Investigating changes in global tropical cyclone storm frequency and intensity

Understanding fluctuations in tropical cyclone activity along United States shores and abroad becomes increasinglyimportant as coastal managers and planners seek to save lives, mitigate damage, and plan for resilience in the face of changing storminess and sea-level rise. Tropical cyclone activity has long been of concern to coastal areas as theybring strong winds, heavy rains, and high seas. Given projections of a warming climate, current estimates suggestthat not only will tropical cyclones increase in frequency, but also in intensity (maximum sustained winds andminimum central pressures). An understanding of what has happened historically is an important step in identifyingpotential future changes in tropical cyclone frequency and intensity.The ability to detect such changes depends on a consistent and reliable global tropical cyclone dataset. Until recentlyno central repository for historical tropical cyclone data existed. To fill this need, the International Best TrackArchive for Climate Stewardship (IBTrACS) dataset was developed to collect all known global historical tropicalcyclone data into a single source for dissemination. With this dataset, a global examination of changes in tropicalcyclone frequency and intensity can be performed. Caveats apply to any historical tropical cyclone analysishowever, as the data contributed to the IBTrACS archive from various tropical cyclone warning centers is stillreplete with biases that may stem from operational changes, inhomogeneous monitoring programs, and timediscontinuities. A detailed discussion of the difficulties in detecting trends using tropical cyclone data can be foundin Landsea et al. 2006.The following sections use the IBTrACS dataset to show the global spatial variability of tropical cyclone frequencyand intensity. Analyses will show where the strongest storms typically occur, the regions with the highest numberof tropical cyclones per decade, and the locations of highest average maximum wind speeds. (PDF contains 3 pages)