Spatial profiles of tropical cyclone track densities and temporal (or seasonal) profiles of tropical cyclone daily frequencies for the Southern Hemisphere and two sub-regions � the South Indian Ocean (west of 135�E) and the western South Pacific Ocean (east of 135�E) - have been analyzed. Average profiles have also been constructed for El Ni�o, La Ni�a and neutral years. The average annual number of tropical cyclones in the Southern Hemisphere is around 27; on average 16 tropical cyclones occur in the South Indian Ocean and 11 tropical cyclones occur in the South Pacific Ocean. The tropical cyclone season usually extends from November to April but occasionally early and late season cyclones occur. The tropical cyclone season reaches its greatest intensity during January, February and March with the average daily frequency between 1 and 2 cyclones. There is no apparent trend in occurrences of tropical cyclones in the Southern Hemisphere during the last three decades.

Tropical cyclone behavior in the South Pacific and the South Indian Oceans is influenced by the phases of the El Ni�o � Southern Oscillation phenomenon. Tropical cyclone activity in the South Pacific east of 165�W is higher during El Ni�o years than in La Ni�a and neutral years. Tropical cyclones increase in number between 70�E and 165�W during La Ni�a years in comparison with El Ni�o and neutral years. The maximum tropical cyclone frequency in the Southern Hemisphere during La Ni�a years occurs at the end of January, during El Ni�o years - at the end of February / beginning of March. The daily frequency of tropical cyclones, averaged across the season, is 30% higher in the South Indian Ocean than in the South Pacific. The tropical cyclone season for the South Indian Ocean starts a month earlier in La Ni�a and neutral years than in El Ni�o years. It is the opposite in the South Pacific Ocean: the tropical cyclone season starts a month earlier in El Ni�o years than in La Ni�a and neutral years.