Science Source

A 66‐year tropical cyclone record for south‐east Africa: temporal trends in a global context

Investigates changes in the frequency and timing of tropical cyclone landfalls over the south‐west Indian Ocean during the last 66 years
States that little is known about the spatial and temporal trends of such storm landfalls during recent historical times, specifically the last ca. 100 years
Analyzes three storm track records spanning periods of 66–161 years
Establishes that much of the perceived change in storm numbers can be attributed to improvements in storm detection methods over the past century
Finds no statistically significant trends in the frequency of tropical cyclone landfalls over Madagascar and Mozambique over the past 6 decades, despite more comprehensive records during the most recent period
States, however, that there is considerable interannual variability in the number of storms making landfall over the countries investigated; most probably driven by cyclical atmospheric forcing, including El Niño‐Southern Oscillation (ENSO) and the Quasi‐Biennial Oscillation (QBO)
Concludes that recent trends indicate an increasing number of tropical cyclones tracking to the south of Madagascar, potentially associated with the southward shift of the 26 °C isotherm, combined with a decrease in the steering flow during La Niña years