scholarly journals Evaluation of Rainfall Forecasts by Three Mesoscale Models during the Mei-Yu Season of 2008 in Taiwan. Part III: Application of an Object-Oriented Verification Method

Atmosphere ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 705
Author(s):  
Chung-Chieh Wang ◽  
Sahana Paul ◽  
Dong-In Lee
Keyword(s):  
Object Oriented ◽  
Tropical Rainfall Measuring Mission ◽  
Weather Research And Forecasting ◽  
Total Rainfall ◽  
Mesoscale Models ◽  
Subjective Analysis ◽  
Verification Method ◽  
Rain Gauges ◽  
Object Based ◽  
Central Weather Bureau

In this study, the performances of Mei-yu (May–June) quantitative precipitation forecasts (QPFs) in Taiwan by three mesoscale models: the Cloud-Resolving Storm Simulator (CReSS), the Central Weather Bureau (CWB) Weather Research and Forecasting (WRF), and the CWB Non-hydrostatic Forecast System (NFS) are explored and compared using an newly-developed object-oriented verification method, with particular focus on the various properties or attributes of rainfall objects identified. Against a merged dataset from ~400 rain gauges in Taiwan and the Tropical Rainfall Measuring Mission (TRMM) data in the 2008 season, the object-based analysis is carried out to complement the subjective analysis in a parallel study. The Mei-yu QPF skill is seen to vary with different aspects of rainfall objects among the three models. The CReSS model has a total rainfall production closest to the observation but a large number of smaller objects, resulting in more frequent and concentrated rainfall. In contrast, both WRF and NFS tend to under-forecast the number of objects and total rainfall, but with a higher proportion of bigger objects. Location errors inferred from object centroid locations appear in all three models, as CReSS, NFS, and WRF exhibit a tendency to simulate objects slightly south, east, and northwest with respect to the observation. Most rainfall objects are aligned close to an E–W direction in CReSS, in best agreement with the observation, but many towards the NE–SW direction in both WRF and NFS. For each model, the objects are matched with the observed ones, and the results of the matched pairs are also discussed. Overall, though preliminarily, the CReSS model, with a finer grid size, emerges as best performing model for Mei-yu QPFs.

scholarly journals Evaluation of Rainfall Forecasts by Three Mesoscale Models during the Mei-yu Season of 2008 in Taiwan. Part II: Development of an Object-Oriented Method

Atmosphere ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 939
Author(s):  
Chung-Chieh Wang ◽  
Sahana Paul ◽  
Dong-In Lee
Keyword(s):  
Object Oriented ◽  
Tropical Rainfall Measuring Mission ◽  
Rain Gauge ◽  
Object Oriented Method ◽  
Rain Area ◽  
Mesoscale Models ◽  
Frequency Distributions ◽  
South West Monsoon ◽  
Blended Data ◽  
Traditional Approaches

This study describes a recently developed object-oriented method suitable for Taiwan for the purpose to verify quantitative precipitation forecasts (QPFs) produced by mesoscale models as a complement to the traditional approaches in existence. Using blended data from the rain-gauge network in Taiwan and the Tropical Rainfall Measuring Mission (TRMM) as the observation, the method developed herein is applied to twice-daily 0–48 h QPFs produced by the Cloud-Resolving Storm Simulator (CReSS) during the South-West Monsoon Experiment (SoWMEX) in May–June 2008. In this method, rainfall objects are identified through a procedure that includes smoothing and thresholding. Various attribute parameters and the characteristics of observed and forecast rain-area objects are then compared and discussed. Both the observed and the QPF frequency distributions of rain-area objects with respect to total water production, object size, and rainfall are similar to chi-distribution, with highest frequency at smaller values and decreased frequencies toward greater values. The model tends to produce heavier rainfall than observation, while the latter exhibits a higher percentage of larger objects with weaker rainfall intensity. The distributions of shape-related attributes are similar between QPF and observed rainfall objects, with more northeast–southwest oriented and fewer northwest–southeast oriented objects. Both observed and modeled object centroid locations have relative maxima over the terrain of Taiwan, indicating reasonable response to the topography. The above results are consistent with previous studies.

Object-Based Analysis and Verification of WRF Model Precipitation in the Low- and Midlatitude Pacific Ocean

2010 ◽  
Vol 138 (12) ◽  
pp. 4561-4575 ◽  
Author(s):  
Gregor Skok ◽  
Joe Tribbia ◽  
Jože Rakovec
Keyword(s):  
Pacific Ocean ◽  
Wrf Model ◽  
Tropical Rainfall Measuring Mission ◽  
Weather Research And Forecasting ◽  
Object Based ◽  
Evaluation Mode ◽  
Westward Movement ◽  
Object Trajectories ◽  
Model Precipitation ◽  
Trmm 3B42

Abstract An extended version of the Method for Object-based Diagnostic Evaluation (MODE) was used to perform a verification of precipitation provided by the Weather Research and Forecasting (WRF) model Tropical Channel Simulation (performed by NCAR). Model 3-hourly precipitation accumulations were compared to the Tropical Rainfall Measuring Mission (TRMM) 3B42 satellite-derived precipitation in the low- and midlatitude Pacific Ocean during 1998–2000. Overall, the spatial distribution of annual mean precipitation (i.e., the clear shape of the ITCZ with two maxima—one located in the east and one in the west) was reproduced well by the WRF model; however, there was considerably more precipitation in the WRF simulation than in the TRMM dataset. Object-based analysis identified more precipitation objects with life spans less than 30 h and fewer objects with life spans longer than 60 h in the TRMM dataset compared to the WRF simulation. Objects with the longest life span (>90 h) tended to occur in similar regions in both the modeled and satellite-derived datasets. Two of these regions were in the western part of the domain and one was in the eastern portion of the ITCZ, although these regions did not necessarily coincide with the regions of maximum precipitation accumulations. Both datasets had mostly eastward movement in the midlatitudes. The datasets, however, diverged around the central part of the ITCZ where the TRMM dataset displayed both eastward and westward movement, while westward movement was dominant in the WRF simulation. The analysis also showed that precipitation object trajectories were smoother in the model than in the TRMM dataset.

scholarly journals Applicability of TRMM Precipitation for Hydrologic Modeling in a Basin in the Northeast Brazilian Agreste

2018 ◽  
Vol 33 (1) ◽  
pp. 57-64
Author(s):  
Marcus Aurélio Soares Cruz ◽  
Leonardo Teixeira Rocha ◽  
Ricardo de Aragão ◽  
André Quintão de Almeida
Keyword(s):  
Remote Sensing ◽  
Comparative Analysis ◽  
Hydrologic Modeling ◽  
Tropical Rainfall Measuring Mission ◽  
Precipitation Regime ◽  
Total Rainfall ◽  
Northeast Region ◽  
Rain Gauges ◽  
Trmm Precipitation ◽  
Trmm 3B42

Abstract Determining precipitation using remote sensing is gaining space in hydrologic studies, helping make up for the lack of data in many regions of Brazil. The products from satellite TRMM (Tropical Rainfall Measuring Mission) are widely applied in studies in Brazil, but there are still few results about their applicability for hydrologic modeling in the Northeast Region, which is characterized by an irregular precipitation regime. The objective of this study is to evaluate the feasibility of using the TRMM 3B42 V7 data for hydrologic modeling in the Japaratuba river basin in Sergipe at three timescales: daily, every ten days, and monthly. The comparative analysis between the rainfall data from rain gauges and TRMM did not indicate satisfactory adequacy at these studied scales, since the TRMM data underestimated the total rainfall for all stations used in the study. However, for the hydrologic modeling, acceptable values were obtained for the efficiency coefficients evaluated only for the ten-day and monthly scales.

scholarly journals An Evaluation of WRF Rainfall Forecasts in Taiwan during Three Mei-Yu Seasons from 2008 to 2010

2017 ◽  
Vol 32 (4) ◽  
pp. 1329-1351 ◽  
Author(s):  
Chung-Chieh Wang ◽  
Fang-Ching Chien ◽  
Sahana Paul ◽  
Dong-In Lee ◽  
Pi-Yu Chuang
Keyword(s):  
Diurnal Cycle ◽  
Monsoon Rainfall ◽  
Wrf Model ◽  
Rainfall Amount ◽  
Weather Research And Forecasting ◽  
Intraseasonal Variation ◽  
Total Rainfall ◽  
Skill Levels ◽  
Rain Gauges ◽  
Verification Methods

Abstract The performance of the Weather Research and Forecasting (WRF) Model in quantitative precipitation forecasts (QPFs) across Taiwan during three mei-yu seasons between 2008 and 2010 is evaluated using observations from about 400 rain gauges. The QPFs, spanning a range of 12–36 h and run for two nested domains at grid sizes of 15 and 5 km, are verified. Both visual and statistical-based verification methods are used to provide complementary results. More emphasis is placed on intraseasonal variation and the diurnal cycle of mei-yu rainfall, as these aspects have been less well explored previously. While the categorical statistics indicate skill levels comparable to past studies, the model performs better for frontal rainfall in May than monsoon rainfall in June. The two WRF domains are found to capture the overall rainfall amount, its general spatial pattern, the increased rain from May to June, and the basic diurnal cycle to a reasonable extent. However, both domains exhibit a persistent eastward shift in rainfall areas throughout the season, from the upwind slope to near the ridge, mainly because of excessive daytime rainfall over the mountains that starts and ends too early (more so in June), combined with insufficient rainfall upstream (in plains and slopes) since the morning. Also, the 15-km domain has total rainfall amounts closer to the observations, but the 5-km domain suffers a larger underforecast with rainfall only at the resolvable scale. Despite this, the finer mesh is more capable of predicting the peak values and local variations in rainfall and, thus, has the same skill with higher hit percentages, especially toward the high thresholds.

Sheaf semantics for concurrent interacting objects

1992 ◽  
Vol 2 (2) ◽  
pp. 159-191 ◽  
Author(s):  
Joseph A. Goguen
Keyword(s):  
Computer Security ◽  
Object Oriented ◽  
Continuous Linear ◽  
Sheaf Theory ◽  
Electrical Circuits ◽  
Object Based ◽  
Time Concepts ◽  
Hardware Description ◽  
Description Languages ◽  
Object Oriented Systems

This paper uses concepts from sheaf theory to explain phenomena in concurrent systems, including object, inheritance, deadlock, and non-interference, as used in computer security. The approach is very; general, and applies not only to concurrent object oriented systems, but also to systems of differential equations, electrical circuits, hardware description languages, and much more. Time can be discrete or continuous, linear or branching, and distribution is allowed over space as well as time. Concepts from categpru theory help to achieve this generality: objects are modelled by sheaves; inheritance by sheaf morphisms; systems by diagrams; and interconnection by diagrams of diagrams. In addition, behaviour is given by limit, and the result of interconnection by colimit. The approach is illustrated with many examples, including a semantics for a simple concurrent object-based programming language.

‘No Small Share of Ingenuity’: An Object-Oriented Analysis of Eighteenth-Century English Dressmaking

Costume ◽  
2021 ◽  
Vol 55 (2) ◽  
pp. 186-211
Author(s):  
Carolyn Dowdell
Keyword(s):  
Eighteenth Century ◽  
Object Oriented ◽  
Women's Work ◽  
Secondary Source ◽  
Women’S Work ◽  
Object Based ◽  
Research Findings ◽  
Source Materials ◽  
Object Oriented Analysis

This article details eighteenth-century English dressmaking through an in-depth, object-oriented exploration of garment construction practices and techniques from a maker's perspective. Building upon prior scholarship of women's work and aspects of pre-industrial English garment trades, this article employs primary and secondary source materials in conjunction with extensive object-based research of extant garments. The research findings outline exactly how pre-industrial English dressmakers’ skills were nuanced, sophisticated and adaptive to making and remaking, as well as the personal, haptic connections they cultivated with their work.

scholarly journals Design and Realization of Shooting Virtual Training System for UAV-borne Missile

2021 ◽  
Vol 2083 (3) ◽  
pp. 032057
Author(s):  
Shicong Lin ◽  
Xin Tang ◽  
Wanlin Lu ◽  
Zehui Liu
Keyword(s):  
Design Method ◽  
Object Oriented ◽  
Simulation System ◽  
Training System ◽  
Visual Simulation ◽  
Virtual Training ◽  
Object Oriented Design ◽  
Training Costs ◽  
Object Based ◽  
Training Efficiency

Abstract UAV-borne missile is effective weapon to attack enemy ground targets. It is expensive, costly and difficult to live-fire drill. Using virtual training instead of actual training can greatly improve the training efficiency and the combat effectiveness. The article regards the operation training of a certain type of UAV-borne missile shooting training as the research object, based on the development of a visual simulation system for UAV-borne missile, uses the object-oriented design method to design a virtual training system based on LabVIEW. The system can realize the shooting operation training of trainees in a virtual environment, and achieve the goals of reduce training costs; improve training efficiency and shorten training period.

scholarly journals Assimilation of Satellite-Based Data for Hydrological Mapping of Precipitation and Direct Runoff Coefficient for the Lake Urmia Basin in Iran

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1624 ◽  
Author(s):  
Akbari ◽  
Haghighi ◽  
Aghayi ◽  
Javadian ◽  
Tajrishy ◽  
...  
Keyword(s):  
Tropical Rainfall Measuring Mission ◽  
Curve Number ◽  
Rain Gauge ◽  
Runoff Coefficient ◽  
Lake Urmia ◽  
Direct Runoff ◽  
Rain Gauges ◽  
Elevation Model ◽  
High Elevations ◽  
Service Curve

Water management in arid basins often lacks sufficient hydro-climatological data because, e.g., rain gauges are typically absent at high elevations and inflow to ungauged areas around large closed lakes is difficult to estimate. We sought to improve precipitation and runoff estimation in an arid basin (Lake Urmia, Iran) using methods involving assimilation of satellite-based data. We estimated precipitation using interpolation of rain gauge data by kriging, downscaling the Tropical Rainfall Measuring Mission (TRMM), and cokriging interpolation of in-situ records with Remote Sensing (RS)-based data. Using RS-based data application in estimations gave more precise results, by compensating for lack of data at high elevations. Cokriging interpolation of rain gauges by TRMM and Digitized Elevation Model (DEM) gave 4–9 mm lower Root Mean Square Error (RMSE) in different years compared with kriging. Downscaling TRMM improved its accuracy by 14 mm. Using the most accurate precipitation result, we modeled annual direct runoff with Kennessey and Soil Conservation Service Curve Number (SCS-CN) models. These models use land use, permeability, and slope data. In runoff modeling, Kennessey gave higher accuracy. Calibrating Kennessey reduced the Normalized RMSE (NRMSE) from 1 in the standard model to 0.44. Direct runoff coefficient map by 1 km spatial resolution was generated by calibrated Kennessey. Validation by the closest gauges to the lake gave a NRMSE of 0.41 which approved the accuracy of modeling.

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