«

jan 11

images of orissa super cyclone 1999

In order to test the model response A number of observational/empirical studies were conducted at different basins to investigate the influence of SST In the control run (CONTROL), the WRF model is initialized without coupling. The advanced microwave sounding unit (AMSU), in addition to providing very valuable data over non-precipitating cloudy regions, can provide very high horizontal resolution of the temperature and humidity soundings. was found to increase the air–sea heat fluxes over the cyclonic region, which resulted in the improved conditions. Both models failed to produce As an interesting by-product, it is shown that a very simplistic and computationally highly efficient convective parameterization scheme leads to a very realistic simulation of the MCS, if the scheme uses a stability closure, assumes a large cloud size, parameterizes moist downdrafts, and does not assume unrealistically large lateral mixing. It has a uniform grid system with a horizontal resolution of about 50km and 8 vertical levels and covers the area of 4000km×4000km. There were no significant differences in the spatial distribution of precipitation the rainy area better compared to those produced by Weather Research and Forecasting Model. Most importantly, the landfall points of these storms are well simulated by the model though the time of landfall delays from actual landfall time as reported by India Meteorology Department (IMD) at an average by five hours. The β-effect on tropical cyclone motion is studied using an analytical as well as a numerical model in a nondivergent barotropic framework. The purpose of this paper is to evaluate the performance of the new forecasting system on the analysis and forecasting of easterly waves and their associated tropical storms over Africa and the tropical Atlantic. The impact of assimilating the AMSU-derived temperature and humidity vertical profiles in a mesoscale model has not been tested yet over the Indian region. The role of graupel is further established by deactivating its production, where the model cannot simulate the midlevel heating and intensification of the system. The objective of this study is to investigate the impact of ingesting and assimilating the AMSU data together with conventional upper air and surface meteorological observations over India on the prediction of a tropical cyclone which formed over the Arabian Sea during November 2003 using analysis nudging. The sensitivity of parameterized convection in these models on precipitation forecast skill is studied using two different parameterization schemes for cumulus convection (the Relaxed Arakawa-Schubert scheme and the modified Kuo scheme). 1] The prediction of the intensification and movement of the Orissa Super Cyclone (OSC-1999) was studied using the National Center for Atmospheric Research MM5 mesoscale atmospheric model. While the lowest central pressure estimated from the satellite image is 988 hPa, are conducted in this study. Secondly, the study also investigated the model performance based on the best possible combinations of model physics on the real-time forecasts of four BoB cyclones (Phailin, Helen, Lehar, and Madi) that made landfall during 2013 based on another 15 numerical simulations. Four cloud microphysics parameterization schemes, namely mixed phase Over 900 people had perished then. Additionally, radiative clear-air cooling helped the convection by continuously destabilizing the troposphere and countering the warming effect of convective updrafts. The characteristics of wind at 850 hPa and 200 hPa, temperature at 500 hPa, overestimated by Sc. The simulated cyclone with Gr scheme has the Bowen ratios ranged from 0.11 to 0.16 in the inner 50 n mi of the storm and extensive areas of radar “bright band” characterized the stor... Because a storm's circulation is not well analyzed operationally, due to a lack of observations, a procedure was developed to insert an idealized vortex into the initial analysis. the model. Approximately 275,000 homes were destroyed leaving 1.67 … The objective of the present study is to investigate in detail the sensitivity of cumulus parameterization (CP), planetary boundary layer (PBL) parameterization, microphysics parameterization (MP) on the numerical simulation of severe cyclone LAILA over Bay of Bengal using Weather Research & Forecasting (WRF) model. as heavy monsoon rainfall, tropical cyclone genesis and movement and severe local thunderstorms, as the processes controlling and a weak cyclonic circulation associated with feeble low pressure area over south peninsular India. However, the convection schemes lacked skill in predicting the correct placement of the area and amount for the high precipitation threshold greater than 40 mm day –1 . Case study of super cyclone in orissa 1999. Daily rainfall analysis also shows that the high-resolution model is capable of capturing the active and break phases during the El Niño and La Niña seasons. Low precipitation threshold of rainfall less than 2 mm day–1 was successfully predicted by both versions of the FSU model. The extent of the damage is difficult to determine. People of the state capital Bhubaneswar as well as the coastal villages of Puri, Jagatsinghpur, Cuttack and Kendrapara districts who faced the wrath of the extremely severe Cyclone Fani on Friday were drawing comparisons with the devastation caused by the 1999 Odisha Super Cyclone. In order to provide an adequate “We are scared of ingress of tidal waves. In the first experiment the model is integrated with a synthetic vortex based on Rankine wind profile while in the The initialization of the different estimates of the MLD in the WRF-OML shows that the TC intensity and translation speed are sensitive to the initial representation of the MLD for the post-monsoon storm. Observed SST shows a number of warm patches in the Bay of Bengal compared with NCEP skin temperature. this purpose the FGGE level-III b data set, produced at ECM WF, UK is used. The slope of the Convective parameterization schemes (CPS) include Grell (Gr), Betts–Miller (BM) Be it Sandhakuda fishing village near Paradip or Kharinasi hamlet in Kendrapara, the scene is invariably the same. Bound with page 144 missing. The model was integrated for 5 days, and the model-predicted intensity and track positions were compared with observations. sensitivity runs Providing reasonably accurate initial condition to tropical cyclone forecast models has always been a problem to numerical weather forecasters. There were 12 active TCs during this period. Patra et al. Further evaluation of the predictive skills showed that the Relaxed Arakawa-Schubert scheme was a consistently better predictor of rainfall due to its low bias and lower root mean square errors (RMSEs) compared to the modified Kuo parameterization scheme. forecast of cyclones. (QSCAT), Special Sensor Microwave Imager (SSM/I) winds, conventional surface, and upper air meteorological observations. by a global spectral model. It is found that the forecast track and intensity of the cyclone are most sensitive Model. The MY scheme produced reasonably conditions. We faced Phailin, Hudhud, Titli cyclones stubbornly in the recent years and have encountered cyclonic situation over a dozen of times in the past six to seven years,” recounted S. Ramamurthy, a fisherman in Sandhakuda. Wind speed is also picking up. A super cyclone hit Orissa coast during 24-31 Oct. 1999 causing vast damage to property and life. Analysis of polar diagrams comprising of hourly PPI images taken between 280800 UTC and 290200 UTC reveals interesting aspects of development of this Super Cyclone in terms of waxing and waning of eye the associated rainfall is reduced by about 30% with the introduction of 10 cm of snow over the Tibetan region in the month sensitivity of model simulation/forecast to SST, it is not well quantified, particularly for Bay of
downplayed the horrendous impact on the lives of the people. third domain. -from Authors. Numerical simulations are performed using the Penn State University/ National Center for Atmospheric Research Mesoscale Model (MM5) to study the impact of initial conditions on the super cyclone which hit the coast of Orissa in 1999. of the cyclone. The ABL turbulence parameterizations examined are the Blackadar scheme coupled to a simple soil slab found that the coupling of the NSM with the Troen-Mahrt ABL scheme leads to excessive ABL mixing and a dry bias in the model This model predicts the central pressures and movements of several typhoons observed in 1985 with a fairly good skill. that RegCM3 is very much sensitive to Tibetan snow. It struck the coast of Odisha with an height of in 1999 was 26 feet (8 meters). the lowest layer at the RMW; 6) the slope of the RMW with height is All feedback and static-control assumptions tested here seem very important for the prediction of sea level pressure and rainfall. documents in a water proof cover and store it high click:-Satellite Images - Weather. In the first one, called Control run, the National A control run is presented, which shows good agreement with observations in many aspects. QSCAT Some impact studies suggest that particular attention should be paid for the accuracy of the manual analyses and the performance of the hemispheric model (background model), because they have large effects on the track performance of this model. A high-resolution short-term model forecast initialized at 1800 UTC 2 August 1997 was made using the fifth-generation Pennsylvania State University-NCAR nonhydrostatic, two-way interactive, movable, triply nested grid Mesoscale Model (MM5). In addition, the effect of cumulus parameterization schemes at different resolution (27 and 9 km) on the cyclone track and intensity is reported. weather disturbances over the Indian region. All rights reserved. Using a spectral-type cumulus parameterization that includes moist downdrafts within a three-dimensional mesoscale model, various disparate closure assumptions are systematically tested within the generalized framework of dynamic control, static control, and feedback. The inner core structure and evolution of Hurricane Guillermo (1997) over a 120 km by 120 km square area, centered on the storm, was observed by the P-3 aircraft during 10 flight legs at half-hour intervals during a 6-h, It is well recognized that sea surface temperature (SST) plays a dominant role in the formation and intensification of tropical Super Cyclone Amphan became the strongest storm ever recorded in the Bay of Bengal on May 18, after intensifying with sustained wind speeds of up to 270 kilometers per hour (165 miles per hours). In this study, PSU/NCAR mesoscale model MM5 is used to produce 5-day simulation of the super cyclone that crossed Orissa coast on 29 October 1999. we do note a considerable variation in intensity forecast due to variations in PBL schemes. The FDDAALL The latent heat released in the formation of graupel mixing ratio is responsible for net middle level heating rate in the cyclone core. It also has simulated the diverging winds at lower levels associated with downdraft https://www.ndtv.com/video/special/news/the-orissa-super-cyclone-284476 To read the full-text of this research, you can request a copy directly from the authors. For several years the UK Met. The results for the November 2002 cyclone with the Rankine vortex showed greater vertical wind speed as compared to the Holland vortex. On 28 September when the storm was most intense, the inflow layer appeared to extend no higher the 750 mb level. Although this has yielded acceptable results, in terms of the verification of TC tracks in the short and medium range, it was felt certain improvements could be made. The wind speed ranged from 260 kmph to 300 kmph and all that could be done was to get ripped by the winds and waters. All four cyclones studied here show that the Holland vortex has produced a stronger cyclone in terms of the minimum sea-level pressure and maximum wind speed. location of the center of the system have contributed to considerable reduction in the vector track prediction errors ie. the corresponding value in the synthetic vortex simulated cyclone is 993 hPa. the intensity of the storm with large error in its track and landfall position. Office has initialised tropical cyclones (TCs) in its global model by use of ‘bogus’ observations representing a simple symmetric vortex. Gathering speed, Fani is rolling menacingly towards Odisha coast and likely to make landfall, with a wind speed of nearly 200 kmph, close to Gopalpur near the holy town of Puri between 8-10 am. experiments (totally 11 experiments) are conducted to examine the impact of each of the aforementioned parameterization schemes K E Y W O R D S hydrostatic core, Indian summer monsoon, non-hydrostatic core, RegCM. The prediction of the intensification and movement of the Orissa Super Cyclone (OSC-1999) was studied using the National Center for Atmospheric Research MM5 mesoscale atmospheric model. features and associated rainfall. The area is almost impossible to reach, as the cyclone has torn down bridges and made roads and railways impassable. On October 29, 1999 a super cyclone struck Odisha, causing widespread destruction, with at least 10,000 lives lost and an estimated 1.5 million people rendered homeless. In addition, the resolution was increased substantially to a triangular truncation at T106. The new scheme was introduced operationally on 25 October 1994. observed SST over the Bay of Bengal are 1–2°C warmer than climatological SST, but cooler by nearly 1°C along the coastline. In CP sensitivity experiments, the track and intensity is well simulated by Betts-Miller-Janjic (BMJ) schemes. All rights reserved. wind alone was used in the third simulation (FDDAQSCAT), the SSM/I wind alone in the fourth (FDDASSMI) and the conventional deepening storm over the Bay of Bengal, i.e., Orissa super cyclone (1999). on the storm’s track and intensity forecast. At least 12 lakh people were evacuated in the wake of Cyclone Fani, which claimed eight lives on Friday. Hurricane flight data are used to augment the analyses in the inner regions. Two numerical experiments are designed in this study for each of the above four two vortices are used in the sensitivity studies to simulate two cyclones, one of May 1979 and the other of August 1979. The tropical cyclones form over the oceanic regions where conventional meteorological observations are not available. Bengal cyclones. The experimental model uses primitive equations in σ coordinate. studies confirmed the, In this study, the fifth-generation Pennsylvania State University–National Center for Atmospheric Research The Root Mean Square Error (RMSE) for Minimum Central Pressure (MCP) was about 6 hPa and the same noticed for Maximum Surface Wind (MSW) was about 4.5 m s⁻¹ noticed during the entire simulation period. of four tropical cyclones, which formed over the Bay of Bengal during November 2002 and 2005, December 2005 and over the Arabian 2004; Hari Prasad 2006, 2007; Bhaskar Rao et al. Results of the sensitivity tests are compared to observations in terms of sea level pressure, rainfall patterns, and domain-averaged bias errors (compared to the control run) of various properties. The entire coastal belt plunged into darkness, road communication cut off and just like in 1999, flow of information related to the cyclone stopped despite all technological advancement and internet penetration. Strong intensity is produced by KF, New Grell (NG) schemes and weak intensity is produced by Betts-Miller-Janjic (BMJ) scheme with all microphysics parameterization (MP) combinations. The representation of the mid-tropospheric heating in WSM6 is mainly controlled by amount of graupel hydrometeor and thus might be one of the possible causes in modulating the storm’s intensity. A nonhydrostatic extension to the Pennsylvania State University-NCAR Mesoscale Model is presented, which employs reference pressure as the basis for a terrain-following vertical coordinate, and the fully compressible system of equations. Key words − Super cyclone, Gale force winds, Microwave images, RMR, QLM, Storm surge, Disaster management. Numerical studies of OSC-99 using MM5 are available in the literature (Mohanty et al., 2004; ... Patra et al. (TPW) to investigate their individual impact on cyclone intensity and track. There were no significant differences in the spatial distribution of precipitation for the two experiments corresponding to all four cyclones. core structure of Orissa super cyclone (1999) in Bay of Bengal (north and occur just inside the eye-wall cloud edge where the sinking is A case study of the OSC has been chosen as it is noted to be the most intense cyclone over the Bay of Bengal of this century. resolution) is utilized. The model has been simulated for the period June–August for 1997 and 2002, of which 1997 was an ENSO year and 2002 was a drought year. Their study reports a good simulation of the Orissa super cyclone but with an underestimate of cyclone intensity. which KF2 is used as CPS and another in which no CPS is used in the prevented it from making much of an impact on track prediction. climatological SST, NCEP (National Center for Environmental Prediction) skin temperature as SST, and observed SST (satellite The Holland vortex showed a better vertical structure of wind speed in the longitudinal height section at 24 hours of forecast for the November 2005 cyclone while the structure was better for the Rankine vortex for the remaining two cyclones. moisture. With better specification of the initial vortex structure, the model successfully simulated the typical tropical cyclone characteristics, such as asymmetries in the wind field: the strongest winds occurred in the east and close to the cyclone's centre, strong wind gradients were found between the centre and the maximum wind region, and there was a slow decrease in wind speed up to the middle troposphere. to investigate the influence of Special Sensor Microwave Imager (SSM/I) and Quick Scatterometer (Quik- model (SSM), and the Troen-Mahrt scheme coupled to SSM or to the more sophisticated Noah land-surface model (NSM). to capture the trend in the observed data, the computed results deviate from observations. One way of overcoming the above problem is to modify the initial analysis by replacing the weak and ill-defined vortex in the initial analysis with a synthetic vortex having the correct size and intensity at the correct location. How deadly was 1999 Odisha super cyclone? The track and intensity of the storm is better simulated with the use of satellite-observed SST. Most tropical cyclones have very few observations in their vicinity. cyclones simulated with Rankine vortex are found to be on the left side of the observed track while that of Holland’s vortex the clouding in satellite cloud images. Total three sets of experiments are performed. 33 refs., 11 figs., 1 tab.

Deixe uma resposta