1/f/sup β/ noise-based real-time animation of trees swaying in wind fields

2004 ◽  
Author(s):  
S. Ota ◽  
M. Tamura ◽  
K. Fujita ◽  
T. Fujimoto ◽  
K. Muraoka ◽  
...  
Keyword(s):  
Real Time ◽  
Wind Fields

Analysis of the 6 September 2015 Tornadic Storm Around the Tokyo Metropolitan Area Using Coupled 3DVAR and Incremental Analysis Updates

2017 ◽  
Vol 12 (5) ◽  
pp. 956-966
Author(s):  
Ken-ichi Shimose ◽  
◽  
Shingo Shimizu ◽  
Ryohei Kato ◽  
Koyuru Iwanami
Keyword(s):  
Real Time ◽  
Metropolitan Area ◽  
Surface Wind ◽  
Three Dimensional ◽  
Incremental Analysis ◽  
Wind Fields ◽  
Real Time Processing ◽  
Tokyo Metropolitan ◽  
Tokyo Metropolitan Area ◽  
Real Time Analysis

This study reports preliminary results from the three-dimensional variational method (3DVAR) with incremental analysis updates (IAU) of the surface wind field, which is suitable for real-time processing. In this study, 3DVAR with IAU was calculated for the case of a tornadic storm using 500-m horizontal grid spacing with updates every 10 min, for 6 h. Radial velocity observations by eight X-band multi-parameter Doppler radars and three Doppler lidars around the Tokyo Metropolitan area, Japan, were used for the analysis. In this study, three types of analyses were performed between 1800 to 2400 LST (local standard time: UTC + 9 h) 6 September 2015. The first used only 3DVAR (3DVAR), the second used 3DVAR with IAU (3DVAR+IAU), and the third analysis did not use data assimilation (CNTL). 3DVAR+IAU showed the best accuracy of the three analyses, and 3DVAR alone showed the worst accuracy, even though the background was updated every 10 min. Sharp spike signals were observed in the time series of wind speed at 10 m AGL, analyzed by 3DVAR, strongly suggesting that a “shock” was caused by dynamic imbalance due to the instantaneous addition of analysis increments to the background wind components. The spike signal was not shown in 3DVAR+IAU analysis, therefore, we suggest that the IAU method reduces the shock caused by the addition of analysis increments. This study provides useful information on the most suitable DA method for the real-time analysis of surface wind fields.

scholarly journals Improved near real time surface wind resolution over the Mediterranean Sea

Ocean Science ◽  
2007 ◽  
Vol 3 (2) ◽  
pp. 259-271 ◽  
Author(s):  
A. Bentamy ◽  
H.-L. Ayina ◽  
P. Queffeulou ◽  
D. Croize-Fillon ◽  
V. Kerbaol
Keyword(s):  
Wind Speed ◽  
Mediterranean Sea ◽  
Real Time ◽  
Surface Wind ◽  
Surface Wind Speed ◽  
Remotely Sensed ◽  
Wind Fields ◽  
Remotely Sensed Data ◽  
Space And Time ◽  
The Mediterranean

Abstract. Several scientific programs, including the Mediterranean Forecasting System Toward Environmental Predictions (MFSTEP project), request high space and time resolutions of surface wind speed and direction. The purpose of this paper is to focus on surface wind improvements over the global Mediterranean Sea, based on the blending near real time remotely sensed wind observations and ECMWF wind analysis. Ocean surface wind observations are retrieved from QuikSCAT scatterometer and from SSM/I radiometers available at near real time at Météo-France. Using synchronous satellite data, the number of remotely sensed data available for each analysis epoch (00:00 h; 06:00 h; 12:00 h; 18:00 h) is not uniformly distributed as a function of space and time. On average two satellite wind observations are available for each analysis time period. The analysis is performed by optimum interpolation (OI) based on the kriging approach. The needed covariance matrixes are estimated from the satellite wind speed, zonal and meridional component observations. The quality of the 6-hourly resulting blended wind fields on 0.25° grid are investigated trough comparisons with the remotely sensed observations as well as with moored buoy wind averaged wind estimates. The blended wind data and remotely wind observations, occurring within 3 h and 0.25° from the analysis estimates, compare well over the global basin as well as over the sub-basins. The correlation coefficients exceed 0.95 while the rms difference values are less than 0.30 m/s. Using measurements from moored buoys, the high-resolution wind fields are found to have similar accuracy as satellite wind retrievals. Blended wind estimates exhibit better comparisons with buoy moored in open sea than near shore.

Predictability of the Madden–Julian Oscillation Estimated Using Observational Data

2010 ◽  
Vol 138 (3) ◽  
pp. 1004-1013 ◽  
Author(s):  
Ruiqiang Ding ◽  
Jianping Li ◽  
Kyong-Hwan Seo
Keyword(s):  
Real Time ◽  
Observational Data ◽  
Numerical Models ◽  
Longwave Radiation ◽  
Large Error ◽  
Madden Julian Oscillation ◽  
Wind Fields ◽  
Potential Predictability ◽  
Time Prediction ◽  
Real Time Analysis

Abstract Existing numerical models produce large error in simulating the Madden–Julian oscillation (MJO), thereby underestimating its predictability. In this paper, the predictability limit of the MJO is determined by the nonlinear local Lyapunov exponent approach, which provides an estimate of atmospheric predictability based on the observational data. The results show that the predictability limit of the MJO obtained from the bandpass-filtered (30–80 days) outgoing longwave radiation and wind fields, which serves as an empirical estimate of the theoretical potential predictability of the MJO, can exceed 5 weeks, which is well above the 1-week predictability of background noise caused by bandpass filtering. In contrast, a real-time analysis of MJO predictability using the real-time multivariate MJO (RMM) index, as introduced by Wheeler and Hendon, reveals a predictability limit of about 3 weeks. The findings reported here raise the possibility of obtaining a higher predictability limit in real-time prediction by improving the RMM index or by introducing a better method of extracting intraseasonal signals.

A hybrid method for real-time animation of trees swaying in wind fields

2004 ◽  
Vol 20 (10) ◽  
pp. 613-623 ◽  
Author(s):  
Shin Ota ◽  
Machiko Tamura ◽  
Tadahiro Fujimoto ◽  
Kazunobu Muraoka ◽  
Norishige Chiba
Keyword(s):  
Real Time ◽  
Hybrid Method ◽  
Wind Fields

scholarly journals A web-based wildfire simulator for operational applications

2019 ◽  
Vol 28 (2) ◽  
pp. 99 ◽  
Author(s):  
Bachisio Arca ◽  
Tiziano Ghisu ◽  
Marcello Casula ◽  
Michele Salis ◽  
Pierpaolo Duce
Keyword(s):  
User Interface ◽  
Real Time ◽  
Graphical User Interface ◽  
Computational Cost ◽  
Wind Fields ◽  
Wildfire Management ◽  
Web Based ◽  
Incident Command ◽  
Wildfire Suppression ◽  
Server Application

Wildfire simulators and decision support systems can assist the incident command teams in charge of tactical wildfire suppression. This paper presents a web-based wildfire simulator developed to provide real-time support for wildfire management. The paper describes the overall software architecture, the modelling chain characteristics and the results produced by the simulator considering a set of actual wildfires that occurred in the island of Sardinia, Italy. The simulator consists of a graphical user interface that deals with data input–output management, a mass-consistent model devoted to the downscaling of wind fields, and a module that provides a spatially explicit representation of wildfire propagation. The simulator is a client‐server application that is operated through a web-based graphical user interface that leaves the computational work to a dedicated server; most of the code is parallelised in order to minimise computational run-time. The validation phase demonstrated the capabilities of the simulator in providing wildfire predictions with a substantial agreement with actual wildfires, and a computational cost suitable for faster than real-time applications. The simulator is proposed as a tool to provide assistance to civil protection and fire management agencies during the incident response phase. The simulator is also appropriate for the training of personnel.

scholarly journals Improved near real time surface wind resolution over the Mediterranean Sea

2006 ◽  
Vol 3 (3) ◽  
pp. 435-470 ◽  
Author(s):  
A. Bentamy ◽  
H.-L. Ayina ◽  
P. Queffeulou ◽  
D. Croize-Fillon
Keyword(s):  
Wind Speed ◽  
Mediterranean Sea ◽  
Real Time ◽  
Surface Wind ◽  
Surface Wind Speed ◽  
Remotely Sensed ◽  
Wind Fields ◽  
Remotely Sensed Data ◽  
Space And Time ◽  
The Mediterranean

Abstract. Several scientific programs, including the Mediterranean Forecasting System Toward Environmental Predictions (MFSTEP project), request high space and time resolutions of surface wind speed and direction. The purpose of this paper is to focus on surface wind improvements over the global Mediterranean Sea, based on the blending near real time remotely sensed wind observations and ECMWF wind analysis. Ocean surface wind observations are retrieved from QuikSCAT scatterometer and from SSM/I radiometers available at near real time at Météo-France. Using synchronous satellite data, the number of remotely sensed data available for each analysis epoch (00:00 h; 06:00 h; 12:00 h; 18:00 h) is not uniformly distributed as a function of space and time. On average two satellite wind observations are available for each analysis time period. The analysis is performed by optimum interpolation (OI) based on the kriging approach. The needed covariance matrixes are estimated from the satellite wind speed, zonal and meridional component observations. The quality of the 6-hourly resulting blended wind fields on 0.25° grid are investigated trough comparisons with the remotely sensed observations as well as with moored buoy wind averaged wind estimates. The blended wind data and remotely wind observations, occurring within 3 h and 0.25° from the analysis estimates, compare well over the global basin as well as over the sub-basins. The correlation coefficients exceed 0.95 while the rms difference values are less than 0.30 m/s. Using measurements from moored buoys, the high-resolution wind fields are found to have similar accuracy as satellite wind retrievals. Blended wind estimates exhibit better comparisons with buoy moored in open sea than near shore.

A real-time assimilation algorithm applied to near-surface ocean wind fields

2008 ◽  
Vol 19 (3) ◽  
pp. 319-330 ◽  
Author(s):  
Anders Malmberg ◽  
Jan Holst ◽  
Ulla Holst
Keyword(s):  
Real Time ◽  
Wind Fields ◽  
Near Surface ◽  
Surface Ocean ◽  
Ocean Wind

Some Recent Results in Quiescent Prominence Spectrometry

1979 ◽  
Vol 44 ◽  
pp. 41-47
Author(s):  
Donald A. Landman
Keyword(s):  
Real Time ◽  
Computer System ◽  
Spectral Response ◽  
Absolute Intensity ◽  
Solar Observatory ◽  
Target Size ◽  
Small Target ◽  
Signal Averaging ◽  
Quiescent Prominence

This paper describes some recent results of our quiescent prominence spectrometry program at the Mees Solar Observatory on Haleakala. The observations were made with the 25 cm coronagraph/coudé spectrograph system using a silicon vidicon detector. This detector consists of 500 contiguous channels covering approximately 6 or 80 Å, depending on the grating used. The instrument is interfaced to the Observatory’s PDP 11/45 computer system, and has the important advantages of wide spectral response, linearity and signal-averaging with real-time display. Its principal drawback is the relatively small target size. For the present work, the aperture was about 3″ × 5″. Absolute intensity calibrations were made by measuring quiet regions near sun center.

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