The current understanding of internal dynamical processes responsible for tropical cyclone intensity variability is reviewed. These internal dynamic processes are small in horizontal scale and are constrained to chara...The current understanding of internal dynamical processes responsible for tropical cyclone intensity variability is reviewed. These internal dynamic processes are small in horizontal scale and are constrained to characteristics of the vortex itself and less dependent on the environmental and oceanic conditions. Important internal dynamical processes for tropical cyclone evolution are:(i) spiral rainband dynamics,(ii) asymmetric deep convection,(iii) eye/eyewall mixing, and(iv) eyewall replacement cycles. It is shown that while there exists a reasonable understanding of these internal processes in idealized frameworks, there still remains a large gap in our understanding of these processes in the real atmosphere. Additionally, further research is warranted on the interplay of these internal processes with each other as well as their interaction with the environment.展开更多
This contribution summarizes key research advances on tropical cyclone(TC) intensity change from 2014-2018 from the Ninth International Workshop on Tropical Cyclones(IWTC-9). Research advances on intensity change have...This contribution summarizes key research advances on tropical cyclone(TC) intensity change from 2014-2018 from the Ninth International Workshop on Tropical Cyclones(IWTC-9). Research advances on intensity change have occurred on many fronts, including improved understanding of the role of vertical wind shear(VWS) and its impact on convection, surface fluxes, ocean eddies, dry/dusty air intrusions, eyewall replacement cycles(ERCs), spiral rainband dynamics, eyewall instability and inner-core mixing, and the mechanisms by which TCs intensify. This summary highlights a number of these important advances. Additionally, some new and emerging topics on TC intensity change have recently been elucidated: the important role of vortex structure on the subsequent intensification rate, the maximum potential intensification rate(MPIR), and the role of upper level outflow on TC intensity change.展开更多
This contribution summarizes the significant progress in a variety of topic areas related to internal tropical cyclone(TC)intensity change processes over 2018–2022 from the WMO Tenth International Workshop on Tropica...This contribution summarizes the significant progress in a variety of topic areas related to internal tropical cyclone(TC)intensity change processes over 2018–2022 from the WMO Tenth International Workshop on Tropical Cyclones(IWTC-10).These topic areas include surface and boundary layer processes;TC internal structure and microphysical processes;and,radiation interactions with TCs.Recent studies better frame the uncertainty in the surface drag and enthalpy coefficients at high wind speeds.These parameters greatly impact TC intensity and it is therefore important that more direct measurements of these boundary layer parameters are made.Particularly significant scientific strides have been made in TC boundary layers.These advancements have been achieved through improved coupled models,large-eddy simulations,theoretical advance-ments,and detailed observations.It is now clear that the research field needs to better represent the eddy viscosity throughout the depth of the boundary layer.Furthermore,detailed study of coherent structures in TC boundary layers will likely be a propitious direction for the research community.Meanwhile,in-depth observational field campaigns and assiduous data analysis have made significant headway into verifying theory and modeling studies of intensification processes related to TC vortex alignment,efficient latent heating distributions,and overall 3D structure.Substantial efforts have also been made to better understand the intricate roles radiative processes play in TC evolution and intensity change.Finally,some promising progress has been made in the development of time-dependent theories of TC intensification and the predictability of internal TC intensity change.Overall,there have been well-earned gains in the understanding of intensity change processes intrinsic to the TC system,but the journey is not complete.This paper highlights some of the most relevant and important research areas that are still shedding new light into internal factors governing TC intensity change.展开更多
文摘The current understanding of internal dynamical processes responsible for tropical cyclone intensity variability is reviewed. These internal dynamic processes are small in horizontal scale and are constrained to characteristics of the vortex itself and less dependent on the environmental and oceanic conditions. Important internal dynamical processes for tropical cyclone evolution are:(i) spiral rainband dynamics,(ii) asymmetric deep convection,(iii) eye/eyewall mixing, and(iv) eyewall replacement cycles. It is shown that while there exists a reasonable understanding of these internal processes in idealized frameworks, there still remains a large gap in our understanding of these processes in the real atmosphere. Additionally, further research is warranted on the interplay of these internal processes with each other as well as their interaction with the environment.
基金supported by the National Center for Atmospheric Research, which is a major facility sponsored by the National Science Foundation under Cooperative Agreement No. 1852977.
文摘This contribution summarizes key research advances on tropical cyclone(TC) intensity change from 2014-2018 from the Ninth International Workshop on Tropical Cyclones(IWTC-9). Research advances on intensity change have occurred on many fronts, including improved understanding of the role of vertical wind shear(VWS) and its impact on convection, surface fluxes, ocean eddies, dry/dusty air intrusions, eyewall replacement cycles(ERCs), spiral rainband dynamics, eyewall instability and inner-core mixing, and the mechanisms by which TCs intensify. This summary highlights a number of these important advances. Additionally, some new and emerging topics on TC intensity change have recently been elucidated: the important role of vortex structure on the subsequent intensification rate, the maximum potential intensification rate(MPIR), and the role of upper level outflow on TC intensity change.
文摘This contribution summarizes the significant progress in a variety of topic areas related to internal tropical cyclone(TC)intensity change processes over 2018–2022 from the WMO Tenth International Workshop on Tropical Cyclones(IWTC-10).These topic areas include surface and boundary layer processes;TC internal structure and microphysical processes;and,radiation interactions with TCs.Recent studies better frame the uncertainty in the surface drag and enthalpy coefficients at high wind speeds.These parameters greatly impact TC intensity and it is therefore important that more direct measurements of these boundary layer parameters are made.Particularly significant scientific strides have been made in TC boundary layers.These advancements have been achieved through improved coupled models,large-eddy simulations,theoretical advance-ments,and detailed observations.It is now clear that the research field needs to better represent the eddy viscosity throughout the depth of the boundary layer.Furthermore,detailed study of coherent structures in TC boundary layers will likely be a propitious direction for the research community.Meanwhile,in-depth observational field campaigns and assiduous data analysis have made significant headway into verifying theory and modeling studies of intensification processes related to TC vortex alignment,efficient latent heating distributions,and overall 3D structure.Substantial efforts have also been made to better understand the intricate roles radiative processes play in TC evolution and intensity change.Finally,some promising progress has been made in the development of time-dependent theories of TC intensification and the predictability of internal TC intensity change.Overall,there have been well-earned gains in the understanding of intensity change processes intrinsic to the TC system,but the journey is not complete.This paper highlights some of the most relevant and important research areas that are still shedding new light into internal factors governing TC intensity change.
