On an analytical model for the rapid intensification of tropical cyclones

2010 ◽  
Vol 136 (647) ◽  
pp. 549-551 ◽  
Author(s):  
Michael T. Montgomery ◽  
Roger K. Smith
Keyword(s):  
Tropical Cyclones ◽  
Analytical Model ◽  
Rapid Intensification

scholarly journals Are Special Processes at Work in the Rapid Intensification of Tropical Cyclones?

2015 ◽  
Vol 143 (3) ◽  
pp. 878-882 ◽  
Author(s):  
Roman Kowch ◽  
Kerry Emanuel
Keyword(s):  
Tropical Cyclone ◽  
Tropical Cyclones ◽  
Internal Variability ◽  
Open Ocean ◽  
Rapid Intensification ◽  
Exponential Distributions ◽  
Frequency Distributions ◽  
Fat Tail ◽  
Dissipation Rates ◽  
Special Factors

Abstract Probably not. Frequency distributions of intensification and dissipation developed from synthetic open-ocean tropical cyclone data show no evidence of significant departures from exponential distributions, though there is some evidence for a fat tail of dissipation rates. This suggests that no special factors govern high intensification rates and that tropical cyclone intensification and dissipation are controlled by statistically random environmental and internal variability.

Why does rapid contraction of the radius of maximum wind precede rapid intensification in tropical cyclones?

2021 ◽  
Author(s):  
Yuanlong Li ◽  
Yuqing Wang ◽  
Yanluan Lin ◽  
Xin Wang
Keyword(s):  
Tropical Cyclones ◽  
Radial Distribution ◽  
Diabatic Heating ◽  
Rate Of Change ◽  
Rapid Intensification ◽  
Absolute Vorticity ◽  
Radial Gradient ◽  
Maximum Wind ◽  
Tangential Wind ◽  
Vorticity Flux

AbstractThe radius of maximum wind (RMW) has been found to contract rapidly well preceding rapid intensification in tropical cyclones (TCs) in recent literature but the understanding of the involved dynamics is incomplete. In this study, this phenomenon is revisited based on ensemble axisymmetric numerical simulations. Consistent with previous studies, because the absolute angular momentum (AAM) is not conserved following the RMW, the phenomenon can not be understood based on the AAM-based dynamics. Both budgets of tangential wind and the rate of change in the RMW are shown to provide dynamical insights into the simulated relationship between the rapid intensification and rapid RMW contraction. During the rapid RMW contraction stage, due to the weak TC intensity and large RMW, the moderate negative radial gradient of radial vorticity flux and small curvature of the radial distribution of tangential wind near the RMW favor rapid RMW contraction but weak diabatic heating far inside the RMW leads to weak low-level inflow and small radial absolute vorticity flux near the RMW and thus a relatively small intensification rate. As RMW contraction continues and TC intensity increases, diabatic heating inside the RMW and radial inflow near the RMW increase, leading to a substantial increase in radial absolute vorticity flux near the RMW and thus the rapid TC intensification. However, the RMW contraction rate decreases rapidly due to the rapid increase in the curvature of the radial distribution of tangential wind near the RMW as the TC intensifies rapidly and RMW decreases.

scholarly journals The Unexpected Rapid Intensification of Tropical Cyclones in Moderate Vertical Wind Shear. Part I: Overview and Observations

2018 ◽  
Vol 146 (11) ◽  
pp. 3773-3800 ◽  
Author(s):  
David R. Ryglicki ◽  
Joshua H. Cossuth ◽  
Daniel Hodyss ◽  
James D. Doyle
Keyword(s):  
Tropical Cyclones ◽  
Wind Shear ◽  
Vertical Wind Shear ◽  
Convective Cloud ◽  
Vertical Wind ◽  
Rapid Intensification ◽  
Brightness Temperatures ◽  
Idealized Modeling ◽  
Hurricane Prediction ◽  
Upper Level

Abstract A satellite-based investigation is performed of a class of tropical cyclones (TCs) that unexpectedly undergo rapid intensification (RI) in moderate vertical wind shear between 5 and 10 m s−1 calculated as 200–850-hPa shear. This study makes use of both infrared (IR; 11 μm) and water vapor (WV; 6.5 μm) geostationary satellite data, the Statistical Hurricane Prediction Intensity System (SHIPS), and model reanalyses to highlight commonalities of the six TCs. The commonalities serve as predictive guides for forecasters and common features that can be used to constrain and verify idealized modeling studies. Each of the TCs exhibits a convective cloud structure that is identified as a tilt-modulated convective asymmetry (TCA). These TCAs share similar shapes, upshear-relative positions, and IR cloud-top temperatures (below −70°C). They pulse over the core of the TC with a periodicity of between 4 and 8 h. Using WV satellite imagery, two additional features identified are asymmetric warming/drying upshear of the TC relative to downshear, as well as radially thin arc-shaped clouds on the upshear side. The WV brightness temperatures of these arcs are between −40° and −60°C. All of the TCs are sheared by upper-level anticyclones, which limits the strongest environmental winds to near the tropopause.

scholarly journals High-Resolution Ensemble HFV3 Forecasts of Hurricane Michael (2018): Rapid Intensification in Shear

2020 ◽  
Vol 148 (5) ◽  
pp. 2009-2032 ◽  
Author(s):  
Andrew T. Hazelton ◽  
Xuejin Zhang ◽  
Sundararaman Gopalakrishnan ◽  
William Ramstrom ◽  
Frank Marks ◽  
...  
Keyword(s):  
Tropical Cyclones ◽  
Early Stage ◽  
Vertical Wind Shear ◽  
Vertical Shear ◽  
Rapid Intensification ◽  
Forecast System ◽  
The Mean ◽  
Cubed Sphere ◽  
Environmental Prediction ◽  
The Relationship

Abstract The FV3GFS is the current operational Global Forecast System (GFS) at the National Centers for Environmental Prediction (NCEP), which combines a finite-volume cubed sphere dynamical core (FV3) and GFS physics. In this study, FV3GFS is used to gain understanding of rapid intensification (RI) of tropical cyclones (TCs) in shear. The analysis demonstrates the importance of TC structure in a complex system like Hurricane Michael, which intensified to a category 5 hurricane over the Gulf of Mexico despite over 20 kt (10 m s−1) of vertical wind shear. Michael’s RI is examined using a global-nest FV3GFS ensemble with the nest at 3-km resolution. The ensemble shows a range of peak intensities from 77 to 159 kt (40–82 m s−1). Precipitation symmetry, vortex tilt, moisture, and other aspects of Michael’s evolution are compared through composites of stronger and weaker members. The 850–200-hPa vertical shear is 22 kt (11 m s−1) in the mean of both strong and weak members during the early stage. Tilt and moisture are two distinguishing factors between strong and weak members. The relationship between vortex tilt and humidification is complex, and other studies have shown both are important for sheared intensification. Here, it is shown that tilt reduction leads to upshear humidification and is thus a driving factor for intensification. A stronger initial vortex and early evolution of the vortex also appear to be the key to members that are able to resist the sheared environment.

The Role of WISHE in the Rapid Intensification of Tropical Cyclones

2020 ◽  
Vol 77 (9) ◽  
pp. 3139-3160
Author(s):  
Chieh-Jen Cheng ◽  
Chun-Chieh Wu
Keyword(s):  
Tropical Cyclones ◽  
Potential Temperature ◽  
Surface Heat ◽  
Surface Fluxes ◽  
Heat Fluxes ◽  
Rapid Intensification ◽  
Surface Heat Fluxes ◽  
Peak Intensity ◽  
Before And After

Abstract This study examines the role of surface heat fluxes, particularly in relation to the wind-induced surface heat exchange (WISHE) mechanism, in the rapid intensification (RI) of tropical cyclones (TCs). Sensitivity experiments with capped surface fluxes and thus reduced WISHE exhibit delayed RI and weaker peak intensity, while WISHE could affect the evolutions of TCs both before and after the onset of RI. Before RI, more WISHE leads to faster increase of equivalent potential temperature in the lower levels, resulting in more active and stronger convection. In addition, TCs in experiments with more WISHE reach a certain strength earlier, before the onset of RI. During the RI period, more surface heat fluxes could provide convective instability in the lower levels, and cause a consequent development in the convective activity. More efficient intensification in a TC is found with higher surface heat fluxes and larger inertial stability, leading to a stronger peak intensity, more significant and deeper warm core in TC center, and the axisymmetrization of convection in the higher levels. In both stages, different levels of WISHE alter the thermodynamic environment and convective-scale processes. In all, this study supports the crucial role of WISHE in affecting TC intensification rate for TCs with RI.

scholarly journals Is the State of the Air‐Sea Interface a Factor in Rapid Intensification and Rapid Decline of Tropical Cyclones?

2017 ◽  
Vol 122 (12) ◽  
pp. 10174-10183 ◽  
Author(s):  
Alexander V. Soloviev ◽  
Roger Lukas ◽  
Mark A. Donelan ◽  
Brian K. Haus ◽  
Isaac Ginis
Keyword(s):  
Tropical Cyclones ◽  
The State ◽  
Rapid Decline ◽  
Rapid Intensification

Eye on China

2020 ◽  
Vol 24 (02) ◽  
pp. 6-12
Keyword(s):  
Tropical Cyclones ◽  
Chemical Structure ◽  
African Swine Fever Virus ◽  
Modern Science ◽  
African Swine Fever ◽  
Rapid Intensification ◽  
Science City ◽  
Chinese Academy Of Sciences ◽  
Inflammatory Bowel ◽  
Academy Of Sciences

The following topics are under this section: New Mechanism in Pathogenesis of Inflammatory Bowel Disease for Possible Therapeutic Targets Prediction of Tropical Cyclones Undergoing Rapid Intensification New Methodology for Determining Molecular Chemical Structure Chinese Academy of Sciences Showcase Thousand-ton Scale Solar Fuel Synthesis Insights to DNA Sequence of African Swine Fever Virus Developing Beijing’s Modern Science City China Completes Construction of Hospital in Record Time to Combat Wuhan Virus

scholarly journals On the processes influencing rapid intensity changes of tropical cyclones over the Bay of Bengal

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Saiprasanth Bhalachandran ◽  
R. Nadimpalli ◽  
K. K. Osuri ◽  
F. D. Marks ◽  
S. Gopalakrishnan ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Tropical Cyclones ◽  
Bay Of Bengal ◽  
Rapid Intensification ◽  
Eddy Flux ◽  
Relative Proximity ◽  
Intensity Changes ◽  
Primary Finding ◽  
Asymmetrically Distributed ◽  
Left Quadrant

AbstractWe present a numerical investigation of the processes that influenced the contrasting rapid intensity changes in Tropical Cyclones (TC) Phailin and Lehar (2013) over the Bay of Bengal. Our emphasis is on the significant differences in the environments experienced by the TCs within a few weeks and the consequent differences in their organization of vortex-scale convection that resulted in their different rapid intensity changes. The storm-relative proximity, intensity, and depth of the subtropical ridge resulted in the establishment of a low-sheared environment for Phailin and a high-sheared environment for Lehar. Our primary finding here is that in Lehar’s sheared vortex, the juxtaposition in the azimuthal phasing of the asymmetrically distributed downward eddy flux of moist-entropy through the top of the boundary layer, and the radial eddy flux of moist-entropy within the boundary layer in the upshear left-quadrant of Lehar (40–80 km radius) establishes a pathway for the low moist-entropy air to intrude into the vortex from the environment. Conversely, when the azimuthal variations in boundary layer moist-entropy, inflow, and convection are weak in Phailin’s low-sheared environment, the inflow magnitude and radial location of boundary layer convergence relative to the radius of maximum wind dictated the rapid intensification.

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