We find that long-period variations in tropical cyclone and hurricane frequency over the past century in the North Atlantic Ocean have occurred as three relatively stable regimes separated by sharp transitions. Each regime has seen 50% more cyclones and hurricanes than the previous regime and is associated with a distinct range of sea surface temperatures (SSTs) in the eastern Atlantic Ocean. O...

The basic ingredients for tropical cyclogenesis have been well established: a sufficiently deep warm ocean layer, low-level cyclonic vorticity, weak vertical wind shear, and deep moist convection (e. et al. 2008) have attributed cyclogenesis to a variety of low-level precursor systems that enhance one or more of these ingredients. These studies have traditionally focused on features such as the...

The Madden–Julian oscillation (MJO) influences tropical cyclone formation around the globe. Convectively coupled Kelvin waves are often embedded within the MJO, but their role in tropical cyclogenesis remains uncertain. This case study identifies the influences of the MJO and a series of Kelvin waves on the formation of two tropical cyclones. Typhoons Rammasun and Chataan developed in the weste...

[1] A global high‐resolution (∼40 km) atmospheric general circulation model (ECHAM5 T319) is used to investigate the change of tropical cyclone frequency in the North Pacific under global warming. A time slice method is used in which sea surface temperature fields derived from a lower‐ resolution coupled model run under the 20C3M (in which historical greenhouse gases in 20th century were prescr...

A database of tropical cyclone best track and intensity information for the southwest Pacific Ocean basin is used to construct a 28-year climatology for tropical cyclones that move into middle latitudes. Of the nine or so tropical cyclones that form each year, an average of about three can be expected to migrate south of 358S, with the greatest fraction in March. Storms entering the Tasman Sea ...

Bayesian statistical models were developed for the number of tropical cyclones and the rate at which these cyclones became hurricanes in the North Atlantic. We find that, controlling for the cold tongue index and the North Atlantic oscillation index, there is high probability that the number of cyclones has increased in the past thirty years; but the rate at which these storms become hurricanes...

The interaction of vortex patches in relation to the observed scales and features reported in Part I of this paper is investigated. It is found that the initial approach of compound vortices, such as tropical cyclones, arises from distortion of their, weaker, outer vorticity fields. Care needs to be taken in applying simple concepts, such as the propagation of each vortex on the gradient of its...

T HE DVORAK TECHNIQUE LEGACY. The Dvorak tropical cyclone (TC) intensity estimation technique has been the primary method of monitoring tropical systems for more than three decades. The technique has likely saved tens of thousands of lives in regions where over one billion people are directly affected by TCs (commonly called hurricanes, typhoons, or cyclones). The Dvorak technique’s practical a...

Introduction Conclusions References

Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. [1] We develop a methodology for the frequency of extreme rainfall intensities caused by tropical cyclones (TCs) in...