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...

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 Madden-Julian oscillation (MJO) has been documented in previous studies to significantly impact tropical cyclone activity in all ocean basins. Most of these studies have utilized the Wheeler-Hendon index. This index is only available since 1974, the period over which remotely sensed outgoing longwave radiation data has been available. Our study utilizes a long reconstructed MJO index, based...

The issue of the relationship between the central mean sealevel pressure (Pc) and maximum mean near-surface wind* (the wind-pressure relationship, hereafter WPR) in a tropical cyclone (TC) has been the subject of ongoing debate for many decades and a number of relationships have been developed during this period. This is demonstrated by the fact that the three Australian Tropical Cyclone Warnin...

Improve our understanding of the physical processes by which (a) 3-D environmental shears, in particular the low-level meridional shear and upper-level vertical shear affect inner core structure and intensity, and (b) the mesoscale vortices, outer spiral rainbands, inner spiral rainbands, and the eyewall interact and affect TC development and intensity change. General questions to be addressed ...

Results from a three-layer asymmetric hurricane model previously described by the authors are compared with results from an axially symmetric analog to investigate the effect of the symmetry assumption on the internal dynarnics of model cyclones. The symmetric model storm initially develops more rapidly then the asymmetric storm. The differences in intensity during the first 100 hr are related ...

The long-term goal of this project is to provide probabilistic genesis forecast guidance to operational forecasters and develop a genesis index to provide guidance for operational dynamical model prediction of tropical cyclone (TC) genesis. Once regions of high TC genesis probability are identified, a movable, multi-nested version of the COAMPS with resolution of roughly 3 km or less in the inn...

The long-term goals and objectives of this research are to develop a more complete physical understanding of tropical cyclone (TC) intensity change processes. This year’s work focused on the following three areas: Determining the three-dimensional asymmetric dynamics of the TC core region; Testing hurricane maximum intensity theory; Analyzing the environmental influences on the intensification ...

Correlations between geophysical parameters and tropical cyclones are essential in understanding and predicting the formation of tropical cyclones. Previous studies show that sea surface temperature and vertical wind shear significantly influence the formation and frequent changes of tropical cyclones. This paper presents the utilization of a new approach, data mining, to discover the collectiv...

The destruction wrought by North Atlantic hurricanes in 2004 and 2005 dramatically emphasizes the need for better understanding of tropical cyclone activity apart from the records provided by meteorological data and historical documentation. We present a 220-year record of oxygen isotope values of alpha-cellulose in longleaf pine tree rings that preserves anomalously low isotope values in the l...