scholarly journals Study of tropical cyclone "Fanoos" using MM5 model – a case study

2009 ◽  
Vol 9 (1) ◽  
pp. 43-51 ◽  
Author(s):  
S. Ramalingeswara Rao ◽  
K. Muni Krishna ◽  
O. S. R. U. Bhanu Kumar
Keyword(s):  
Tropical Cyclone ◽  
East Coast ◽  
Mesoscale Model ◽  
India Meteorological Department ◽  
Cumulus Parameterization ◽  
Cumulus Parameterization Scheme ◽  
Sea Level Pressure ◽  
Mm5 Model ◽  
Made In

Abstract. Tropical cyclones are one of the most intense weather hazards over east coast of India and create a lot of devastation through gale winds and torrential floods while they cross the coast. So an attempt is made in this study to simulate track and intensity of tropical cyclone "Fanoos", which is formed over the Bay of Bengal during 5–10 December 2005 by using mesoscale model MM5. The simulated results are compared with the observed results of India Meteorological Department (IMD); results show that the cumulus parameterization scheme, Kain-Fritsch (KF) is more accurately simulated both in track and intensity than the other Betts-Miller (BM) and Grell Schemes. The reason for better performance of KF-1 scheme may be due to inclusion of updrafts and downdrafts. The model could predict the minimum Central Sea Level Pressure (CSLP) as 983 hPa as compared to the IMD reports of 984 hPa and the wind speed is simulated at maximum 63 m/s compared to the IMD estimates of 65 m/s. Secondly "Fanoos" development from the lagrangian stand point in terms of vertical distribution of Potential Vorticity (PV) is also carried out around cyclone centre.

scholarly journals The evaluation of Kain-Fritsch scheme in tropical cyclone simulation

MAUSAM ◽  
2021 ◽  
Vol 57 (3) ◽  
pp. 395-410
Author(s):  
K. SATHI DEVI ◽  
D. HARI PRASAD ◽  
D. V. BHASKAR RAO
Keyword(s):  
Tropical Cyclone ◽  
Sea Level ◽  
Model Simulation ◽  
Analysis Data ◽  
Cumulus Parameterization ◽  
Cumulus Parameterization Scheme ◽  
Sea Level Pressure ◽  
Maximum Rainfall ◽  
Warm Core ◽  
Super Cyclone

lkj & bl v/;;u esa 25&30 vDrwcj 1999 rd dh vof/k esa mM+hlk esa vk, egkpØokrksa ds ewY;kadu dk izfr:i.k djus ds fy, dSu fÝ’k ds diklh izkpyhdj.k ;kstuk ds lkFk ,u- lh- ,- vkj-  ,e- ,e- 5 dk mi;ksx fd;k x;k gSA 25 vDrwcj 1999 ds 0000 ;w Vh lh ij 90] 30 vkSj 10 fd-eh- ds f}iFkh vk/kkfjr {kSfrt iz{ks=ksa ¼Mksesu½ okys ,u- lh- ,- vkj-  ,e- ,e- 5 dks 5 fnu dh vof/k ds fy, lesfdr fd;k x;k gSA bl v/;;u ds fy, izkjfEHkd vkSj ifjlhek dh fLFkfr;ksa dks ,d va’k ds varjky ij miyC/k gq, ,u- lh- bZ- ih-  ,Q- ,u- ,y- fo’ys"k.k vk¡dM+ksa ls fy;k x;k gSA             ;g izfr:fir fun’kZ 954 gSDVkikLdy ij izkIr fd, x, leqnz ry ds e/; nkc vkSj 58 feuV izfr lSdaM dh vf/kdre iouksa ds lkFk mM+hlk esa vk, egkpØokr dh fodklkRed fLFkfr;ksa dks izLrqr djrk gSA bl fun’kZ ls vfuok;Z vfHky{k.kksa uker% m".k ØksM] dsanz vkSj dsanz fHkfRr izfr:i.k] gjhdsu ØksM iouksa dks izkIr fd;k x;k gSA ;g fun’kZ pØokr ds LFky Hkkx esa izos’k djus ds mijkar ml LFky ds fudV 40 ls-eh- izfrfnu dh vf/kdre o"kkZ dk iwokZuqeku yxk ldrk gS A ;g fun’kZ 24 ?kaVksa es 120 fd-eh- =qfV;ksa vkSj 120 ?kaVksa esa 0 fd-eh- dh deh ds lkFk egkpØokr ds iFk dk ,dne lgh vkdyu izLrqr djrk gSA In this study NCAR MM5 with the cumulus parameterization scheme of Kain-Fritsch is used to simulate the evaluation of Orissa Super Cyclone for the period 25-30 October 1999. The NCAR MM5 with two-way nested horizontal domains of 90, 30 and 10 km are integrated for five days starting from 0000 UTC of 25 October, 1999. The initial and boundary conditions for this study have been taken from NCEP FNL analysis data available at 1° resolution. The model simulation produces the development of the Orissa Super Cyclone with attained central sea level pressure of 954 hPa and maximum wind of 58 msec-1. The essential characteristics such as warm core, eye and eye-wall simulation, hurricane core winds were obtained by the model. The model could predict a maximum rainfall of 40 cm/day near the landfall point. The model produces a very good estimate of track with errors of 120 km at 24 hours and decreasing to 0 km at 120 hours.  

scholarly journals The Application of Barnes Filter to Positioning the Center of Landed Tropical Cyclone in Numerical Models

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Haibo Zou ◽  
Shanshan Wu ◽  
Xueting Yi ◽  
Nan Wu
Keyword(s):  
Numerical Model ◽  
Tropical Cyclone ◽  
Sea Level ◽  
Numerical Models ◽  
Small Scale ◽  
Model Output ◽  
Sea Level Pressure ◽  
Level Pressure ◽  
Distance Difference

After a tropical cyclone (TC) making landfall, the numerical model output sea level pressure (SLP) presents many small-scale perturbations which significantly influence the positioning of the TC center. To fix the problem, Barnes filter with weighting parameters C=2500 and G=0.35 is used to remove these perturbations. A case study of TC Fung-Wong which landed China in 2008 shows that Barnes filter not only cleanly removes these perturbations, but also well preserves the TC signals. Meanwhile, the centers (track) obtained from SLP processed with Barnes filter are much closer to the observations than that from SLP without Barnes filter. Based on the distance difference (DD) between the TC center determined by SLP with/without Barnes filter and observation, statistics analysis of 12 TCs which landed China during 2005–2015 shows that in most cases (about 85%) the DDs are small (between −30 km and 30 km), while in a few cases (about 15%) the DDs are large (greater than 30 km even 70 km). This further verifies that the TC centers identified from SLP with Barnes filter are more accurate compared to that directly obtained from model output SLP. Moreover, the TC track identified with Barnes filter is much smoother than that without Barnes filter.

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 SENSITIVITY TEST OF PARAMETERIZATION SCHEMES OF MM5 MODEL FOR PREDICTION OF THE HIGH IMPACT RAINFALL EVENTS OVER BANGLADESH

2014 ◽  
Vol 44 (1) ◽  
pp. 33-42 ◽  
Author(s):  
M.N. Ahasan ◽  
M. A. M. Chowdhury ◽  
D.A. Quadir
Keyword(s):  
Summer Monsoon ◽  
Mesoscale Model ◽  
Tropical Rainfall Measuring Mission ◽  
High Impact ◽  
Sensitivity Test ◽  
Cumulus Parameterization ◽  
Parameterization Schemes ◽  
Mm5 Model ◽  
Medium Range Forecast ◽  
Cumulus Parameterization Schemes

The sensitivity test of parameterization schemes for prediction of summer monsoon high impact rainfallevents (HIRE) over Bangladesh has been performed using the Fifth-Generation PSU/NCAR Mesoscale Model(MM5) conducting six historical HIRE cases. The MM5 model was run on triple-nested domains at 45, 15, 5 kmhorizontal resolutions using Anthes-Kuo (AK), Grell (Gr), Kain-Fritsch (KF), Betts-Miller (BM) andKain-Fritsch2 (KF2) cumulus parameterization schemes (CPS) with Medium Range Forecast (MRF) andBlackadar planetary boundary layer (PBL).The model predicted rainfall was compared both spatially andquantitatively with Tropical Rainfall Measuring Mission (TRMM) rainfall. While parameterization options ofMM5 model have been investigated spatially for Bangladesh, Anthes-Kuo CPS with both MRF and BlackadarPBL (AKM & AKB) options of MM5 have found suitable. Quantitatively, Anthes-Kuo CPS with MRF PBL (AKM)option has calculated the better average rainfall over Bangladesh. By this way, AKM has found suitable in bothspatial and quantitaive comparisons. Thus, Anthes-Kuo CPS with MRF PBL (AKM) has considered as the bestMM5 option for prediction of summer monsoon HIRE cases over Bangladesh.The sensitivity test of parameterization schemes for prediction of summer monsoon high impact rainfall events (HIRE) over Bangladesh has been performed using the Fifth-Generation PSU/NCAR Mesoscale Model (MM5) conducting six historical HIRE cases. The MM5 model was run on triple-nested domains at 45, 15, 5 km horizontal resolutions using Anthes-Kuo (AK), Grell (Gr), Kain-Fritsch (KF), Betts-Miller (BM) and Kain-Fritsch2 (KF2) cumulus parameterization schemes (CPS) with Medium Range Forecast (MRF) and Blackadar planetary boundary layer (PBL).The model predicted rainfall was compared both spatially and quantitatively with Tropical Rainfall Measuring Mission (TRMM) rainfall. While parameterization options of MM5 model have been investigated spatially for Bangladesh, Anthes-Kuo CPS with both MRF and Blackadar PBL (AKM & AKB) options of MM5 have found suitable. Quantitatively, Anthes-Kuo CPS with MRF PBL (AKM) option has calculated the better average rainfall over Bangladesh. By this way, AKM has found suitable in both spatial and quantitaive comparisons. Thus, Anthes-Kuo CPS with MRF PBL (AKM) has considered as the best MM5 option for prediction of summer monsoon HIRE cases over Bangladesh. DOI: http://dx.doi.org/10.3329/jme.v44i1.19496

Evaluation of MM5 model resolution when applied to prediction of National Fire Danger Rating indexes

2006 ◽  
Vol 15 (2) ◽  
pp. 147 ◽  
Author(s):  
Jeanne L. Hoadley ◽  
Miriam L. Rorig ◽  
Larry Bradshaw ◽  
Sue A. Ferguson ◽  
Kenneth J. Westrick ◽  
...  
Keyword(s):  
Extreme Event ◽  
Mesoscale Model ◽  
Model Performance ◽  
Fire Danger ◽  
Western Montana ◽  
Fire Season ◽  
Mm5 Model ◽  
Model Predictions ◽  
Northern Idaho

Weather predictions from the MM5 mesoscale model were used to compute gridded predictions of National Fire Danger Rating System (NFDRS) indexes. The model output was applied to a case study of the 2000 fire season in Northern Idaho and Western Montana to simulate an extreme event. To determine the preferred resolution for automating NFDRS predictions, model performance was evaluated at 36, 12, and 4 km. For those indexes evaluated, the best results were consistently obtained for the 4-km domain, whereas the 36-km domain had the largest mean absolute errors. Although model predictions of fire danger indexes are consistently lower than observed, analysis of time series results indicates that the model does well in capturing trends and extreme changes in NFDRS indexes.

scholarly journals The Impact of Cumulus Parameterization Schemes on the Simulation of Tropical Cyclone “Roanu” Over the Bay of Bengal Using WRF Model

2020 ◽  
Vol 68 (1) ◽  
pp. 87-94
Author(s):  
Saifullah ◽  
Md Idris Ali ◽  
Ashik Imran
Keyword(s):  
Tropical Cyclone ◽  
Bay Of Bengal ◽  
Wrf Model ◽  
Absolute Error ◽  
Sensitivity Study ◽  
Cumulus Parameterization ◽  
Weather Research And Forecasting ◽  
Sea Level Pressure ◽  
Cumulus Parameterization Schemes ◽  
The Impact

A sensitivity study has been made on cumulus parameterization (CP) schemes of Weather Research and Forecasting (WRF) model for the simulation of tropical cyclone Roanu which formed over Bay of Bengal during May 2016. The model was run for 72 hours with different CP schemes such as Kain–Fritsch (KF), Betts-Miller-Janjic (BMJ), Grell–Freit as Ensemble (GFE), Grell 3D Ensemble (G3E) and Grell–Devenyi (GD) Ensemble schemes to study the variation in track, intensity. The landfall position error is minimum for BMJ scheme but the time delayed only 1.5-5 hours for all schemes except GD scheme. The Root Mean Square Error (RMSE) and Mean Absolute Error (MAE) of minimum sea level pressure and maximum wind speed is smaller for BMJ, GFE, GD schemes. The RMSE-MAE of rainfall is minimum for BMJ and G3E schemes. Except GD scheme all the other schemes give the better result. Dhaka Univ. J. Sci. 68(1): 87-94, 2020 (January)

scholarly journals Response of Tropical Cyclone Activity and Structure to Global Warming in a High-Resolution Global Nonhydrostatic Model

2017 ◽  
Vol 30 (23) ◽  
pp. 9703-9724 ◽  
Author(s):  
Yohei Yamada ◽  
Masaki Satoh ◽  
Masato Sugi ◽  
Chihiro Kodama ◽  
Akira T. Noda ◽  
...  
Keyword(s):  
Global Warming ◽  
Tropical Cyclone ◽  
Surface Wind ◽  
Atmospheric Model ◽  
Cumulus Parameterization ◽  
Climate Simulation ◽  
Cyclone Activity ◽  
Sea Level Pressure ◽  
Climate Conditions ◽  
Tangential Wind

Future changes in tropical cyclone (TC) activity and structure are investigated using the outputs of a 14-km mesh climate simulation. A set of 30-yr simulations was performed under present-day and warmer climate conditions using a nonhydrostatic icosahedral atmospheric model with explicitly calculated convection. The model projected that the global frequency of TCs is reduced by 22.7%, the ratio of intense TCs is increased by 6.6%, and the precipitation rate within 100 km of the TC center increased by 11.8% under warmer climate conditions. These tendencies are consistent with previous studies using a hydrostatic global model with cumulus parameterization. The responses of vertical and horizontal structures to global warming are investigated for TCs with the same intensity categories. For TCs whose minimum sea level pressure (SLP) reaches less than 980 hPa, the model predicted that tangential wind increases in the outside region of the eyewall. Increases in the tangential wind are related to the elevation of the tropopause caused by global warming. The tropopause rise induces an upward extension of the eyewall, resulting in an increase in latent heating in the upper layers of the inclined eyewall. Thus, SLP is reduced underneath the warmed eyewall regions through hydrostatic adjustment. The altered distribution of SLP enhances tangential winds in the outward region of the eyewall cloud. Hence, this study shows that the horizontal scale of TCs defined by a radius of 12 m s−1 surface wind is projected to increase compared with the same intensity categories for SLP less than 980 hPa.

Ten Demi-Culverins for Aldeburgh: Whitehall, the Dunkirkers, and a Suffolk Fishing Community, 1625–1630

2019 ◽  
Vol 58 (2) ◽  
pp. 315-337 ◽  
Author(s):  
Thomas Cogswell
Keyword(s):  
North Sea ◽  
East Coast ◽  
Central Government ◽  
Fishing Community ◽  
Close Attention ◽  
The North ◽  
The North Sea ◽  
The Impact

AbstractHistorians have not paid close attention to the activities of freebooters operating out of Dunkirk in the late 1620s. This essay corrects that omission by first studying the threat from Dunkirk to England's east coast and then addressing how the central government, counties, and coastal towns responded. A surprisingly rich vein of manuscript material from Great Yarmouth and particularly from the Suffolk fishing community of Aldeburgh informs this case study of the impact of this conflict around the North Sea.

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