scholarly journals Simulation of the Structure and Track of the Tropical Cyclone Sidr using Numerical Models

2016 ◽  
Vol 8 (2) ◽  
pp. 129-147
Author(s):  
M. A. E. Akhter ◽  
M. M. Alam ◽  
M. A. K. Mallik
Keyword(s):  
Tropical Cyclone ◽  
Numerical Models ◽  
Wrf Model ◽  
Horizontal Resolution ◽  
Forecast Skill ◽  
Cyclonic Storm ◽  
Mesoscale Models ◽  
Cyclone Sidr ◽  
Tropical Oceans ◽  
The Indian Ocean

Tropical cyclone (TC), one of the most devastating and deadly weather phenomena,is a result of organized intense convective activities over warm tropical oceans. In the recent years, mesoscale models are extensively used for simulation of genesis, intensification and movement of tropical cyclones. During 09-16 November, 2007, a severe cyclonic storm named, Sidr was active in the Bay of Bengal part of the Indian Ocean. At 16 UTC on 15 November 2007, the system crossed Bangladesh coast near at long. 89.8 °E. In the present study, two state-of-the-art mesoscale models, MM5 and WRF, have been used to simulate the structure and track of TC Sidr. Horizontal resolution of 90 km and 30 km respectively for mother and nested domain were used in both the models. Various meteorological fields’ viz. central pressure, winds, vorticity, temperature anomaly etc. obtained from the simulations are verified against those observed to test their performance. The simulated tracks are also compared with those obtained from JTWC. The results indicate that MM5 model has better forecast skill in terms of intensity prediction but WRF model has better forecast skill in terms of track prediction of the cyclonic storm.

scholarly journals The Efficacy of the WRF-ARW Model in the Genesis and Intensity Forecast of Tropical Cyclone Fani over the Bay of Bengal

2022 ◽  
Vol 12 (3) ◽  
pp. 85-100
Author(s):  
Md Shakil Hossain ◽  
Md Abdus Samad ◽  
SM Arif Hossen ◽  
SM Quamrul Hassan ◽  
MAK Malliak
Keyword(s):  
Tropical Cyclone ◽  
Bay Of Bengal ◽  
Lead Time ◽  
Wrf Model ◽  
Horizontal Resolution ◽  
Outcome Analysis ◽  
Time Model ◽  
Cyclonic Storm ◽  
Arw Model ◽  
Global Data Assimilation System

An attempt has been carried out to assess the efficacy of the Weather Research and Forecasting (WRF) model in predicting the genesis and intensification events of Very Severe Cyclonic Storm (VSCS) Fani (26 April – 04 May 2019) over the Bay of Bengal (BoB). WRF model has been conducted on a single domain of 10 km horizontal resolution using the Global Data Assimilation System (GDAS) FNL (final) data (0.250 × 0.250). According to the model simulated outcome analysis, the model is capable of predicting the Minimum Sea Level Pressure (MSLP) and Maximum Sustainable Wind Speed (MSWS) pattern reasonably well, despite some deviations. The model has forecasted the Lowest Central Pressure (LCP) of 919 hPa and the MSWS of 70 ms-1 based on 0000 UTC of 26 April. Except for the model run based on 0000 UTC of 26 April, the simulated values of LCP are relatively higher than the observations. According to the statistical analysis, MSLP and MSWS at 850 hPa level demonstrate a significantly greater influence on Tropical Cyclone (TC) formation and intensification process than any other parameters. The model can predict the intensity features well enough, despite some uncertainty regarding the proper lead time of the model run. Reduced lead time model run, particularly 24 to 48 hr, can be chosen to forecast the genesis and intensification events of TC with minimum uncertainty. Journal of Engineering Science 12(3), 2021, 85-100

Fog forecasting for Schiphol airport at sub-kilometre scale.  

2021 ◽  
Author(s):  
Gert-Jan Steeneveld ◽  
Roosmarijn Knol
Keyword(s):  
Spatial Resolution ◽  
Numerical Models ◽  
Wrf Model ◽  
Horizontal Resolution ◽  
Physical Processes ◽  
Radiation Fog ◽  
Fog Forecasting ◽  
Elevation Data ◽  
The Individual ◽  
The Impact

<p>Fog is a critical weather phenomenon for safety and operations in aviation. Unfortunately, the forecasting of radiation fog remains challenging due to the numerous physical processes that play a role and their complex interactions, in addition to the vertical and horizontal resolution of the numerical models. In this study we evaluate the performance of the Weather Research and Forecasting (WRF) model for a radiation fog event at Schiphol Amsterdam Airport (The Netherlands) and further develop the model towards a 100 m grid spacing. Hence we introduce high resolution land use and land elevation data. In addition we study the role of gravitational droplet settling, advection of TKE, top-down diffusion caused by strong radiative cooling at the fog top. Finally the impact of heat released by the terminal areas on the fog formation is studied. The model outcomes are evaluated against 1-min weather observations near multiple runways at the airport.</p><p>Overall we find the WRF model shows an reasonable timing of the fog onset and is well able to reproduce the visibility and meteorological conditions as observed during the case study. The model appears to be relatively insensitive to the activation of the individual physical processes. An increased spatial resolution to 100 m generally results in a better timing of the fog onset differences up to three hours, though not for all runways. The effect of the refined landuse dominates over the effect of refined elevation data. The modelled fog dissipation systematically occurs 3-4 h hours too early, regardless of physical processes or spatial resolution. Finally, the introduction of heat from terminal buildings delays the fog onset with a maximum of two hours, an overestimated visibility of 100-200 m and a decrease of the LWC with 0.10-0.15 g/kg compared to the reference.</p>

scholarly journals Simulation of Intensity, Track and Landfall of Tropical Cyclonic Storm Roanu over the Bay of Bengal Using WRF-ARW Model

2021 ◽  
Vol 10 (1) ◽  
pp. 33-45
Author(s):  
Ariful Alam ◽  
Shammy Ahmed ◽  
Sharmin Rahman ◽  
Umme Habiba ◽  
Muhammad Abul Kalam Mallik ◽  
...  
Keyword(s):  
Bay Of Bengal ◽  
Wrf Model ◽  
Short Wave ◽  
Horizontal Resolution ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Microphysics Scheme ◽  
Cyclonic Storm ◽  
Position Errors ◽  
Hourly Data

Almost every year, tropical cyclone forms over the Bay of Bengal in pre-monsoon and post-monsoon which strikes Bangladesh coast and the east coast of India. As the full thermodynamic features of a cyclone is not solved yet, an attempt has been made to simulate the track and landfall of cyclonic disturbances over the Bay of Bengal by using Weather Research and Forecasting (WRF) model. The WRF model (version 3.8) was run in a single domain of 20 km horizontal resolution. The model was run using WRF Single-Moment 3- class microphysics scheme, Kain- Fritsch (new Eta) cumulus physics scheme, Yonsei University planetary boundary layer scheme, revised MM5 surface layer physics scheme, Rapid Radiative Transfer Model (RRTM) for long-wave and Dudhia scheme for short-wave scheme. The model was run for 24-h, 48-h, 72-h and 96-h using the National Centre for Environmental Prediction (NCEP) high-resolution Global Final (FNL) Analysis 6-hourly data using initial and lateral boundary conditions. The model simulated landfall position errors are found 53 km, 129 km, 119km and 23 km and time errors are found 02 E, 06 D, 02 E and 00 for 96-h, 72-h, 48-h and 24-h model run respectively (E indicates Earlier and D indicates Delay). The minimum time and position error is found in 24-hrs simulation. The spatial distribution is captured by the model is almost appropriate but the computational station rainfall is found less than that of observed rainfall. The Dhaka University Journal of Earth and Environmental Sciences, Vol. 10(1), 2021, P 33-45

Simulation of the Downshear Reformation of a Tropical Cyclone

2015 ◽  
Vol 72 (12) ◽  
pp. 4529-4551 ◽  
Author(s):  
Leon T. Nguyen ◽  
John Molinari
Keyword(s):  
Boundary Layer ◽  
Tropical Cyclone ◽  
Diabatic Heating ◽  
Wrf Model ◽  
Relative Vorticity ◽  
Horizontal Resolution ◽  
Cyclonic Circulation ◽  
Tropical Storm ◽  
Weather Research And Forecasting ◽  
Cyclonic Vorticity

Abstract The downshear reformation of Tropical Storm Gabrielle (2001) was simulated at 1-km horizontal resolution using the Weather Research and Forecasting (WRF) Model. The environmental shear tilted the initial parent vortex downshear left and forced azimuthal wavenumber-1 kinematic, thermodynamic, and convective asymmetries. The combination of surface enthalpy fluxes and a lack of penetrative downdrafts right of shear allowed boundary layer moist entropy to increase to a maximum downshear right. This contributed to convective instability that fueled the downshear convection. Within this convection, an intense mesovortex rapidly developed, with maximum boundary layer relative vorticity reaching 2.2 × 10−2 s−1. Extreme vortex stretching played a key role in the boundary layer spinup of the mesovortex. Cyclonic vorticity remained maximized in the boundary layer and intensified upward with the growth of the convective plume. The circulation associated with the mesovortex and adjacent localized cyclonic vorticity anomalies comprised a developing “inner vortex” on the downshear-left (downtilt) periphery of the parent cyclonic circulation. The inner vortex was nearly upright within a parent vortex that was tilted significantly with height. This inner vortex became the dominant vortex of the system, advecting and absorbing the broad, tilted parent vortex. The reduction of tropical cyclone (TC) vortex tilt from 65 to 20 km in 3 h reflected the emerging dominance of this upright inner vortex. The authors hypothesize that downshear reformation, resulting from diabatic heating associated with asymmetric convection, can aid the TC’s resistance to shear by reducing vortex tilt and by enabling more diabatic heating to occur near the center, a region known to favor TC intensification.

scholarly journals Impacts of Topsoil and Surface Water Salinity on Agriculture: A Study at Paikgachha, Khulna

2021 ◽  
Vol 8 (2) ◽  
pp. 25-32
Author(s):  
Md Ferdous ur Rahman Bhuiya ◽  
Md Humayun Kabir ◽  
Muhammad Ferdaus
Keyword(s):  
Tropical Cyclone ◽  
West Bengal ◽  
Small Deviation ◽  
Wrf Model ◽  
India Meteorological Department ◽  
Horizontal Resolution ◽  
Weather Research And Forecasting ◽  
Sea Level Pressure ◽  
Surface Water Salinity ◽  
Maximum Sustained Wind Speed

Studying the structure, intensity and track of tropical cyclone is very important in effective tropical cyclone warning. In this study, an attempt has been made to simulate the Super Cyclone Amphan to reproduce the structure, intensity and track of the storm that occurred over the Bay of Bengal and made landfall over the coastal zone of Sundarban between Western Bangladesh and Eastern West Bengal of India on 20 May 2020. The Weather Research and Forecasting (WRF) Model was run 120 hours from 0000 UTC of 16 May to 0000 UTC of 21 May 2021 with 9 km horizontal resolution to simulate the selected storm. The model simulated intensity and track of the storm were compared with that of best track data of India Meteorological Department (IMD). The results obtained from the WRF model indicated that the intensity of the selected cyclone in terms of Mean Sea Level Pressure (MSLP) and Maximum Sustained Wind speed (MSW) were 905 hPa and 243 kph whereas the observed MSLP and MSW were close to 920 hPa and 241 kph respectively. It was also indicated that the model predicted the track of the cyclone reasonably well and it was quite close to the best track data throughout its path till landfall with very small deviation and the cyclone made landfall at 7-8 hours before the actual landfall with 167.4 km position error. The Dhaka University Journal of Earth and Environmental Sciences, Vol. 8(2), 2019, P 25-32

scholarly journals High-Resolution Tropical Channel Model Simulations of Tropical Cyclone Climatology and Intraseasonal-to-Interannual Variability

2019 ◽  
Vol 32 (22) ◽  
pp. 7871-7895 ◽  
Author(s):  
Dan Fu ◽  
Ping Chang ◽  
Christina M. Patricola ◽  
R. Saravanan
Keyword(s):  
Tropical Cyclone ◽  
North Pacific ◽  
Large Scale ◽  
Channel Model ◽  
Southern Oscillation ◽  
Wrf Model ◽  
Seasonal Prediction ◽  
Horizontal Resolution ◽  
North Indian Ocean ◽  
Channel Configuration

Abstract We tailored a tropical channel configuration of the Weather Research and Forecasting (WRF) Model to study tropical cyclone (TC) activity and associated climate variabilities. This tropical channel model (TCM) covers from 30°S to 50°N at 27-km horizontal resolution, with physics parameterizations carefully selected to achieve more realistic simulations of TCs and large-scale climate mean states. We performed 15-member ensembles of retrospective simulations from 1982 to 2016 hurricane seasons. A thorough comparison with observations demonstrates that the TCM yields significant skills in simulating TC activity climatology and variabilities in each basin, as well as TC physical structures. The correlation of the ensemble averaged accumulated cyclone energy (ACE) with observations in the western North Pacific (WNP), eastern North Pacific (ENP), and North Atlantic (NAT) is 0.80, 0.64, and 0.61, respectively, but is insignificant in the north Indian Ocean (NIO). Moreover, the TCM-simulated modulations of El Niño–Southern Oscillation (ENSO) and the Madden–Julian oscillation (MJO) on the large-scale environment and TC genesis also agree well with observations. To examine the TCM’s potential for seasonal TC prediction, the model is used to forecast the 2017 and 2018 hurricane seasons, using bias-corrected sea surface temperatures (SSTs) from the CFSv2 seasonal prediction results. The TCM accurately predicts the hyperactive 2017 NAT hurricane season and near-normal WNP and ENP hurricane seasons when initialized in May. In addition, the TCM accurately predicts TC activity in the NAT and WNP during the 2018 season, but underpredicts ENP TC activity, in association with a poor ENSO forecast.

scholarly journals Impact of microphysics parameterization schemes in simulation of vardah cyclone using the advanced mesoscale weather research and forecasting model

2018 ◽  
Vol 7 (3.29) ◽  
pp. 272 ◽  
Author(s):  
P Janardhan Saikumar ◽  
T Ramashri
Keyword(s):  
Tropical Cyclone ◽  
Weather Prediction ◽  
Wrf Model ◽  
Numerical Weather Prediction Model ◽  
Horizontal Resolution ◽  
Cyclone Track ◽  
Microphysics Scheme ◽  
Parameterization Schemes ◽  
Single Moment ◽  
Indian Meteorological Department

The very severe Tropical Cyclone Vardah caused huge damage to property and life in south India during December 2016. The sensitivity of numerical simulations of the very severe tropical cyclone Vardah to different physics parameterization schemes is carried out to determine the best microphysics and cumulus physics parameterization schemes. The WRF Numerical weather prediction model configured with two nested domains. The horizontal resolution of domain-1is 27 km and domain-2 is 9 km. The tropical cyclone Vardah simulated track results were compared with the best track data given by the Indian Meteorological Department (IMD). WRF model Simulations were carried out using different microphysics (mp) parameterization schemes by fixing convective cumulus physics (cu) option to Grell-3D ensemble scheme and boundary layer option to updated Yonsei University scheme. The Vardah Cyclone track well simulated using WRF Single Moment-3 (WSM3) microphysics scheme in combination with G3D cumulus physics scheme. The cumulus physics and microphysics parameterization schemes influence the cyclone track prediction skill.  

scholarly journals Track and Landfall Characteristics of Very Severe Cyclonic Storm Fani over the Bay of Bengal using WRF Model

2021 ◽  
Vol 69 (2) ◽  
pp. 101-108
Author(s):  
Md Shakil Hossain ◽  
Md Abdus Samad ◽  
Most Razia Sultana ◽  
MAK Mallik ◽  
Md Joshem Uddin
Keyword(s):  
Bay Of Bengal ◽  
Model Simulation ◽  
Wrf Model ◽  
India Meteorological Department ◽  
Horizontal Resolution ◽  
Weather Research And Forecasting ◽  
Cyclonic Storm ◽  
Intensity Forecast ◽  
Global Data Assimilation System ◽  
Future Events

An attempt has been made to assess the capability of the Weather Research and Forecasting (WRF) model in simulating the track and landfall characteristics of Tropical Cyclone (TC) Fani (25th April – 05th May 2019) over the Bay of Bengal (BoB). WRF model has conducted on a single domain of 10 km horizontal resolution using Global Data Assimilation System (GDAS) data (0.250×0.250). The model predicted outcomes show auspicious agreement with the observed datasets of the Bangladesh Meteorological Department (BMD) and India Meteorological Department (IMD). It is found that the diminished lead time of the model run plays a crucial role in delivering good consistency with the minimum forecast uncertainty. A strong correlation between the track and intensity forecast deviations has also been determined. According to the results, the model simulation which captures the minimum deviation in the intensity forecast also ensures better track prediction of the system. The feasibility of the track and landfall forecast by the model even up to 27 hr advance is reasonably well. Finally, it can be decided that the model is capable to predict the cyclonic storm Fani precisely and it can be chosen confidently for future events over the BoB. Dhaka Univ. J. Sci. 69(2): 101-108, 2021 (July)

scholarly journals Sensitivity of Simulated Tropical Cyclone Structure and Intensity to Horizontal Resolution

2010 ◽  
Vol 138 (3) ◽  
pp. 688-704 ◽  
Author(s):  
Megan S. Gentry ◽  
Gary M. Lackmann
Keyword(s):  
Tropical Cyclone ◽  
Wrf Model ◽  
Domain Size ◽  
Horizontal Resolution ◽  
Weather Research And Forecasting ◽  
Grid Spacing ◽  
Physical Processes ◽  
Hurricane Ivan ◽  
Horizontal Grid ◽  
Grid Length

Abstract The Weather Research and Forecasting (WRF) model is used to test the sensitivity of simulations of Hurricane Ivan (2004) to changes in horizontal grid spacing for grid lengths from 8 to 1 km. As resolution is increased, minimum central pressure decreases significantly (by 30 hPa from 8- to 1-km grid spacing), although this increase in intensity is not uniform across similar reductions in grid spacing, even when pressure fields are interpolated to a common grid. This implies that the additional strengthening of the simulated tropical cyclone (TC) at higher resolution is not attributable to sampling, but is due to changes in the representation of physical processes important to TC intensity. The most apparent changes in simulated TC structure with resolution occur near a grid length of 4 km. At 4-km grid spacing and below, polygonal eyewall segments appear, suggestive of breaking vortex Rossby waves. With sub-4-km grid lengths, localized, intense updraft cores within the eyewall are numerous and both polygonal and circular eyewall shapes appear regularly. Higher-resolution simulations produce a greater variety of shapes, transitioning more frequently between polygonal and circular eyewalls relative to lower-resolution simulations. It is hypothesized that this is because of the ability to resolve a greater range of wavenumbers in high-resolution simulations. Also, as resolution is increased, a broader range of updraft and downdraft velocities is present in the eyewall. These results suggest that grid spacing of 2 km or less is needed for representation of important physical processes in the TC eyewall. Grid-length and domain size suggestions for operational prediction are provided; for operational prediction, a grid length of 3 km or less is recommended.

scholarly journals Sensitivity of different physics schemes using WRF model in Typhoon Damrey (2017) over the Indochina region

2021 ◽  
Vol 2145 (1) ◽  
pp. 012046
Author(s):  
Kulaya Keawsang-In ◽  
Sujittra Ratjiranukool ◽  
Pakpoom Ratjiranukool
Keyword(s):  
Tropical Cyclone ◽  
Flash Flood ◽  
Wrf Model ◽  
Final Analysis ◽  
Heavy Precipitation ◽  
Horizontal Resolution ◽  
Cumulus Parameterization ◽  
Japan Meteorological Agency ◽  
Strong Wind ◽  
Typhoon Damrey

Abstract To reduce the tropical cyclone impact of lives and economics, the precise forecast of the event is required. The typhoon Damrey (2017), which caused ravaging of the strong wind, heavy precipitation, flash flood and storm surge over the Indochina region, was simulated by Weather Research and forecasting (WRF) model. The simulated duration was 8 days starting from 31 October 2017 00 00 UTC to 8 November 2017 00 00 UTC. The NCEP 6-hour global FNL (final analysis) data at 1-degree resolution is provided for initial condition. The WRF model was run in a single domain of 20 km horizontal resolution bounded 0 to 20 N and 96°E to 124°E. The different physics schemes, which are the microphysics schemes, the planetary boundary layer schemes and cumulus parameterization schemes, were emphasized to examine the suitable schemes in tropical cyclone simulation over the Indochina region. To evaluate the reliability of the simulation of tropical cyclone, the track-position is correlated with the Japan Meteorological Agency (JMA) observation. The results show that the typhoon simulation forced by Belts-Millers-Janjic cumulus, WSM6 microphysics was suitable for simulating of typhoon Damrey.

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