scholarly journals EFFECT OF TRANSLATE SPEED OF TYPHOONS ON WIND WAVES

2020 ◽  
pp. 14
Author(s):  
Naoto Inagaki ◽  
Tomoya Shibayama ◽  
Miguel Esteban ◽  
Tomoyuki Takabatake
Keyword(s):  
Tropical Cyclones ◽  
Empirical Model ◽  
Wind Field ◽  
Meteorological Data ◽  
Wind Waves ◽  
Coupled Model ◽  
Wind Generation ◽  
Translation Speed ◽  
Different Types ◽  
Quantitative Assessments

Quantitative assessments of the effect that changes in the translate speed of typhoons have on wind waves were carried out. A WRF-SWAN coupled model that used observed meteorological data was applied to eight different typhoons in the vicinity of Shiono-Misaki, Japan. The authors proposed a new methodology to modify the translate speed and wind field of tropical cyclones, using an empirical model in which the gross wind field is expressed as the summation of two different types of wind generation (due to either the pressure gradient or translation speed). As a result, it is important to raise awareness of the future problems that can be caused by large storms that stall for prolonged periods of time.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/oCSbyaYoNEc

scholarly journals Propagation Directions of Ocean Surface Waves inside Tropical Cyclones

2018 ◽  
Vol 48 (7) ◽  
pp. 1495-1511 ◽  
Author(s):  
Paul A. Hwang ◽  
Edward J. Walsh
Keyword(s):  
Wave Propagation ◽  
Tropical Cyclones ◽  
Wind Field ◽  
Rapid Change ◽  
Primary System ◽  
Coverage Area ◽  
Multiple Wave ◽  
Translation Speed ◽  
Single Wave ◽  
The Right

AbstractSurface wave propagation inside tropical cyclones (TCs) is complicated and multiple wave systems are frequently observed. The directional wave spectra acquired by hurricane hunters are analyzed to quantify its azimuthal and radial variations. Referenced to the hurricane heading, the dominate feature in the front half of the TC coverage area is single wave systems propagating toward left and left-front. Multiple wave systems are generally observed in the back and right quarters outside the radius of maximum wind (RMW). The directional differences and locations of occurrences of multisystem spectra are Gaussian distributed. The directional differences of the secondary and tertiary wave systems from the primary system are centered around 60°–70°. The minor systems are more likely on the left-hand side of the primary system than on the right-hand side by a 3-to-1 ratio. The most likely azimuthal location of multisystem spectra is about 210° counterclockwise from the heading. In the right-front quarter, waves propagate into the advancing wind field and experience extended air–sea exchanges to grow higher and longer; in the left-rear quarter, they propagate away from the advancing wind field and are more likely younger seas. The radial variation of wave propagation is relatively minor except inside the RMW. A model describing the dominant wave propagation direction is presented. The regression statistics between modeled and measured wave directions show consistent agreement in 9 of the 11 datasets available for investigation. Causes for the significantly different statistics of the two remaining datasets include proximity to coast (a landfalling case) and rapid change in the hurricane translation speed or direction.

scholarly journals Improving Parametric Cyclonic Wind Fields Using Recent Satellite Remote Sensing Data

2018 ◽  
Author(s):  
Yann Krien ◽  
Gaël Arnaud ◽  
Raphaël Cécé ◽  
Jamal Khan ◽  
Ali Bel Madani ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Tropical Cyclones ◽  
Satellite Remote Sensing ◽  
Wind Waves ◽  
Surface Wind ◽  
Coupled Model ◽  
Remote Sensing Data ◽  
Parametric Models ◽  
Substantial Part ◽  
Wind Fields

Parametric cyclonic wind fields are widely used worldwide for insurance risk underwriting, coastal planning, or storm surge forecasts. They support high-stakes financial, development, and emergency decisions. Yet, there is still no consensus on the best parametric approach, or relevant guidance to choose among the great variety of published models. The aim of this paper is first and foremost to demonstrate that recent progresses on estimating extreme surface wind speeds from satellite remote sensing now makes it possible to select the best option with greater objectivity. In particular, we show that the Cyclone Global Navigation Satellite System (CYGNSS) mission of NASA is able to capture a substantial part of the tropical cyclones structure, and allows identifying systematic biases in a number of parametric models. Our results also suggest that none of the traditional empirical approaches can be considered as the best option in all cases. Rather, the choice of a parametric model depends on several criteria such as cyclone intensity and/or availability of wind radii information. The benefit of our approach is demonstrated by comparing traditional models with an improved vortex for hurricane Maria in the Caribbean. The wave heights computed by a wave-current hydrodynamic coupled model are found to be much better reproduced, with a significant reduction of the model biases. The results and approach presented in this study should shed new light on how to handle parametric cyclonic wind models. This will help the scientific community to conduct better wind, waves and surge analysis for tropical cyclones.

Study on Synthesized Wind in the Numerical Simulation of Wind Waves

2014 ◽  
Vol 638-640 ◽  
pp. 1274-1279 ◽  
Author(s):  
Luo Bin Jin ◽  
Yuan Li ◽  
Lian Song Liang
Keyword(s):  
Tropical Cyclones ◽  
Wind Field ◽  
Wind Waves ◽  
Mean Deviation ◽  
Maximum Deviation ◽  
Wave Processes ◽  
Satellite Altimeter ◽  
Storm Wave ◽  
Simulation Results ◽  
Good Agreement

Numerical simulations are made for 10 storm wave processes during the period of 2008-2010, based on SWAN, with the Myers wind field, CCMP wind filed and the combination of the two as the storm driving wind field respectively. The results are compared with the observations from Jason-1 satellite altimeter during tropical cyclones (TCs). It indicates that Myers wind field makes a good agreement with measured values near the TC center, while CCMP wind field makes a good agreement with measured values far away from the TC center. Synthesis of the wind field combines the merit of the Myers wind field and CCMP wind field, and it is more in line with the wind field distribution; the simulation results of synthesized wind field make a good agreement with the measured results, with maximum deviation of -0.62m, mean deviation of -0.11m.

scholarly journals Sea Surface Salinity Response to Tropical Cyclones Based on Satellite Observations

2021 ◽  
Vol 13 (3) ◽  
pp. 420
Author(s):  
Jingru Sun ◽  
Gabriel Vecchi ◽  
Brian Soden
Keyword(s):  
Tropical Cyclones ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Surface Salinity ◽  
Translation Speed ◽  
Salinity Stratification ◽  
Left Hand ◽  
In Situ Data ◽  
Salinity Response ◽  
The Right

Multi-year records of satellite remote sensing of sea surface salinity (SSS) provide an opportunity to investigate the climatological characteristics of the SSS response to tropical cyclones (TCs). In this study, the influence of TC winds, rainfall and preexisting ocean stratification on SSS evolution is examined with multiple satellite-based and in-situ data. Global storm-centered composites indicate that TCs act to initially freshen the ocean surface (due to precipitation), and subsequently salinify the surface, largely through vertical ocean processes (mixing and upwelling), although regional hydrography can lead to local departure from this behavior. On average, on the day a TC passes, a strong SSS decrease is observed. The fresh anomaly is subsequently replaced by a net surface salinification, which persists for weeks. This salinification is larger on the right (left)-hand side of the storm motion in the Northern (Southern) Hemisphere, consistent with the location of stronger turbulent mixing. The influence of TC intensity and translation speed on the ocean response is also examined. Despite having greater precipitation, stronger TCs tend to produce longer-lasting, stronger and deeper salinification especially on the right-hand side of the storm motion. Faster moving TCs are found to have slightly weaker freshening with larger area coverage during the passage, but comparable salinification after the passage. The ocean haline response in four basins with different climatological salinity stratification reveals a significant impact of vertical stratification on the salinity response during and after the passage of TCs.

Simulation of the wind fields over complex terrain with coupling of CFD and WRF

2021 ◽  
pp. 1-12
Author(s):  
Xiaoyu Luo ◽  
Yiwen Cao
Keyword(s):  
Wind Speed ◽  
Wind Field ◽  
Complex Terrain ◽  
Civil Engineering ◽  
Meteorological Data ◽  
Mass Conservation ◽  
Coupling Method ◽  
Wind Fields ◽  
Civil Structures ◽  
Civil Engineers

In the field of civil engineering, the meteorological data available usually do not have the detailed information of the wind near a certain site. However, the detailed information of the wind field during typhoon is important for the wind-resistant design of civil structures. Furthermore, the resolution of the meteorological data available by the civil engineers is too coarse to be applicable. Therefore it is meaningful to obtain the detailed information of the wind fields based on the meteorological data provided by the meteorological department. Therefore, in the present study, a one-way coupling method between WRF and CFD is adopted and a method to keep the mass conservation during the simulation in CFD is proposed. It is found that using the proposed one-way coupling method, the predicted wind speed is closer to the measurement. And the curvature of the wind streamline during typhoon is successfully reproduced.

scholarly journals Empirical model based on meteorological parameters to estimate the global solar radiation in Nepal

BIBECHANA ◽  
2014 ◽  
Vol 11 ◽  
pp. 25-33
Author(s):  
Krishna R Adhikari ◽  
Shekhar Gurung ◽  
Binod K Bhattarai
Keyword(s):  
Solar Radiation ◽  
Empirical Model ◽  
Meteorological Data ◽  
Cost Effective ◽  
Developed Countries ◽  
Global Solar Radiation ◽  
Develop Model ◽  
Sunshine Hours ◽  
Linear Regression Technique ◽  
Meteorological Characteristic

Solar radiation is the best option and cost effective energy resources of this globe. Only a few stations are there in developing and under developed countries including Nepal to monitor solar radiation and sunshine hours to generate a rational and accurate solar energy database. In this study, daily global solar radiation, and ubiquitous meteorological data (temperature and relative humidity) rather than rarely available sunshine hours have been used for Biratnagar, Kathmandu, Pokhara and Jumla to derive regression constants and hence to develop an empirical model. The model estimated global solar radiation is found to be in close agreement with measured values of respective sites. The estimated values were compared with Angstrom-Prescott model and examined using the statistical tools. Thus, the linear regression technique can be used to develop model at any location in the world. The resultant model may then be used to estimate the missing data of solar radiation for the respective sites and also can be used to estimate global solar radiation for the locations of similar geographic and meteorological characteristic. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10376   BIBECHANA 11(1) (2014) 25-33

Description of Wind Field Dynamic Patterns in a Valley and Their Relation to Mesoscale and Synoptic-Scale Meteorological Situations

1995 ◽  
Vol 34 (1) ◽  
pp. 49-67 ◽  
Author(s):  
R. Guardans ◽  
I. Palomino
Keyword(s):  
Wind Field ◽  
Transition Probabilities ◽  
Meteorological Data ◽  
Atmospheric Dispersion ◽  
Synoptic Situation ◽  
Large Set ◽  
Valley Wind ◽  
Complete Collection ◽  
Emergency Plans ◽  
Synoptic Conditions

Abstract A large set of hourly meteorological data from seven towers deployed in Montesina Valley (Cordoba, Spain) is studied in relation to the prevailing synoptic situation. The complete collection of daily synoptic maps for 1985-90 has been classified in seven basic weather patterns. First-order transition probabilities and weatherpattern persistences have been calculated for each of the patterns. The behavior of the local valley wind field is described as a function of the synoptic patterns. The work reported here, based on observations of the characteristic time and space patterns of flow in the valley under different synoptic conditions, has made it possible to obtain a set of empirical rules and regression functions to produce forecasts of the local wind field as a function of the synoptic situation and the hour of the day to be used in the emergency plans. The result of this work is currently being implemented in an atmospheric dispersion module of an expert system that will be used as a tool to predict the evolution of accidental and routine hazardous emissions to the atmosphere in complex terrain such as valleys and coastal areas.

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