Science Source

Kerry Emanuel

American Meteorological Society

Published date April 4, 2007

Environmental Factors Affecting Tropical Cyclone Power Dissipation

Presents revised estimates of kinetic energy production by tropical cyclones in the Atlantic and western North Pacific
These show considerable variability on interannual-to-multidecadal time scales
Finds that, in the Atlantic, variability on time scales of a few years and more is strongly correlated with tropical Atlantic sea surface temperature, while in the western North Pacific, this correlation, while still present, is considerably weaker
Uses a combination of basic theory and empirical statistical analysis to show that much of the variability in both ocean basins can be explained by variations in potential intensity, low-level vorticity, and vertical wind shear
Finds that potential intensity variations are in turn factored into components related to variations in net surface radiation, thermodynamic efficiency, and average surface wind speed
Finds that, in the Atlantic, potential intensity, low-level vorticity, and vertical wind shear strongly covary and are also highly correlated with sea surface temperature, at least during the period in which reanalysis products are considered reliable
Finds that, in the Pacific, the three factors are not strongly correlated
Quantifies the relative contributions of the three factors