Search Results

You are looking at 171 - 180 of 2,183 items for :

  • Model performance/evaluation x
  • Journal of Atmospheric and Oceanic Technology x
  • Refine by Access: All Content x
Clear All
John T. Snow, Donald E. Lund, Mark D. Conner, Shawn B. Harley, and Catherine B. Pedigo

photograph of the Weathertronics Model 2030 Anemometer and the associated Model 2024 Translator, with centimeterscale in foreground.measuring system parallel those in the standard of theAmerican Society of Testing and Materials (ASTM1985 ) for calibrating rotating anemometers. However,the procedures were modified to recognize that a windmeasuring system was being evaluated rather than justa wind sensor.b. Static calibration The standard specifies a procedure for collecting thenecessary data to

Full access
Ronald D. Leeper, Michael A. Palecki, and Egg Davis

redundantly monitored gauge data and to document the performance of these methods using field data and synthetically generated precipitation events. The outcome of this comparison study not only validates the USCRN QA approach but also provides valuable insight into development and evaluation strategies for precipitation QA systems in general. This is particularly true for QA specialists of other networks considering the adoption of redundant observation systems as this approach to monitoring

Full access
Xuefeng Zhang, Guijun Han, Dong Li, Xinrong Wu, Wei Li, and Peter C. Chu

empirical physical schemes even if the initial field is perfect. With a biased initial field alone, one expects that the parameter optimization can compensate for both the numerical and physical deficiencies of the numerical model and enhance the performance of the model simulation to a certain degree. In this situation, parameters can only converge to their optimal value, instead of the truth values. In the next section, real temperature profiles from OWS Papa will be assimilated into the

Full access
A. Alvarez and B. Mourre

, designs were selected based upon experience and intuition, and their performance was evaluated in terms of the corresponding objective functions. Barth and Wunsch (1990) and Barth (1992) incorporated nonlinear optimization methods (simulated annealing and genetic algorithms, respectively) to search for the best array configuration in different oceanographic sampling problems. Specifically, the former investigated the best static configuration of an array of acoustic tomographic sensors, while the

Full access
Mohammad-Hossein Golbon-Haghighi and Guifu Zhang

algorithm are introduced. In section 3 , the implementation procedures of the algorithm are discussed, and the performance of the algorithm is evaluated using controlled datasets collected by the Norman, Oklahoma (KOUN), polarimetric radar. Conclusions are drawn in section 4 . 2. Discriminant functions A new discriminant function is introduced in this section to develop ground clutter detection algorithms. Controlled training and testing datasets have been used to estimate the PDF of discriminant

Full access
Renzo Bechini and V. Chandrasekar

the optimization procedure on a reduced number of parameters. In this way, although the subset of the remaining parameters may converge to different values with respect to the full model configuration, the summary statistical measures allow for evaluating the relevance to the nowcasting of the individual components of the model. Figure 14 reports the results for the performance of rainwater nowcasting (left panel) and wind direction (right panel). The impact on the wind velocity is not

Full access
Matthew L. Aitken, Michael E. Rhodes, and Julie K. Lundquist

1. Introduction The importance of reliable vertical wind profiles for both resource assessment and evaluation of turbine performance continues to rise with the rapidly escalating use of wind power in both domestic and worldwide energy production. Meteorological towers used to collect wind data, however, are usually constructed no higher than 60 m in the United States for reasons concerning structural stability, cost, and zoning regulations. With hub heights of 80–100 m and rotor diameters of 80

Full access
L. Zedel

the operation of a profiling coherent sonar, but it is important to note that point measurement acoustic Doppler velocimeters (ADVs) operate using the same coherent sampling principle ( Cabrera and Lohrmann 1993 ; Lohrmann et al. 1994 ). The model could therefore be used to evaluate characteristics of that system’s performance as well. Of the results presented here, it is the exploration of averaging effects that is most applicable to ADV operation. For low-correlation coefficients, averaging

Full access
R. Mínguez, B. G. Reguero, A. Luceño, and F. J. Méndez

of wind fields. An additional problem related to wave hindcast databases is the bad performance during hurricanes and typhoons. These inconsistencies are produced because of the difficulty of specifying accurate wind fields and the scarcity of high-quality wave measurements during these events. Thus, to better catch up ocean surface behavior when hurricane and typhoons occur, models with higher spatial and temporal resolution must be used. These models take advantage of (i) the advances made in

Full access
M. Portabella and A. Stoffelen

scatterometer winds are fixed in all datasets and used as reference. The two other wind-observing systems (i.e., buoys and NWP) are presented at varying heights and stability conditions, such that the true and error variances can be evaluated for the different datasets. In this way, the interpretation of the different observing systems and the performance of the SL models are characterized in this section. a. Triple collocation exercise Stoffelen (1998b) shows that when the three observing systems

Full access