Initialization and Numerical Forecasting of a Supercell Storm Observed during STEPS

2005 ◽  
Vol 133 (4) ◽  
pp. 793-813 ◽  
Author(s):  
Juanzhen Sun
Keyword(s):  
Radial Velocity ◽  
Cloud Model ◽  
Precipitation Forecast ◽  
Relative Importance ◽  
Severe Thunderstorm ◽  
Penalty Term ◽  
Supercell Storm ◽  
Wind Analysis ◽  
Storm Evolution ◽  
The Cost

The feasibility of initializing a numerical cloud model with single-Doppler observations and predicting the evolution of thunderstorms has been tested using an observed case of a supercell storm during the Severe Thunderstorm Electrification and Precipitation Study (STEPS). Single-Doppler observations from the Weather Surveillance Radar-1988 Doppler (WSR-88D) at Goodland, Kansas, are assimilated into a cloud-scale numerical model using a four-dimensional variational data assimilation (4DVAR) scheme. A number of assimilation and short-range numerical prediction experiments are conducted. Both the assimilation and prediction results are compared with those of a dual-Doppler synthesis. The prediction results are also verified with reflectivity observations. It is shown that the analysis of the wind field captures the major structure of the storm as revealed by the dual-Doppler synthesis. Thermodynamical and microphysical features retrieved through the dynamical model show consistency with expectations for a deep convective storm. The predicted storm evolution represented by the reflectivity field correlates well with the observations for a 2-h prediction period. The relative importance of the initial fields on the subsequent prediction of the storm evolution is examined by alternately removing the perturbation in each of the initial fields. It is shown that the prediction is most sensitive to the initialization of wind, water vapor, and temperature perturbations. A number of sensitivity experiments for initialization are conducted to show how the initial analysis depends on the application of a cycling procedure, the weights of the smoothness constraint, and the relative importance between the radial velocity and the reflectivity observations. It is found that the application of the cycling procedure improves the analysis and the subsequent forecast. Greater smoothness coefficients of the penalty term in the cost function result in a larger rms difference in the wind analysis, but help spread the information out and improve the forecast slightly. The radial velocity observations play a more important role than the reflectivity in terms of the wind analysis and the subsequent precipitation forecast.

scholarly journals Numerically Simulated Electrification and Lightning of the 29 June 2000 STEPS Supercell Storm

2006 ◽  
Vol 134 (10) ◽  
pp. 2734-2757 ◽  
Author(s):  
Kristin M. Kuhlman ◽  
Conrad L. Ziegler ◽  
Edward R. Mansell ◽  
Donald R. MacGorman ◽  
Jerry M. Straka
Keyword(s):  
Mass Flux ◽  
Cloud Model ◽  
Three Dimensional ◽  
Cloud Water ◽  
Severe Thunderstorm ◽  
Charge Structure ◽  
Flash Rate ◽  
Supercell Storm ◽  
Mapping Array ◽  
Cloud To Ground Lightning

Abstract A three-dimensional dynamic cloud model incorporating airflow dynamics, microphysics, and thunderstorm electrification mechanisms is used to simulate the first 3 h of the 29 June 2000 supercell from the Severe Thunderstorm Electrification and Precipitation Study (STEPS). The 29 June storm produced large flash rates, predominately positive cloud-to-ground lightning, large hail, and an F1 tornado. Four different simulations of the storm are made, each one using a different noninductive (NI) charging parameterization. The charge structure, and thus lightning polarity, of the simulated storm is sensitive to the treatment of cloud water dependence in the different NI charging schemes. The results from the simulations are compared with observations from STEPS, including balloon-borne electric field meter soundings and flash locations from the Lightning Mapping Array. For two of the parameterizations, the observed “inverted” tripolar charge structure is well approximated by the model. The polarity of the ground flashes is opposite that of the lowest charge region of the inverted tripole in both the observed storm and the simulations. Total flash rate is well correlated with graupel volume, updraft volume, and updraft mass flux. However, there is little correlation between total flash rate and maximum updraft speed. Based on the correlations found in both the observed and simulated storm, the total flash rate appears to be most representative of overall storm intensity.

Statistical Evaluation for claims and disputes in construction contracts

2017 ◽  
Vol 5 (2) ◽  
pp. 80-96
Author(s):  
Raid Saleem Abd Ali ◽  
Nooran kanaan Yassin
Keyword(s):  
Construction Projects ◽  
Statistical Evaluation ◽  
Relative Importance ◽  
Minimum Level ◽  
Construction Contracts ◽  
Long Period ◽  
Price Schedule ◽  
Questionnaire Form ◽  
The Subject ◽  
The Cost

This research aims to diagnose and identify the causes of claims and disputes between the contractor and the employer, also review the methods used to resolve disputes in construction contracts. In order to achieve the goal of the research, scientific methodology is followed to collect information and data on the subject of claims and disputes in construction projects in Iraq through personal interviews and questionnaire form. The most important results in this research are: the price schedule contract as a kind of competitive contracts is the most important and guarantee for the completion of minimum level of claims and disputes with relative importance of (84.1), compared with the (cost plus a percentage of the cost contract) as a kind of negotiating contracts is the most relative importance of (79.6), and the turnkey contract as a kind of special contracts is the most relative importance of (74.2). The  contractor and  his agents are one of the most influence sources in occurring claims and disputes in construction contracts with relative importance of (77.4) followed by the contract documents with relative importance of (74.2) and then the employer with relative importance of (73.2). In addition to the long period of litigation and the multiplicity of veto grades are most negative when contractual disputes have resolved by it, and with relative importance of (86), followed by the large number of issues and lack of efficiency and specialty of Judges with relative importance (78.4). Finally, the direct negotiation method (relative importance of 77) is one of the most friendly settlement ways favored by conflicted parties, while the resolution of disputes and claims board (relative importance of 10) occupied the last rank in the friendly settlement ways.

The influence of WSR-88D intra-volume scanning strategies on thunderstorm observations and warnings in the dual-polarization radar era: 2011-2020

2021 ◽  
Author(s):  
Michael M. French
Keyword(s):  
Lead Time ◽  
Elevation Angle ◽  
Large Majority ◽  
Dual Polarization ◽  
Severe Thunderstorm ◽  
Low Level ◽  
Tornado Warnings ◽  
Scanning Strategies ◽  
The Cost ◽  
Organized Convection

Abstract The Weather Surveillance Radar - 1988 Doppler (WSR-88D) network has undergone several improvements in the last decade with the upgrade to dual-polarization capabilities and the ability for forecasters to re-scan the lowest levels of the atmosphere more frequently through the use of Supplemental Adaptive Intra-volume Scanning (SAILS). SAILS reduces the revisit period for scanning the lowest 1 km of the atmosphere but comes at the cost of a longer delay between scans at higher altitudes. This study quantifies how often radar Volume Coverage Patterns (VCPs) and all available SAILS options are used during the issuance of 148,882 severe thunderstorm and 18,263 tornado warnings, and near 10,474 tornado, 58,934 hail, and 127,575 wind reports in the dual-polarization radar era. A large majority of warnings and storm reports were measured with a VCP providing denser low-level sampling coverage. More frequent low-level updates were employed near tornado warnings and reports compared to severe thunderstorm warnings and hail or wind hazards. Warnings issued near a radar providing three extra low-level scans (SAILSx3) were more likely to be verified by a hazard with a positive lead time than warnings with fewer low-level scans. However, extra low-level scans were more frequently used in environments supporting organized convection as shown using watches issued by the Storm Prediction Center. Recently, the number of mid-level radar elevation scans is declining per hour, which can adversely affect the tracking of convective polarimetric signatures, like ZDR columns, which were found above the 0.5° elevation angle in over 99% of cases examined.

Simultaneous source separation using a robust Radon transform

Geophysics ◽  
2014 ◽  
Vol 79 (1) ◽  
pp. V1-V11 ◽  
Author(s):  
Amr Ibrahim ◽  
Mauricio D. Sacchi
Keyword(s):  
Radon Transform ◽  
Real Data ◽  
Radon Transforms ◽  
Accurate Data ◽  
Quadratic Formula ◽  
Penalty Term ◽  
Source Data ◽  
The Cost ◽  
Simultaneous Source ◽  
Incoherent Noise

We adopted the robust Radon transform to eliminate erratic incoherent noise that arises in common receiver gathers when simultaneous source data are acquired. The proposed robust Radon transform was posed as an inverse problem using an [Formula: see text] misfit that is not sensitive to erratic noise. The latter permitted us to design Radon algorithms that are capable of eliminating incoherent noise in common receiver gathers. We also compared nonrobust and robust Radon transforms that are implemented via a quadratic ([Formula: see text]) or a sparse ([Formula: see text]) penalty term in the cost function. The results demonstrated the importance of incorporating a robust misfit functional in the Radon transform to cope with simultaneous source interferences. Synthetic and real data examples proved that the robust Radon transform produces more accurate data estimates than least-squares and sparse Radon transforms.

scholarly journals A Framework for the Improvement of Frugal Design Practices

Designs ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 37
Author(s):  
Ravindra Singh ◽  
Sumedha Seniaray ◽  
Prateek Saxena
Keyword(s):  
Cost Reduction ◽  
Distribution Analysis ◽  
Relative Importance ◽  
Design Practice ◽  
Cumulative Frequency Distribution ◽  
Frugal Innovation ◽  
Importance Index ◽  
The Cost ◽  
Discriminatory Effect

Current frugal design practice is focused on the cost reduction of the product. Despite advancements in the domain of frugal Innovation, it is not systematized to develop products for all sets of users, including marginalized society. Many design researchers and engineers now dedicate time and knowledge to producing practical solutions to enhance the quality of life of the marginal community. The approach currently being adopted restricts the development of products intended for all segments of the users. In this paper, cumulative frequency distribution analysis and the Relative Importance Index is used to identify the essential attributes, which contribute to delivering actual frugal products in terms of functionality, usability, performance, affordability, accessibility, aesthetics, and robustness. The framework is beneficial to eradicate the discriminatory effect of being labeled as “Jugaad” users.

scholarly journals The Influence of Varying Cost Formats on Preferences

2016 ◽  
Vol 37 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Charles Changchuan Jiang ◽  
Liana Fraenkel
Keyword(s):  
Blood Sugar ◽  
Working Hours ◽  
Mechanical Turk ◽  
Treatment Preferences ◽  
Relative Impact ◽  
Relative Importance ◽  
Monthly Income ◽  
Sugar Levels ◽  
The Cost ◽  
The Impact

Background. Numerous studies have found that cost strongly influences patients’ decision making. The objective of this study was to explore the impact of varying cost formats on patients’ preferences. Methods. Mechanical Turk workers completed a choice-based conjoint (CBC) survey. The CBC survey was designed to examine stated preferences for the use of second-line agents to treat diabetes across 5 attributes: route of administration, efficacy, risk of low blood sugar, frequency of checking blood sugar levels, and cost. We developed 7 versions of the CBC survey that were identical except for the cost attribute. We described cost in terms of: Affordability, Monthly Co-pay, Dollar Sign Rating, How Expensive, or How Cheap compared with other medications, Working Hours Equivalent (per mo) and Percent of Monthly Income. The resulting part-worth utilities were used to calculate the relative importance of cost and to estimate treatment preferences for exenatide, a sulfonylurea, and insulin. Results. The relative impact of cost varied significantly across the 7 formats. Cost had the greatest influence on participants’ decisions when framed in terms of Affordability [mean (SD) relative importance, 37.3 (0.9)] and the lowest influence when framed in terms of How Cheap (compared with other drugs) [12.1 (0.9)]. A sulfonylurea was strongly preferred across 4 of the 7 formats. Preference for insulin, the most effective, albeit riskiest, option was low across all cost formats. Conclusions. The format used to describe cost affects how the attribute impacts patients’ preferences. Individuals are most cost-sensitive when cost is framed in terms of affordability and least cost-sensitive when cost is described in terms of how cheap the medication is compared with others.

Allocative inefficiency, X-inefficiency, Bureaucracy and Corruption in Developing Countries

1995 ◽  
Vol 6 (1) ◽  
pp. 55-79
Author(s):  
Geoff Harris
Keyword(s):  
Resource Allocation ◽  
Developing Countries ◽  
Allocative Efficiency ◽  
Decision Makers ◽  
Relative Importance ◽  
Economic Decision ◽  
Factors Of Production ◽  
The Right ◽  
The Cost ◽  
Allocative Inefficiency

Economists have traditionally been concerned with allocative efficiency, that is, with trying to make sure that the various factors of production are allocated so that the cost of any given output is minimized. Thus, they have emphasized the importance of ‘getting the prices right’ so that these reflect the relative scarcities of inputs in the economy and give the right signals, as regards resource allocation, to economic decision-makers. From the mid-1960s, Harvey Leibenstein has drawn attention to what he has termed X-inefficiencies which derive from non-price factors such as protection/shelter of enterprises from competition, inertia on the part of managers and limited effort by workers. This article examines the relative importance of allocative inefficiency, X-inefficiency, bureaucracy and corruption in LDCs. It finds that X-inefficiencies in developing countries are far more important than allocative inefficiencies. In addition, the inefficiencies resulting from each of bureaucracy and corruption, whilst difficult to measure, are at the very least as important as allocative inefficiencies and probably much more important. It also appears that X-inefficiencies are easier and less costly to reduce than allocative inefficiencies.

scholarly journals Analyzing Vortex Winds in Radar-Observed Tornadic Mesocyclones for Nowcast Applications

2015 ◽  
Vol 30 (5) ◽  
pp. 1140-1157 ◽  
Author(s):  
Qin Xu ◽  
Li Wei ◽  
Kang Nai
Keyword(s):  
Vortex Flow ◽  
Computationally Efficient ◽  
Wind Fields ◽  
Background Error ◽  
Error Covariance ◽  
Flow Dependence ◽  
Wind Analysis ◽  
And Performance ◽  
Analysis System ◽  
The Cost

Abstract A computationally efficient method is developed to analyze the vortex wind fields of radar-observed mesocyclones. The method has the following features. (i) The analysis is performed in a nested domain over the mesocyclone area on a selected tilt of radar low-elevation scan. (ii) The background error correlation function is formulated with a desired vortex-flow dependence in the cylindrical coordinates cocentered with the mesocyclone. (iii) The square root of the background error covariance matrix is derived analytically to precondition the cost function and thus enhance the computational efficiency. Using this method, the vortex wind analysis can be performed efficiently either in a stand-alone fashion or as an additional step of targeted finescale analysis in the existing radar wind analysis system developed for nowcast applications. The effectiveness and performance of the method are demonstrated by examples of analyzed wind fields for the tornadic mesocyclones observed by operational Doppler radars in Oklahoma on 24 May 2011 and 20 May 2013.

scholarly journals Quantifying the Cost of Risk in Consumption

2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Mario Tirelli ◽  
Sergio Turner
Keyword(s):  
Panel Data ◽  
Approximation Method ◽  
Additional Benefit ◽  
Relative Importance ◽  
Total Consumption ◽  
Cross Sectional ◽  
Total Cost ◽  
The Cost ◽  
General Preferences ◽  
Consumption Profile

Fixing a risky intertemporal, interagent consumption profile, its total cost is the total willingness to pay for smoothing everyone's consumption. It decomposes into a micro cost that captures the inefficiency in the cross-sectional distribution of total consumption, risky as it is, and a macro cost that captures the additional benefit of eliminating the risk in total consumption, once efficiently redistributed.We consider the risk that a household experiences income mobility and the consequent consumption mobility. U.S. panel data estimates a consumption profile for which we compute the costs. The total cost is 9-18% of total initial consumption for CRRA parameters 1.25-3.5. Of this, 80-90% is the micro cost and only 10-20% is the macro cost. The magnitude of these results, and in particular the relative importance of the micro cost, is in line with previous empirical evidence.Motivated by this evidence we develop the theory of micro cost. Moreover, because the micro cost does not admit a closed form, for general preferences, we lay out an approximation method.

scholarly journals Impact of Assimilating Future Clear-Air Radial Velocity Observations from Phased-Array Radar on a Supercell Thunderstorm Forecast: An Observing System Simulation Experiment Study

2020 ◽  
Vol 148 (9) ◽  
pp. 3825-3845
Author(s):  
Yongjie Huang ◽  
Xuguang Wang ◽  
Christopher Kerr ◽  
Andrew Mahre ◽  
Tian-You Yu ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Phased Array ◽  
System Simulation ◽  
Weather Prediction ◽  
Storm Track ◽  
Vertical Motion ◽  
Precipitation Forecast ◽  
Track Forecast ◽  
Phased Array Radar ◽  
Supercell Thunderstorms

Abstract Phased-array radar (PAR) technology offers the flexibility of sampling the storm and clear-air regions with different update times. As such, the radial velocity from clear-air regions, typically with a lower signal-to-noise ratio, can be measured more accurately. In this work, observing system simulation experiments are conducted to explore the potential value of assimilating clear-air radial velocity observations to improve numerical prediction of supercell thunderstorms. Synthetic PAR observations of a splitting supercell are assimilated at different life cycle stages using an ensemble Kalman filter. Results show that assimilating environmental clear-air radial velocity can reduce wind errors in the near-storm environment and within the precipitation region. Improvements in the forecast are seen at different stages, especially for the forecast after 30 min. After assimilating clear-air radial velocity observations, the probabilities of updraft helicity and precipitation within the corresponding swaths of the truth simulation increase up to 30%–40%. Additional diagnostics suggest that the more accurate track forecast, stronger vertical motion, and better-maintained supercell can be attributed to the better analysis and prediction of the mean environmental winds and linear and nonlinear dynamic forces. Consequently, assimilating clear-air radial velocity produces accurate storm structure (rotating updrafts), updraft size, and storm track, and improves the surface accumulated precipitation forecast. The performance of forecasts with a higher frequency of assimilating clear-air radial velocity does not show systematic improvement. These results highlight the potential of assimilating clear-air radial velocity observations to improve numerical weather prediction forecasts of supercell thunderstorms.

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