Detection of dry season anomaly using radiosonde data during intensive observation period (IOP) in 2017

Rini Mariana S,Tri Handoko S,Ibnu Athoillah,Findy Renggono,Erwin Mulyana,Rahmawati Syahdiza,Jon Arifian,Yunus Subagyo S,Edvin Aldrian,Budi Harsoyo,R Haigh,F.A Ismail,L Comfort,A Hakam

doi:10.1051/matecconf/201822902008

Abstract

In the period between July - August 2017, Indonesia experiences drought which was caused by The Australian Monsoon wind. Radiosonde data obtained from launches conducted at the Palembang Meteorological Station during the IOP of 17 July - 16 August 2017 and those from cities that represents monsoon area (Pangkalpinang, Jakarta, and Surabaya) were also added to analyze the connection between Australian monsoon and precipitation in Indonesia. During IOP, the Australian Monsoon Index (AUSMI) is weaker than during normal conditions. Australian Monsoon index is normally around 6 m/s. Here, The Australian Monsoon Index chart shows a sinusoidal pattern in which during the peaks and troughs of the index there were drought anomalies in the aforementioned cities. In addition, medium to heavy rainfall also occurs during the Australian Monsoon index peaks and troughs. That conditions are affected by MJO and local influence. When MJO is a negative anomaly, AUSMI Index can be at peak or at the troughs. During the drought anomalies in all of the four cities, moisture profile at the surface to 6000-8000m is very wet (65-100%) with vertical wind profile dominated by the southeasterly-southerly direction.

Highlights

Indonesia’s location that lies within the tropics has the capacity to build and produce complex systems
Pangkalpinang, Jakarta and Surabaya are categorized as the monsoonal area with minimum rainfall occurring during the July-August period [5]. This theory was proven by Intensive Observation Program (IOP) data (Intensive Observation Period) obtained on 17 July - 16 August 2017 from Palembang, Pangkalpinang, Jakarta and Surabaya which shows a decrease in rainfall intensity during the period of observation
This paper shows drought anomalies when Australia Monsoon in Palembang, Pangkalpinang, Jakarta and Surabaya use Radiosonde data, rainfall data and Australian Monsoon Index (AUSMI) data

Summary

Introduction

Indonesia’s location that lies within the tropics has the capacity to build and produce complex systems. The winds of the Asian continent bring dry and cold air from the land but since it travelled a long way through the vast Pacific Ocean, the wind becomes moist and humid air which contains a lot of water vapour that drops in the Indonesian area which indicates the commencement of the rainy season. This cycle can be distinguished as the dry season and the wet season. This research goal is to detect dry anomalies during the Intensive Observation Program (IOP) activity in Palembang by using the Pangkalpinang, Jakarta and Surabaya radiosonde stations data as a comparison

The material and method

Results and discussion

Conclusion

Further suggestion