Extended Abstract (48K)3A.1
A look at global tropical cyclone activity with respect to the Atlantic change-point year of 1995
Mark A. Lander, University of Guam, Mangilao, Guam
During 1995, there was a near-record number of named tropical cyclones in the North Atlantic basin. This unusual event fueled speculation that it marked a tangible signal of global climate change, or that it marked a return to a period of higher tropical cyclone activity in the North Atlantic such as that which has been documented to have occurred during the decades of the 1940s through the 1960s. Less publicized, the tropical cyclone acitivity in other basins in 1995 was almost everywhere below normal. Since 1995, the North Atlantic basin has seen a striking increase in the annual number of tropical cyclones (except during the major El Nino year of 1997). In other basins -- particularly the western and eastern North Pacific -- the years since 1995 have seen a general decrease in tropical cyclone activity. The data suggest that interdecadal shifts of tropical cyclone climate are occurring in most basins; however, the breakpoint years between periods of enhanced tropical cyclone activity and decreased tropical cyclone activity differ among basins. For example: in the Atlantic, a period of generally below normal annual tropical cyclone counts occurred during 1972-94, with an upswing occurring in 1995 that continues today. In the western North Pacific, a period of generally below normal annual numbers of tropical cyclones occurred during 1973-1988, followed by an upswing of tropical cyclone acitivity during 1989-97. After 1997, the annual numbers of tropical cyclones in the western North Pacific decreased markedly, with the lull continuing today. This talk will describe the global tropical cyclone distribution of the past 40 years (e.g., annual counts and tropical cyclone genesis locations). In most basins, variations of tropical cyclone climate associated with ENSO are seen that are superimposed on longer-period changes.
Session 3A, Seasonal to Interannual Prediction and Predictability III (Parallel with Sessions 3B, 3C, & 3D)
Monday, 29 April 2002, 4:00 PM-5:30 PM
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