Climate change in The Lesser Sunda Islands: The harsh region in the maritim continent of Indonesia

Abstract

Abstract The Lesser Sunda islands, i.e. Bali, West and East Nusa Tenggara are locus of the harsh climate regime in Indonesia. The research was conducted in 2020 by a Descriptive method that aims to identify occurrence of climate change represented by anomalies of sea surface temperature (SST), air temperature, precipitation, and wind vector. The study area was focused on the convergence zone of the South Indian Ocean extending from 0° to 10°S, and 114° to 130°E. The temporal observation was at a peak of the rainy season in February and a transition period in March and April. Changes in climate variables were quantified by a test of two linear regression slopes and a binomial probability. Climate data were acquired from the International Research Institute (IRI) in a span of 30 years (1990 to 2020), with exception of air temperature from 1920 to 2020. Results showed that rainfall and SST had changed since 2005, and air temperature since 1995. Rainfall was significantly decreased afterward. SST and air temperature subsequently increased. The impact of climate change was compounded by wind vector anomalies in February, March and April. In conclusion, the Lesser Sunda Islands had experienced the ongoing climate change, indicated by lowering annual rainfall by 130.8 mm, increasing SST by 0.8°C and air temperature by 0.1°C in a decade respectively. In addition, Persistence Westerly winds through the end of April possibly induced severe flooding, on the other hand, the early emergence of southeast Trade winds before April could result in severe drought.