Climate Change and Southern Hemisphere Tropical Cyclones International Initiative: Twenty Years of Successful Regional Cooperation

Abstract

Tropical cyclones (TCs) are the most dangerous weather phenomena to regularly affect countries in the Southern Hemisphere (SH). Historical records demonstrate significant inter-annual variability in TC frequency and spatial distribution of cyclone tracks; consequently, the year-to-year impact of TCs on countries varies. The El Niño-Southern Oscillation is one of the key global climate drivers which affects TC occurrences in the SH; however, there are other important large-scale environmental factors which contribute to inter-annual and intra-annual TC variability. Additionally, climate is changing on a global scale and it is important to understand how a warmer climate may affect TC activity. Since 1999 several academic, research and operational agencies from countries of the SH combined their efforts in improving our understanding of changes in regional TC activity due to natural variability and climate change, and established the “Climate Change and Southern Hemisphere Tropical Cyclones” International Initiative. The Initiative’s overarching strategy is to provide science-based information for enhancing TC early warning systems and assist with decision making in climate change adaptation and disaster risk reduction. As a result of these multi-national efforts, the first consolidated regional database of historical TC data for the SH (satellite-era, i.e. 1970 to present) was created; influence of global climate drivers on TC variability was investigated; a comprehensive TC climatology for the SH and skillful TC seasonal prediction models were developed. This publication highlights major achievements of this International Initiative over the past two decades. It also includes a brief description of the Tropical Cyclone Data Portal helping readers to learn quickly how to use this web-based information tool for examining historical TC activity over the regions of interests.