Tropical Cyclone Structure and Motion

1999 ◽  
Author(s):  
Elizabeth A. Ritchie ◽  
R. L. Elsberry ◽  
P. A. Harr
Keyword(s):  
Tropical Cyclone ◽  
Structure And Motion

scholarly journals Deterministic methods for prediction of tropical cyclone tracks

MAUSAM ◽  
2021 ◽  
Vol 48 (2) ◽  
pp. 257-272
Author(s):  
U.C. MOHANTY ◽  
AKHILESH GUPTA
Keyword(s):  
Tropical Cyclone ◽  
Weather Prediction ◽  
Horizontal Resolution ◽  
Limited Area ◽  
Deterministic Models ◽  
Global Circulation ◽  
Global Circulation Models ◽  
Structure And Motion ◽  
Cyclone Tracks ◽  
Tropical Cyclone Tracks

ABSTRACT. The paper presents a state-of-art review of different objective techniques available for tropical cyclone track prediction. A brief description of current theories of tropical cyclone motion is given. Deterministic models with statistical and dynamical methods have been discussed. Recent advances in the understanding of cyclone structure and motion aspects have led to improved prediction of tropical cyclones. There has been considerable progress in the field of prediction by dynamical methods. High resolution Limited Area Models (LAM) as well as Global Circulation Models (GCM) are now being used extensively by most of the leading operational numerical weather prediction (NWP) centres in the world The major achievements towards improvement of such models have come from improved horizontal resolution of the models, inclusion of physical processes, use of synthetic and other non-conventional data in the data assimilation schemes and nudging method for initial matching of analysed cyclone centres with corresponding observations. A brief description of further improvement in deterministic approach for prediction of tropical cyclone tracks is outlined.  

scholarly journals Influence of Cloud Microphysics and Radiation on Tropical Cyclone Structure and Motion

2016 ◽  
Vol 56 ◽  
pp. 11.1-11.27 ◽  
Author(s):  
Robert G. Fovell ◽  
Yizhe Peggy Bu ◽  
Kristen L. Corbosiero ◽  
Wen-wen Tung ◽  
Yang Cao ◽  
...  
Keyword(s):  
Tropical Cyclone ◽  
Wind Field ◽  
Radiative Forcing ◽  
Inner Core ◽  
Longwave Radiation ◽  
Outer Core ◽  
Cloud Microphysics ◽  
Convective Activity ◽  
Radiative Processes ◽  
Structure And Motion

Abstract The authors survey a series of modeling studies that have examined the influences that cloud microphysical processes can have on tropical cyclone (TC) motion, the strength and breadth of the wind field, inner-core diabatic heating asymmetries, outer-core convective activity, and the characteristics of the TC anvil cloud. These characteristics are sensitive to the microphysical parameterization (MP) in large part owing to the cloud-radiative forcing (CRF), the interaction of hydrometeors with radiation. The most influential component of CRF is that due to absorption and emission of longwave radiation in the anvil, which via gentle lifting directly encourages the more extensive convective activity that then leads to a radial expansion of the TC wind field. On a curved Earth, the magnitude of the outer winds helps determine the speed and direction of TC motion via the beta drift. CRF also influences TC motion by determining how convective asymmetries develop in the TC inner core. Further improvements in TC forecasting may require improved understanding and representation of cloud-radiative processes in operational models, and more comprehensive comparisons with observations are clearly needed.

scholarly journals The Effects of the Full Coriolis Force on the Structure and Motion of a Tropical Cyclone. Part I: Effects due to Vertical Motion

2005 ◽  
Vol 62 (10) ◽  
pp. 3825-3830 ◽  
Author(s):  
Xudong Liang ◽  
Johnny C. L. Chan
Keyword(s):  
Tropical Cyclone ◽  
Coriolis Force ◽  
Mesoscale Model ◽  
Vertical Motion ◽  
Momentum Equation ◽  
Scale Analysis ◽  
State University ◽  
Structure And Motion ◽  
Fifth Generation ◽  
Wind Structure

Abstract In most dynamical studies of synoptic-scale phenomena, only the components of the Coriolis force contributed by the horizontal motion are considered, and only in the horizontal momentum equation. The other components are neglected based on a scale analysis. However, it is shown that such an analysis may not be fully valid in a tropical cyclone (TC) and that these terms should be included. The two neglected terms are 1) ew, the Coriolis force in the x-momentum equation due to vertical motion, and 2) we, the Coriolis force in the vertical equation of motion due to the zonal wind. In this paper, effects of the first term (i.e., ew) on the structure and motion of a TC are investigated through numerical simulations using the fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5). The results suggest that after the ew term has been included, the structure of a TC even on an f plane is changed. A southwestward displacement of a TC center with a speed of ∼1 km h−1 is found in the f-plane experiment. On a β plane, inclusion of the ew term gives a vortex track that is generally west to southwest of the inherent northwestward track (due to the β effect). A scale analysis suggests that the ew term can be as large as half the magnitude of the horizontal acceleration. This term generates an asymmetric wind structure with a generally easterly flow near the center, which therefore causes the vortex to displace toward the southwest. A rainfall asymmetry consistent with the convergence associated with the wind asymmetry is also found and accounts for 10%–20% of the symmetric parts.

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