scholarly journals TRANSFORMATION OF RANDOM BREAKING WAVES ON SURF BEAT

1986 ◽  
Vol 1 (20) ◽  
pp. 9 ◽  
Author(s):  
William R. Dally ◽  
Robert G. Dean
Keyword(s):  
Surf Zone ◽  
Wave Model ◽  
Breaking Waves ◽  
Wave Transformation ◽  
Random Wave ◽  
Data Sets ◽  
Data Set ◽  
Wave Decay ◽  
Mean Water Level ◽  
Good Agreement

Based on a previous study by the authors of regular breaking waves in the surf zone, a model for random wave transformation across the nearshore region is developed. The results of a laboratory investigation of the effect of a steady opposing current on the wave decay process are presented and a proposed governing equation verified. Surf beat effects on wave transformation are then included in the model by representing the long wave as a temporally and spatiallyvarying current and mean water level. The concept of an equivalent water depth, which contains the effect of the current, is introduced and then included in a stochastic form in the random wave model. Surf beat is found to noticeably increase the decay of the root mean square wave height, especially in the inner surf where the beat is strongest. Comparison of the models to two field data sets show very good agreement for Hotta and Mizuguchi (1980), but rather poor for Thornton and Guza (1983). Possible explanations for the unexpected behavior of the second data set, pertaining to filtering, are discussed. Finally, a possible explanation for the dependence of random wave decay on deepwater steepness, noted by Battjes and Stive (1985), is presented.

Spectral analysis and inversion of experimental codas

Geophysics ◽  
1993 ◽  
Vol 58 (3) ◽  
pp. 408-418 ◽  
Author(s):  
L. R. Jannaud ◽  
P. M. Adler ◽  
C. G. Jacquin
Keyword(s):  
Spectral Analysis ◽  
Characteristic Length ◽  
Gaussian Model ◽  
Seismic Survey ◽  
Data Sets ◽  
Data Set ◽  
Anisotropic Elastic ◽  
And Inversion ◽  
Good Agreement

A method developed for the determination of the characteristic lengths of an heterogeneous medium from the spectral analysis of codas is based on an extension of Aki’s theory to anisotropic elastic media. An equivalent Gaussian model is obtained and seems to be in good agreement with the two experimental data sets that illustrate the method. The first set was obtained in a laboratory experiment with an isotropic marble sample. This sample is characterized by a submillimetric length scale that can be directly observed on a thin section. The spectral analysis of codas and their inversion yields an equivalent correlation length that is in good agreement with the observed one. The second data set is obtained in a crosshole experiment at the usual scale of a seismic survey. The codas are recorded, analysed, and inverted. The analysis yields a vertical characteristic length for the studied subsurface that compares well with the characteristic length measured by seismic and stratigraphic logs.

Extended energy-balance-equation wave model for multidirectional random wave transformation

2005 ◽  
Vol 32 (8-9) ◽  
pp. 961-985 ◽  
Author(s):  
Hajime Mase ◽  
Kazuya Oki ◽  
Terry S. Hedges ◽  
Hua Jun Li
Keyword(s):  
Energy Balance ◽  
Balance Equation ◽  
Wave Model ◽  
Energy Balance Equation ◽  
Wave Transformation ◽  
Random Wave

Numerical Simulation of Wave Transformation Using Spectral Wave Action Model

2014 ◽  
Vol 638-640 ◽  
pp. 1261-1265 ◽  
Author(s):  
Yun Peng Zhang ◽  
Ming Liang Zhang ◽  
Zi Ning Hao ◽  
Yuan Yuan Xu ◽  
Yang Qiao
Keyword(s):  
Coastal Waters ◽  
Real Life ◽  
Wave Model ◽  
Wave Action ◽  
Wave Transformation ◽  
Wind Effect ◽  
Random Wave ◽  
Action Model ◽  
Averaged Model ◽  
Transformation Processes

This paper presents a spectral wave action model to simulate random wave deformation and transformation. The wave model is based on the wave action balance equation and can simulate wave fields by accounting for wave breaking, shoaling, refraction, diffraction and wind effect in coastal waters. It is a finite-difference, phase averaged model for the steady-state wave spectral transformation. The wave model is applied to verify different experimental cases and real life case of considering the several factor effects. The calculated results agree with the experimental and field data. The results show that the wave model presented herein should be useful in simulating the wave transformation processes in complicated coastal waters.

scholarly journals Global validation of improved SCIAMACHY scientific ozone limb data using ozonesonde measurements

2015 ◽  
Vol 8 (5) ◽  
pp. 4817-4858
Author(s):  
J. Jia ◽  
A. Rozanov ◽  
A. Ladstätter-Weißenmayer ◽  
J. P. Burrows
Keyword(s):  
Global Scale ◽  
Data Sets ◽  
Vertical Profiles ◽  
Data Set ◽  
Latitude Range ◽  
Ozone Profile ◽  
The Tropics ◽  
Relative Differences ◽  
Significant Underestimation ◽  
Good Agreement

Abstract. In this manuscript, the latest SCIAMACHY limb ozone scientific vertical profiles, namely the current V2.9 and the upcoming V3.0, are extensively compared with ozone sonde data from the WOUDC database. The comparisons are made on a global scale from 2003 to 2011, involving 61 sonde stations. The retrieval processors used to generate V2.9 and V3.0 data sets are briefly introduced. The comparisons are discussed in terms of vertical profiles and stratospheric partial columns. Our results indicate that the V2.9 ozone profile data between 20–30 km is in good agreement with ground based measurements with less than 5% relative differences in the latitude range of 90° S–40° N (with exception of the tropical Pacific region where an overestimation of more than 10% is observed), which corresponds to less than 5 DU partial column differences. In the tropics the differences are within 3%. However, this data set shows a significant underestimation northwards of 40° N (up to ~15%). The newly developed V3.0 data set reduces this bias to below 10% while maintaining a good agreement southwards of 40° N with slightly increased relative differences of up to 5% in the tropics.

scholarly journals TIME DOMAIN COMPARISONS OF MEASURED AND SPECTRALLY SIMULATED BREAKING WAVES

2017 ◽  
pp. 12
Author(s):  
Mustafa Kemal Ozalp ◽  
Serdar Beji
Keyword(s):  
Time Domain ◽  
Surf Zone ◽  
Field Measurements ◽  
Wave Model ◽  
Breaking Waves ◽  
Irregular Waves ◽  
Dissipative Effects ◽  
Spectral Components ◽  
Breaking Mechanism ◽  
Acceptable Agreement

For realistic wave simulations in the nearshore zone besides nonlinear interactions, the dissipative effects of wave breaking must also be taken into account. This paper presents the applications of a spectral nonlinear wave model with a dissipative breaking mechanism introduced by Beji and Nadaoka (1997). Results obtained for spectral components are converted to the time series and compared with Beji and Battjes' (1993) laboratory measurements and the field measurements of Nakamura and Katoh (1992) in the surf zone. While the model predicts the spilling-type breaking of irregular waves in acceptable agreement with the measurements in time domain, the agreement is unsatisfactory for plunging-type breakers.

scholarly journals Comparison of 14C Ages Between LSC and AMS Measurements of Choukai Jindai Cedar Tree Rings at 2600 cal BP

Radiocarbon ◽  
2010 ◽  
Vol 52 (3) ◽  
pp. 895-900 ◽  
Author(s):  
Yui Takahashi ◽  
Hirohisa Sakurai ◽  
Kayo Suzuki ◽  
Taiichi Sato ◽  
Shuichi Gunji ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tree Rings ◽  
Liquid Scintillation ◽  
Measurement Methods ◽  
Scintillation Counting ◽  
Age Difference ◽  
Data Sets ◽  
Data Set ◽  
The Difference ◽  
Good Agreement

Radiocarbon ages of Choukai Jindai cedar tree rings growing in the excess era of 14C concentrations during 2757–2437 cal BP were measured using 2 types of 14C measurement methods, i.e. liquid scintillation counting (LSC) and accelerator mass spectrometry (AMS). The difference between the 2 methods is 3.7 ± 5.2 14C yr on average for 61 single-year tree rings, indicating good agreement between the methods. The Choukai data sets show a small sharp bump with an average 14C age of 2497.1 ± 3.0 14C yr BP during 2650–2600 cal BP. Although the profile of the Choukai LSC data set compares well with that of IntCal04, having a 14C age difference of 4.6 ± 5.3 14C yr on average, the Choukai LSC 14C ages indicate variability against the smoothed profile of IntCal04.

scholarly journals Modeling the Impact of the Implementation of a Submerged Structure on Surf Zone Sandbar Dynamics

2019 ◽  
Vol 7 (4) ◽  
pp. 117 ◽  
Author(s):  
Clément Bouvier ◽  
Bruno Castelle ◽  
Yann Balouin
Keyword(s):  
Surf Zone ◽  
Breaking Waves ◽  
Submerged Breakwater ◽  
Defense Strategies ◽  
Adverse Impacts ◽  
Limited Effectiveness ◽  
Coastal Defense ◽  
Moderate Energy ◽  
The Impact ◽  
Good Agreement

Coastal defense strategies based on structures are increasingly unpopular as they are costly, leave lasting scars on the landscape, and sometimes have limited effectiveness or even adverse impacts. While a clear improvement concerning aesthetic considerations using soft submerged breakwater is undeniable, their design has often focused on wave transmission processes across the crest of the structure, overlooking short- to medium-term morphodynamic responses. In this study, we used a time- and depth-averaged morphodynamic model to investigate the impact of the implementation of a submerged breakwater on surf zone sandbar dynamics at the beach of Sète, SE France. The hydrodynamic module was calibrated with data collected during a field experiment using three current profilers deployed to capture rip-cell circulation at the edge of the structure. The model showed good agreement with measurements, particularly for the longshore component of the flow (RMSE = 0.07 m/s). Results showed that alongshore differential wave breaking at the edge of the submerged breakwater drove an intense (0.4 m/s) two-dimensional circulation for low- to moderate-energy waves. Simulations indicated that inner-bar rip channel development, which was observed prior to the submerged reef implementation, was inhibited in the lee of the structure as rip-cell circulation across the inner bar disappeared owing to persistently low-energy breaking waves. The cross-shore sandbar dynamics in the lee of the structure were also impacted due to the drastic decrease of the offshore-directed flow over the inner-bar during energetic events. This paper highlights that implementation of a submerged breakwater results in larges changes in nearshore hydrodynamics that, in turn, can affect overall surf zone sandbar behavior.

Big commercial microwave link data: Detecting rain events with deep learning

2020 ◽  
Author(s):  
Julius Polz ◽  
Christian Chwala ◽  
Maximilian Graf ◽  
Harald Kunstmann
Keyword(s):  
Time Series ◽  
Rain Rate ◽  
Data Sets ◽  
Data Set ◽  
Quantitative Precipitation Estimation ◽  
Precipitation Estimation ◽  
Signal Fluctuation ◽  
Rain Events ◽  
Microwave Link ◽  
Good Agreement

<p>Commercial microwave links (CMLs) can be used for quantitative precipitation estimation. The measurement technique is based on the exploitation of the close to linear relationship between the attenuation of the signal level by rainfall and the path averaged rain rate. At a temporal resolution of one minute, the signal level of almost 4000 CMLs distributed all over Germany is being recorded since August 2017, resulting in one of the biggest CML data sets available for scientific purposes. A crucial step for retrieving rainfall information from this large CML data set is to accurately detect rainy periods in the time-series, a process which is hampered by strong signal fluctuations, occasionally occurring even when there is no rain. In our study, we evaluate the performance of convolutional neural networks (CNNs) to distinguish between rainy and non-rainy signal fluctuations by recognizing their specific patterns. CNNs make use of many layers and local connections of neurons to recognize patterns independent of their location in the time-series. We designed a custom CNN architecture consisting of a feature extraction and classification part with 20 layers of neurons and 1.4 x 10<sup>5</sup> trainable parameters. To train the model and validate the results we refer to the gauge-adjusted radar product RADOLAN-RW, provided by the German meteorological service. Despite not being an absolute truth, it provides robust information about rain events at the CML locations at an hourly time resolution. With only 400 CMLs used for training and 3504 for validation, we find that CNNs can learn to recognize different signal fluctuation patterns and generalize well to sensors and time periods not used for training. Overall we find a good agreement between the CML and weather radar derived rainfall information by detecting on average 87 % of all rainy and 91 % of all non-rainy periods.</p>

scholarly journals Analysis of High-Throughput Flow Cytometry Data Using plateCore

2009 ◽  
Vol 2009 ◽  
pp. 1-10 ◽  
Author(s):  
Errol Strain ◽  
Florian Hahne ◽  
Ryan R. Brinkman ◽  
Perry Haaland
Keyword(s):  
Flow Cytometry ◽  
High Throughput ◽  
Negative Control ◽  
Data Sets ◽  
Data Set ◽  
Flow Cytometry Data ◽  
Open Platform ◽  
Screening Experiments ◽  
Software Packages ◽  
Good Agreement

Flow cytometry (FCM) software packages from R/Bioconductor, such as flowCore and flowViz, serve as an open platform for development of new analysis tools and methods. We created plateCore, a new package that extends the functionality in these core packages to enable automated negative control-based gating and make the processing and analysis of plate-based data sets from high-throughput FCM screening experiments easier. plateCore was used to analyze data from a BD FACS CAP screening experiment where five Peripheral Blood Mononucleocyte Cell (PBMC) samples were assayed for 189 different human cell surface markers. This same data set was also manually analyzed by a cytometry expert using the FlowJo data analysis software package (TreeStar, USA). We show that the expression values for markers characterized using the automated approach in plateCore are in good agreement with those from FlowJo, and that using plateCore allows for more reproducible analyses of FCM screening data.

Regularizing 3-D data sets with DMO

Geophysics ◽  
1996 ◽  
Vol 61 (4) ◽  
pp. 1103-1114 ◽  
Author(s):  
Anat Canning ◽  
Gerald H. F. Gardner
Keyword(s):  
Computer Program ◽  
Seismic Data ◽  
Physical Modeling ◽  
Data Sets ◽  
Angle Of Incidence ◽  
Data Set ◽  
Velocity Function ◽  
Inherent Problem ◽  
Original Acquisition ◽  
Good Agreement

The combination of DMO and [Formula: see text] is used here to change the original acquisition geometry of a 3-D seismic data set into a more convenient form. For example, irregular 3-D surveys can be projected onto a regular midpoint‐offset grid with zero source‐receiver azimuth and equal increments in offset. The algorithm presented here is based on a new, nonaliased 3-D DMO algorithm in (f, x) domain. It does not require any knowledge of the velocity function for constant or rms velocity variations. The computer program was designed to process and to output very large multifold 3-D data sets. A synthetic example of a point diffractor in 3-D space and a 3-D experiment in a physical modeling tank are used to demonstrate the procedure. In both cases, the results obtained after the data set is regularized are compared with a data set that was acquired initially with the desired configuration. These comparisons show very good agreement. Analysis of the procedure indicates that it may not reconstruct AVO correctly. This is an inherent problem that occurs because the reorganization procedure changes the angle of incidence.

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