Application of multimodel ensemble techniques for real time district level rainfall forecasts in short range time scale over Indian region

2009 ◽  
Vol 106 (1-2) ◽  
pp. 19-35 ◽  
Author(s):  
S. K. Roy Bhowmik ◽  
V. R. Durai
Keyword(s):  
Real Time ◽  
Time Scale ◽  
Short Range ◽  
District Level ◽  
Indian Region ◽  
Multimodel Ensemble ◽  
Ensemble Techniques

scholarly journals A Probabilistic Multimodel Ensemble Approach to Seasonal Prediction

2009 ◽  
Vol 24 (3) ◽  
pp. 812-828 ◽  
Author(s):  
Young-Mi Min ◽  
Vladimir N. Kryjov ◽  
Chung-Kyu Park
Keyword(s):  
Real Time ◽  
Gaussian Approximation ◽  
Seasonal Prediction ◽  
Asia Pacific ◽  
Ensemble Prediction ◽  
Prediction System ◽  
Sampling Errors ◽  
Seasonal Forecasts ◽  
Multimodel Ensemble ◽  
Ensemble Prediction System

Abstract A probabilistic multimodel ensemble prediction system (PMME) has been developed to provide operational seasonal forecasts at the Asia–Pacific Economic Cooperation (APEC) Climate Center (APCC). This system is based on an uncalibrated multimodel ensemble, with model weights inversely proportional to the errors in forecast probability associated with the model sampling errors, and a parametric Gaussian fitting method for the estimate of tercile-based categorical probabilities. It is shown that the suggested method is the most appropriate for use in an operational global prediction system that combines a large number of models, with individual model ensembles essentially differing in size and model weights in the forecast and hindcast datasets being inconsistent. Justification for the use of a Gaussian approximation of the precipitation probability distribution function for global forecasts is also provided. PMME retrospective and real-time forecasts are assessed. For above normal and below normal categories, temperature forecasts outperform climatology for a large part of the globe. Precipitation forecasts are definitely more skillful than random guessing for the extratropics and climatological forecasts for the tropics. The skill of real-time forecasts lies within the range of the interannual variability of the historical forecasts.

Real-Time Anomaly Detection of Short-Time-Scale GWAC Survey Light Curves

2017 ◽  
Author(s):  
Tianzhi Feng ◽  
Zhihui Du ◽  
Yankui Sun ◽  
Jianyan Wei ◽  
Jing Bi ◽  
...  
Keyword(s):  
Anomaly Detection ◽  
Real Time ◽  
Time Scale ◽  
Light Curves ◽  
Short Time Scale ◽  
Short Time

Multirate Integration in Hybrid Electric Vehicle Virtual Proving Grounds

1998 ◽  
Author(s):  
Dario Solis ◽  
Chris Schwarz
Keyword(s):  
Real Time ◽  
Electric Vehicle ◽  
Time Scales ◽  
Electric Vehicles ◽  
Time Scale ◽  
Hybrid Electric Vehicle ◽  
Hybrid Electric Vehicles ◽  
Differential Algebraic Equations ◽  
Vehicle Systems ◽  
Hybrid Electric

Abstract In recent years technology development for the design of electric and hybrid-electric vehicle systems has reached a peak, due to ever increasing restrictions on fuel economy and reduced vehicle emissions. An international race among car manufacturers to bring production hybrid-electric vehicles to market has generated a great deal of interest in the scientific community. The design of these systems requires development of new simulation and optimization tools. In this paper, a description of a real-time numerical environment for Virtual Proving Grounds studies for hybrid-electric vehicles is presented. Within this environment, vehicle models are developed using a recursive multibody dynamics formulation that results in a set of Differential-Algebraic Equations (DAE), and vehicle subsystem models are created using Ordinary Differential Equations (ODE). Based on engineering knowledge of vehicle systems, two time scales are identified. The first time scale, referred to as slow time scale, contains generalized coordinates describing the mechanical vehicle system that includs the chassis, steering rack, and suspension assemblies. The second time scale, referred to as fast time scale, contains the hybrid-electric powertrain components and vehicle tires. Multirate techniques to integrate the combined set of DAE and ODE in two time scales are used to obtain computational gains that will allow solution of the system’s governing equations for state derivatives, and efficient numerical integration in real time.

scholarly journals Adding to Fire Fighter Safety by Including Real-Time Radar Data in Short-Range Forecasts of Thunderstorm-Induced Wind Shifts

Fire ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 55
Author(s):  
Gary L. Achtemeier ◽  
Scott L. Goodrick
Keyword(s):  
Real Time ◽  
Short Range ◽  
Prediction Models ◽  
Weather Prediction ◽  
Radar Data ◽  
Mitigation Strategies ◽  
Density Currents ◽  
Gust Fronts ◽  
Gust Front ◽  
Range Forecasts

Abrupt changes in wind direction and speed caused by thunderstorm-generated gust fronts can, within a few seconds, transform slow-spreading low-intensity flanking fires into high-intensity head fires. Flame heights and spread rates can more than double. Fire mitigation strategies are challenged and the safety of fire crews is put at risk. We propose a class of numerical weather prediction models that incorporate real-time radar data and which can provide fire response units with images of accurate very short-range forecasts of gust front locations and intensities. Real-time weather radar data are coupled with a wind model that simulates density currents over complex terrain. Then two convective systems from formation and merger to gust front arrival at the location of a wildfire at Yarnell, Arizona, in 2013 are simulated. We present images of maps showing the progress of the gust fronts toward the fire. Such images can be transmitted to fire crews to assist decision-making. We conclude, therefore, that very short-range gust front prediction models that incorporate real-time radar data show promise as a means of predicting the critical weather information on gust front propagation for fire operations, and that such tools warrant further study.

A Calibrated Combination of Probabilistic Precipitation Forecasts to Achieve a Seamless Transition from Nowcasting to Very Short-Range Forecasting

2020 ◽  
Vol 35 (3) ◽  
pp. 773-791
Author(s):  
Peter Schaumann ◽  
Mathieu de Langlard ◽  
Reinhold Hess ◽  
Paul James ◽  
Volker Schmidt
Keyword(s):  
Real Time ◽  
Short Range ◽  
Lead Times ◽  
New Model ◽  
Combination Model ◽  
Logit Transformation ◽  
Interaction Terms ◽  
Probabilistic Forecasts ◽  
Seamless Transition ◽  
The Ideal

Abstract In this paper, a new model for the combination of two or more probabilistic forecasts is presented. The proposed combination model is based on a logit transformation of the underlying initial forecasts involving interaction terms. The combination aims at approximating the ideal calibration of the forecasts, which is shown to be calibrated, and to maximize the sharpness. The proposed combination model is applied to two precipitation forecasts, Ensemble-MOS and RadVOR, which were developed by Deutscher Wetterdienst. The proposed combination model shows significant improvements in various forecast scores for all considered lead times compared to both initial forecasts. In particular, the proposed combination model is calibrated, even if both initial forecasts are not calibrated. It is demonstrated that the method enables a seamless transition between both initial forecasts across several lead times to be created. Moreover, the method has been designed in such a way that it allows for fast updates in nearly real time.

Method and device for real-time scale measurements: surface optical properties of small biological objects

1994 ◽  
Author(s):  
Alexander S. Pekarik ◽  
Stanislav G. Rozuvan ◽  
Eugene A. Tikhonov
Keyword(s):  
Optical Properties ◽  
Real Time ◽  
Time Scale ◽  
Biological Objects ◽  
Real Time Scale ◽  
Surface Optical
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