 1- and 2-dimensional models are presented. Comparisons of the simple 2-dimensional model with numerical integrations of a 3-dimensional model with a symmetrical Gaussian beam show that the 2-dimensional model is usually adequate. The solution of the 2-dimensional model gives a formula that can be applied easily to large data sets. Analysis of the analytic solutions of the 2-dimensional model for off-vertical beams reveals a term that has not been included in mathematical formulas for spectral broadening in the past. This term arises from the simultaneous effects of the changing geometry due to curvature within a finite beamwidth and the vertical wind shear. The magnitude of this effect can be comparable to that of the well-known effects of beam-broadening and wind shear, and since it can have either algebraic sign, it can significantly reduce (or increase) the expected spectral broadening, although under typical conditions it is smaller than the beam-broadening effect. The predictions of this simple model are found to be consistent with observations from the VHF radar at White Sands Missile Range, NM.

Download Full-text

On the Initial Development of Asymmetric Vertical Motion and Horizontal Relative Flow in a Mature Tropical Cyclone Embedded in Environmental Vertical Shear

Journal of the Atmospheric Sciences ◽

10.1175/jas-d-12-0335.1 ◽

2013 ◽

Vol 70 (11) ◽

pp. 3471-3491 ◽

Cited By ~ 23

Author(s):

Yamei Xu ◽

Yuqing Wang

Keyword(s):

Tropical Cyclone ◽

Dominant Role ◽

Vertical Motion ◽

Vertical Shear ◽

Horizontal Wind ◽

Asymmetric Flow ◽

Initial Development ◽

Budget Analysis ◽

Tangential Wind ◽

Relative Flow

Abstract In this paper, the authors focus on the initial development of asymmetric vertical motion and horizontal relative flow in a mature tropical cyclone (TC) embedded in an environmental vertical shear. The fully compressible, nonhydrostatic TC model was used to perform a series of numerical experiments with a mature TC with different intensities embedded in shear with different magnitudes and different vertical profiles. Results show that the development of both the wavenumber-1 asymmetric vertical motion and horizontal relative flow for a TC embedded in vertical shear is quite sensitive to both the magnitude and the vertical profile of wind shear, as well as the intensity of the TC itself. Diagnostic analysis based on the quasi-balanced potential vorticity inversion indicates that the balanced dynamics can only explain a small portion of the asymmetric vertical motion and relative flow. The unbalanced processes contribute predominantly to the development of the asymmetric flow in the simulations. It is shown that the eyewall of a mature TC plays a role somewhat like a material cylinder embedded in an environmental flow with vertical shear. The interaction between the environmental shear and the eyewall produces vertical gradient of convergence/divergence of horizontal wind around the lateral edge of the eyewall. This forces much stronger asymmetric vertical motion than the balanced processes do and drives significant horizontal relative divergent flow over the storm core, which opposes vertical shear and reduces the vertical tilt of the storm axis. In addition, the budget analysis for the axisymmetric tangential wind demonstrates that the asymmetric flow plays a dominant role in weakening the storm top down.

Download Full-text

Response of Atmospheric Convection to Vertical Wind Shear: Cloud-System-Resolving Simulations with Parameterized Large-Scale Circulation. Part I: Specified Radiative Cooling

Journal of the Atmospheric Sciences ◽

10.1175/jas-d-13-0320.1 ◽

2014 ◽

Vol 71 (8) ◽

pp. 2976-2993 ◽

Cited By ~ 32

Author(s):

Usama Anber ◽

Shuguang Wang ◽

Adam Sobel

Keyword(s):

Wind Shear ◽

Large Scale ◽

Vertical Wind Shear ◽

Surface Fluxes ◽

Vertical Wind ◽

Vertical Shear ◽

Horizontal Wind ◽

Nonmonotonic Dependence ◽

Convective Systems ◽

Mass Fluxes

Abstract It is well known that vertical wind shear can organize deep convective systems and greatly extend their lifetimes. Much less is known about the influence of shear on the bulk properties of tropical convection in statistical equilibrium. To address the latter question, the authors present a series of cloud-resolving simulations on a doubly periodic domain with parameterized large-scale dynamics based on the weak temperature gradient (WTG) approximation. The horizontal-mean horizontal wind is relaxed strongly in these simulations toward a simple unidirectional linear vertical shear profile in the troposphere. The strength and depth of the shear layer are varied as control parameters. Surface enthalpy fluxes are prescribed. The results fall in two distinct regimes. For weak wind shear, time-averaged rainfall decreases with shear and convection remains disorganized. For larger wind shear, rainfall increases with shear, as convection becomes organized into linear mesoscale systems. This nonmonotonic dependence of rainfall on shear is observed when the imposed surface fluxes are moderate. For larger surface fluxes, convection in the unsheared basic state is already strongly organized, but increasing wind shear still leads to increasing rainfall. In addition to surface rainfall, the impacts of shear on the parameterized large-scale vertical velocity, convective mass fluxes, cloud fraction, and momentum transport are also discussed.

Download Full-text