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.

scholarly journals Simulation of Thermodynamic Features of a Thunderstorm Event over Dhaka using WRF-ARW Model

2018 ◽  
Vol 37 ◽  
pp. 131-145
Author(s):  
Md Mijanur Rahman ◽  
Md Abdus Samad ◽  
SM Quamrul Hassan
Keyword(s):  
Convective Available Potential Energy ◽  
Model Performance ◽  
Vertical Wind Shear ◽  
Longwave Radiation ◽  
Final Analysis ◽  
Horizontal Resolution ◽  
Cumulus Parameterization ◽  
Shortwave Radiation ◽  
Radiative Transfer Model ◽  
Transfer Model

An attempt has been made to simulate the thermodynamic features of the thunderstorm (TS) event over Dhaka (23.81°N, 90.41°E) occurred from 1300 UTC to 1320 UTC of 4 April 2015 using Advanced Research dynamics solver of Weather Research and Forecasting model (WRF-ARW). The model was run to conduct a simulation for 48 hours on a single domain of 5 km horizontal resolution utilizing six hourly Global Final Analysis (FNL) datasets from 0600 UTC of 3 April 2015 to 0600 UTC of 5 April 2015 as initial and lateral boundary conditions. Kessler schemes for microphysics, Yonsei University (YSU) scheme for planetary boundary layer (PBL) parametrization, Revised MM5 scheme for surface layer physics, Rapid Radiative Transfer Model (RRTM) for longwave radiation, Dudhia scheme for shortwave radiation and Kain–Fritsch (KF) scheme for cumulus parameterization were used. Hourly outputs produced by the model have been analyzed numerically and graphically using Grid Analysis and Display System (GrADS). Deep analyses were carried out by examining several thermodynamic parameters such as mean sea level pressure (MSLP), wind pattern, vertical wind shear, vorticity, temperature, convective available potential energy (CAPE), relative humidity (RH) and rainfall. To validate the model performance, simulated values of MSLP, maximum and minimum temperature and RH were compared with observational data obtained from Bangladesh Meteorological Department (BMD). Rainfall values were compared with that of BMD and Tropical Rainfall Measuring Mission (TRMM) of National Aeronautics and Space Administration (NASA). Based on the comparisons and validations, the present study advocates that the model captured the TS event reasonably well.GANIT J. Bangladesh Math. Soc.Vol. 37 (2017) 131-145

scholarly journals Simulation of the Summer Monsoon Rainfall over East Asia Using the NCEP GFS Cumulus Parameterization at Different Horizontal Resolutions

2014 ◽  
Vol 29 (5) ◽  
pp. 1143-1154 ◽  
Author(s):  
Kyo-Sun Sunny Lim ◽  
Song-You Hong ◽  
Jin-Ho Yoon ◽  
Jongil Han
Keyword(s):  
Summer Monsoon ◽  
Monsoon Rainfall ◽  
Asian Summer Monsoon ◽  
Monsoon Season ◽  
Wrf Model ◽  
Horizontal Resolution ◽  
Cumulus Parameterization ◽  
Grid Spacing ◽  
Simulated Precipitation ◽  
Horizontal Grid

Abstract The most recent version of the simplified Arakawa–Schubert (SAS) cumulus scheme in the National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS) (GFS SAS) is implemented in the Weather Research and Forecasting (WRF) Model with a modification of the triggering condition and the convective mass flux in order to make it dependent on the model’s horizontal grid spacing. The East Asian summer monsoon season of 2006 is selected in order to evaluate the performance of the modified GFS SAS scheme. In comparison to the original GFS SAS scheme, the modified GFS SAS scheme shows overall better agreement with the observations in terms of the simulated monsoon rainfall. The simulated precipitation from the original GFS SAS scheme is insensitive to the model’s horizontal grid spacing, which is counterintuitive because the portion of the resolved clouds in a grid box should increase as the model grid spacing decreases. This behavior of the original GFS SAS scheme is alleviated by the modified GFS SAS scheme. In addition, three different cumulus schemes (Grell and Freitas, Kain and Fritsch, and Betts–Miller–Janjić) are chosen to investigate the role of a horizontal resolution on the simulated monsoon rainfall. Although the forecast skill of the surface rainfall does not always improve as the spatial resolution increases, the improvement of the probability density function of the rain rate with the smaller grid spacing is robust regardless of the cumulus parameterization scheme.

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

scholarly journals Simulation of Structure, Track and Landfall of Tropical Cyclone Bijli Using WRF-ARW Model

2015 ◽  
Vol 39 (2) ◽  
pp. 157-167 ◽  
Author(s):  
KM Zahir Rayhun ◽  
DA Quadir ◽  
MA Mannan Chowdhury ◽  
MN Ahasan ◽  
MS Haque
Keyword(s):  
Tropical Cyclone ◽  
Tropical Cyclones ◽  
Convective Available Potential Energy ◽  
Wrf Model ◽  
Relative Vorticity ◽  
Cumulus Parameterization ◽  
Arw Model ◽  
Boundary Layer Scheme ◽  
Cumulus Parameterization Schemes ◽  
Academy Of Sciences

An attempt was made to simulate the structure, track, landfall and a few dynamical aspects of the tropical cyclone Bijli that formed over the Bay of Bengal using WRF-ARW model. WRF model was run in a single domain using KF cumulus parameterization schemes with WSM 3 micro physics and YSU planetary boundary layer scheme. The ARW model was run for 24, 48, 72 and 96 hrs to simulate structure, track and landfall of tropical cyclones Bijli. The different simulated parameters viz. minimum sea level pressure, maximum wind speed, convective available potential energy and relative vorticity have been studied. The results showed that the model is capable to forecast the formation of the first depression 60 - 78 hrs in advance. This indicates the high and unique predictive power of ARW model for predicting the tropical cyclone formation. The model generates a realistic structure of the tropical cyclones with high spatial details. This was possible due to the higher spatial resolution of the regional model. One of the outstanding findings of the study is that the model was successfully predicted the tracks, recurvature and probable areas and time of landfall of the selected tropical cyclone Bijli with high accuracy even in the 96 hrs predictions.Journal of Bangladesh Academy of Sciences, Vol. 39, No. 2, 157-167, 2015

scholarly journals Analysis of WRF Simulation Skill for Seasonal Rainfall: A Case Study of 2015 September–November Season

2019 ◽  
Author(s):  
Ronald Ingula Odongo ◽  
Isaac Mugume
Keyword(s):  
Wrf Model ◽  
Final Analysis ◽  
Horizontal Resolution ◽  
Weather Research And Forecasting ◽  
Entire Study ◽  
Seasonal Characteristics ◽  
Rain Season ◽  
Environmental Prediction ◽  
Wet Spells ◽  
Weather Research

Rainfall is a major climate parameter whose variation in space and time influences activities in different weather sensitive sectors such as agriculture, transport, and energy among others. Therefore, accurately forecasting rainfall is of paramount importance to the development of these sectors. In this regard, this study sought to contribute to quantitative forecasting of rainfall over Eastern Uganda through assessing the Weather Research and Forecasting model’s ability to simulate the intra–seasonal characteristics of the September to December rain season. These were: onset and cessation dates; wet days and lengths of the wet spells. The data used in the study included daily ground rainfall observations and lateral and boundary conditions data from the National Centers for Environmental Prediction (NCEP) final analysis at 1 0 horizontal resolution and at a temporal resolution of 6 hours for the entire study period were used to initialize the Weather Research and Forecasting (WRF) model. The study considered four weather synoptic weather stations namely; Jinja, Serere, Soroti and Tororo. The results show that the WRF model generally simulated fewer wet days at each station except for Tororo. Also, the WRF model simulated earlier onset and cessation dates of the rainfall season and overestimated the length of the wet spells.

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 Regional Simulation of Indian summer Monsoon Intraseasonal Oscillations at Gray Zone Resolution

2017 ◽  
Author(s):  
Xingchao Chen ◽  
Olivier M. Pauluis ◽  
Fuqing Zhang
Keyword(s):  
Summer Monsoon ◽  
Indian Summer Monsoon ◽  
Monsoon Rainfall ◽  
Deep Convection ◽  
Wrf Model ◽  
Central India ◽  
Horizontal Resolution ◽  
Cumulus Parameterization ◽  
Gray Zone ◽  
Intraseasonal Oscillations

Abstract. Simulations of the Indian summer monsoon by cloud-permitting WRF model at gray zone resolution are described in this study, with a particular emphasis on the model ability to capture the Monsoon Intraseasonal Oscillations (MISO). Five boreal summers are simulated from 2007 to 2011 using the ERA-Interim reanalysis as lateral boundary forcing data. Our experimental set-up relies on a high horizontal resolution of 9 km to capture deep convection without the use of a cumulus parameterization. When compared to simulations with coarser grid spacing (27-km) and using the cumulus scheme, our approach results in a reduction of the biases in mean precipitation and in more realistic reproduction of the low frequency variability associated with MISO. Results show that the model at gray zone resolution captures the fundamental features of the summer monsoon. The spatial distributions and temporal evolutions of monsoon rainfall in WRF simulations are verified qualitatively well against observations from the Tropical Rainfall Measurement Mission (TRMM), with regional maxima located over West Ghats, central India, Himalaya foothills and the west coast of Myanmar. The onset, breaks and withdrawal of the summer monsoon in each year are also realistically captured by the model. MISO phase composites of monsoon rainfall, low-level wind and precipitable water anomalies in the simulations are compared qualitatively with the observations. Both the simulations and observations show a northeastward propagation of the MISO, with the intensification and weakening of Somali Jet over the Arabian Sea during the active and break phases of the Indian summer monsoon.

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 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 Flash-flood forecasting in two Spanish Mediterranean catchments: a comparison of distinct hydrometeorological ensemble prediction strategies

2017 ◽  
Author(s):  
Beatrice Vincendon ◽  
Arnau Amengual
Keyword(s):  
Flash Flood ◽  
Forecast Error ◽  
Wrf Model ◽  
Heavy Precipitation ◽  
Flood Forecasting ◽  
Optimal Number ◽  
Scale Model ◽  
Ensemble Prediction ◽  
Small Scale ◽  
Flash Flood Forecasting

Abstract. Hydrological Ensemble Prediction Systems (HEPSs) are becoming more and more popular methods to deal with the meteorological and hydrological uncertainties that affect discharge forecasts. These uncertainties are particularly difficult to handle when dealing with Mediterranean flash-flood forecasting as many hydrological and meteorological factors take place and precipitation comes from small scale convective systems. In this work, the performances of distinct HEPS are compared for two heavy precipitation events that affected two different semi-arid Spanish Mediterranean catchments: the cases of the 03 November 2011 on the Llobregat River in Catalonia, and the 28 September 2012 on the Guadalentín River near in Murcia. The latter case corresponds to the IOP8 of HYMEX field campaign. The uncertainty on quantitative precipitation forecasting is sampled by using two different meteorological ensemble generation strategies. First, a convection-permitting EPS, which consists in dynamically downscaling the ECMWF-EPS directly by means of the WRF model. The second EPS strategy is based on the AROME-WMED convective-scale model. Its deterministic QPFs are perturbed based on a previous rainfall forecast error climatology and by using the probability density functions of the errors, in term of total amounts and location of the heaviest rainfalls. The population of both ensembles is of 50 members, which are used to drive the HEC-HMS and ISBA-TOP hydrological models. For each HEPS, the performance is assessed in term of the quantitative discharge forecasts. The results point out the benefits of using (i) a hydrological model when evaluating highly-variable and convective-driven precipitation fields and (ii) an EPS to better encompass these uncertainties arising from different level of the HEPS. Issues about the optimal number of ensemble members and impact of the ensemble forecasting lead time are addressed for optimal flash-flood forecasting purposes as well.

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