Miscellaneous. Cyclone frequency may rise over Indian coast from the warming of Pacific: study According to a study published in the journal Nature Communications Tropical cyclones that originate near the Equator have been devastating and are being unusually subdued in recent decades. The last major cyclone of this kind in India was Cyclone Okchi, which devastated parts of Kerala, Tamil Nadu and Sri Lanka in 2017. The Journal highlights that a phenomenon called Pacific Decadal Oscillation (PDO) are making such cyclones more frequent in the recent years. About Pacific Decadal Oscillation (PDO): PDO is a long-term ocean fluctuation of the Pacific Ocean, which lasts over a long time, approximately every 20 to 30 years. PDO is a pattern of Pacific climate variability similar to El Nino-Southern Oscillation (ENSO) in character, but which varies over a much longer time scale. PDO is not an annual occurrence. It corresponds to a warmer than average Western Pacific Ocean and relatively cooler Eastern Pacific but it happens over much longer time. Unlike an ENSO, a ‘positive’ or ‘warmer phase’ of a PDO can be known only after several years of measuring ocean temperatures and their interaction with the atmosphere.