Critique of Can We Detect Trends in Tropical Cyclones?

• Main Authors: Christopher W. L, Bruce A. Harper, Karl Hoarau, John A. Knaff
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Pacific; North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.512.4936; http://wcrp.ipsl.jussieu.fr/Documents/WOAP/Presentations/WOAP2D_7ReprocessingLandsea.pdf

recent upward trends in tropical cyclone activity are the spurious result of changes in the techniques by which tropical cyclones are detected. In particular, the Dvorak technique whereby tropical cyclone intensity is estimated from satellite imagery, has undergone several changes since its inception in the 1970s. It is important first to note that Landsea et al. offer no quantitative support for their hypothesis that the changes in Dvorak-based measurements; instead, they cite a few cases where independent measurements show that the earlier Dvorak-based measurements underestimated the intensity of storms. Such anecdotes hardly constitute a comprehensive argument and the authors fail to account for the fact that the Dvorak technique, when it first appeared, had been calibrated against aircraft-based measurements. During the entire evolution of Dvorak-based intensity estimation, independent, aircraft-based estimates were available in the North Atlantic region and, until 1987, in the western North Pacific. Although very little information is available about the calibration of the Dvorak technique, it hardly seems credible that forecasters would have applied it to new satellite data without at least spot checking it against aircraft data