scholarly journals Prediction of tropical cyclones by numerical models A review

MAUSAM ◽  
2021 ◽  
Vol 48 (2) ◽  
pp. 225-238
Author(s):  
K. PRASAD
Keyword(s):  
Numerical Models ◽  
Forecast Model ◽  
Limited Area ◽  
Cyclone Track ◽  
Dynamical Models ◽  
Physical Processes ◽  
Primitive Equation ◽  
Recent Developments ◽  
Synthetic Vortex ◽  
Current Emphasis

ABSTRACT. This paper contains a review of some past and recent developments in cyclone track prediction problem by dynamical models. The early attempts aimed at predicting tropical cyclone motion by using simple barotropic models based on vertically integrated vorticity tendency equation. Barotropic models are still used operationally in some centres due to their simplicity. However, current emphasis is on advanced primitive equation models incorporating physical processes, like cumulus convection, which are necessary to account for a major component of the cyclone movement. An important aspect of cyclone prediction by dynamical models is prescription of a correctly analysed synthetic vortex in the initial fields for running a forecast model. Several approaches developed by various groups for generating synthetic vortex are discussed. Examples of some cases of track prediction by limited area model in IMD and by global models are illustrated.    

scholarly journals NUMERICAL MODELING OF OPTICAL PROPERTIES INSIDE THE SURFZONE

2011 ◽  
Vol 1 (32) ◽  
pp. 51
Author(s):  
Fengyan Shi ◽  
Gangfeng Ma ◽  
James T. Kirby
Keyword(s):  
Optical Properties ◽  
Numerical Models ◽  
Turbulence Models ◽  
Fluid Models ◽  
Physical Processes ◽  
Bubble Entrainment ◽  
Recent Developments ◽  
Model Components ◽  
2D And 3D ◽  
Two Fluid

This paper provides a review of our recent developments in numerical models for predicting physical processes related to optical properties inside the surfzone. Model components in the developments include the bubble entrainment model, 2D and 3D multiphase two-fluid models for modeling quiescent phase of bubbles, turbulence models with influences of bubbles, bubble coalescence and breakup models used in the two-fluid models, and foam model for predicting foam patch generation and evolution inside the surfzone. The paper summarizes theories used in the model components and shows some numerical results from model tests.

scholarly journals Tropical cyclone track prediction by a high resolution limited area model using synthetic observations

MAUSAM ◽  
2021 ◽  
Vol 48 (3) ◽  
pp. 351-366
Author(s):  
K. PRASAD ◽  
Y.V. RAMA RAO ◽  
SANJIB SEN
Keyword(s):  
High Resolution ◽  
Tropical Cyclone ◽  
Tropical Cyclones ◽  
Weather Prediction ◽  
Forecast Model ◽  
Limited Area ◽  
Forecast Errors ◽  
Cyclone Track ◽  
Tropical Cyclone Track ◽  
Humidity Field

ABSTRACT. Results of tropical cyclone track prediction experiments in die Indian seas by a high resolution limited area numerical weather prediction model (1° × 1° lat./long. grid) are presented. As the tropical cyclones form in data sparse regions of tropical oceans, and are, therefore, not well analysed in die initial fields, a scheme has been developed for generation of synthetic observations -based on die empirical structure of tropical cyclones, and their assimilation into the objective analysis, for preparing initial fields for running a forecast model. Experiments on track prediction have beat : conducted for die cyclones forming in the Bay of Bengal and Arabian Sea during the period 1990-95. Forecast errors of the model for 24 hr and 48 hr forecasts have been computed. A sensitivity experiment has been carried out to demonstrate the importance of initial humidity field on forecast model performance. The experiment brings out crucial important of the initial humidity field prescription in accurate track prediction by die forecast model.    

scholarly journals Precipitation downscaling under climate change: Recent developments to bridge the gap between dynamical models and the end user

2010 ◽  
Vol 48 (3) ◽  
Author(s):  
D. Maraun ◽  
F. Wetterhall ◽  
A. M. Ireson ◽  
R. E. Chandler ◽  
E. J. Kendon ◽  
...  
Keyword(s):  
Climate Change ◽  
End User ◽  
Dynamical Models ◽  
Recent Developments

scholarly journals A Review of Hydraulic Fracturing Simulation

2021 ◽  
Author(s):  
Bin Chen ◽  
Beatriz Ramos Barboza ◽  
Yanan Sun ◽  
Jie Bai ◽  
Hywel R Thomas ◽  
...  
Keyword(s):  
Hydraulic Fracturing ◽  
State Of The Art ◽  
Numerical Models ◽  
Gas Production ◽  
Physical Processes ◽  
Horizontal Drilling ◽  
Improve Treatment ◽  
Multi Stage ◽  
Pros And Cons ◽  
Treatment Designs

AbstractAlong with horizontal drilling techniques, multi-stage hydraulic fracturing has improved shale gas production significantly in past decades. In order to understand the mechanism of hydraulic fracturing and improve treatment designs, it is critical to conduct modelling to predict stimulated fractures. In this paper, related physical processes in hydraulic fracturing are firstly discussed and their effects on hydraulic fracturing processes are analysed. Then historical and state of the art numerical models for hydraulic fracturing are reviewed, to highlight the pros and cons of different numerical methods. Next, commercially available software for hydraulic fracturing design are discussed and key features are summarised. Finally, we draw conclusions from the previous discussions in relation to physics, method and applications and provide recommendations for further research.

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>

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