Modulation of global sea surface temperature on tropical cyclone rapid intensification frequency

Abstract

Rapid intensification (RI; ≥30 knots within 24 h) is an essential characteristic of a CAT 4–5 hurricane (≥115 knots). Between 1980 and 2018, interannual variability in CAT 4–5 hurricanes was strongly correlated with RI, both globally and in individual basins. The annual number of tropical cyclone RI events is a useful measure of global intense CAT 4–5 hurricanes. Here, singular value decomposition analysis was applied to sea surface temperature and the number of RI events throughout the world as calculated from best track data. The first two modes explained ~70% of the total covariance. The mode that dominated variability in global RI occurrence was primarily modulated by the El Niño southern oscillation and the Pacific decadal oscillation. The first mode indicated decreased RI activity in the North Atlantic and increased RI activity in the North Pacific except between 10°–30° N and 125°–135° E, and the corresponding sea surface temperature pattern matched the positive El Niño southern oscillation and Pacific decadal oscillation phases. For the second mode, RI occurrence increased in most parts of the active RI region though with some exceptions, and this was linked with global warming. These results suggest that interannul variability in TC RI events and the associated CAT 4–5 hurricanes are modulated by climate variability in the global scale.