Wind vector anomaly in the maritime continent of Indonesia: It’s impact on local climate in West Nusa Tenggara
Mahrup, Mansur Mashum

University of Mataram

Abstract

Monsoon is common in the maritime continent of Indonesia. However, anomaly of wind vector was inevitable to cause drought in eastern Indonesia. A descriptive research was conducted to identify locus of wind vector anomalies attributed to drought event in West Nusa Tenggara. There were 36 years (1983-2019) of global wind vectors used to localize locus of anomalies, and 15 year data of rainfall from 9 selected stations at Lombok and Sumbawa were collected. Both variables were statistically analyzed for dependence at ɑ 5%. Results showed that drought attributed to wind vector anomalies taking place at three sites, namely: in a convergent zone of South Indian Ocean at 105o-110oE and 8.5o-15oS; west coast of Sumatera at 95o-110oE and 5oN-5oS, and in Natuna’s sea at 105o-115oE and 5oN-10oN. A severe drought occurred when there was no wind entering the convergent zone, wind was heading west at the west coast of Sumatera, and to the east or north to Pacific Ocean at Natuna’s sea. Anomalies frequently occurred in November, December, and February. In conclusion, drought in West Nusa Tenggara associated with wind vector anomalies in the convergent zone, west coast of Sumatera and Natuna’s sea on the onset of rainy season in November to December, and a peak rainy season in February.

Keywords: drought, anomaly, maritime, convergent

Topic: Environmental Engineering