The role of tropical waves in the genesis of Tropical Cyclone Seroja - one of the first tropical cyclones to significantly impact Indonesian land

Abstract

Tropical cylone Seroja was one of the first tropical cyclones to significantly impact Indonesian land and the strongest one in such close proximity to Timor Island. In April 2021 Seroja brought historic flooding to Indonesia and East Timor, as well as impacting Western Australia. Its genesis was associated with enhanced equatorial convection which was preceded by warm sea surface anomalies. This happened on the leading edge of a Madden-Julian Oscillation event. Within the Madden-Julian Oscillation, the interaction between convectively coupled equatorial Rossby wave and two convectively coupled Kelvin waves created "perfect storm" conditions and led to cyclogensis. The development and consequences of TC Seroja were unusual for this part of the world. The question arises: to what extent could such strong storms in Indonesia become more common due to the climate change? It is argued that looking at tropical waves in the warmer climates may provide some insight into this complex problem.

Accuracy Performance of Satellite-Derived Sea Surface Temperature Products for the Indonesian Seas

“…Even if atmospheric conditions are promising, TC will not develop if the SST is low (Lin et al, 2008) and difficult to occur in SSTs < 26 ºC (Emanuel, 2003). In the ocean region bordering the Indonesian seas, especially in the southeastern part of the tropical Indian Ocean, several TCs have occurred, such as Anggrek (October 31 -November 4, 2010), Bakung (December 10 -13, 2014), Cempaka (November 25 -27, 2017), Dahlia (November 27 -December 2, 2017), (Paterson, 2012;Gutro, 2014;Samodra et al, 2020;Yang et 2020;Aditya et al, 2021) and Seroja ; Latos et al, 2022). TC events can cause critical oceanic phenomena in the form of cooling SSTs (Hazelworth, 1968;Stramma, Cornillon and Price, 1986;Leipper, 1967;Lin et al, 2013).…”