Impact of cross equatorial northerly surge (CENS) on Jakarta heavy rainfall and its interaction with tropical cyclone (Case study: 18-25 February 2020)

Abstract

This study analyzed the causes of flooding in Jakarta area on 18-25 February 2020. Satellite-derived-meteorological parameters were used to elaborate the underlying cause. Convective cloud index derived from Himawari-8 satellite and horizontal precipitation distribution derived from Global Satellite Mapping of Precipitation (GSMaP) dataset, as product of Global Precipitation Measurement (GPM) satellite, confirmed heavy rainfall occurred during this period. The results showed that the floods during this period were atributable to the strengthening of the notherly surface wind from the South China Sea that cross the equator well known as Cross Equtorially Notherly Surge (CENS). This notherly surge brought abundant water vapor and produce intensive rainfall over north coast of West Java Island. Strengthening of notherly surface wind was represented by CENS index derived form surface wind data obtained from Cross-calibrated multi-platform (CCMP) wind vector analysis dataset. The presence notherly surge was accompanied by cold sea surface temperture (SST) in South China Sea shown by optimally-interpolated SST (OISST) dataset. In addition, this study highlighted the role of tropical cyclone (TC) Ferdinand, formed to the southeast of Java island, that supressed convective activity over Jakarta on 22-23 February as shown by minimum rainfall during active period of CENS.