THE INFLUENCE OF LA NIÃA AND LA NIÃA MODOKI PHENOMENONS TO RAINFALL ANOMALIES IN THE ISLAND OF NEW GUINEA (CASE STUDY: DECEMBER 1990âNOVEMBER 2020)
Rainfall in a region is influenced by several factors, one of which is the interannual factor. Two examples of interannual factors that affect rainfall are La Niña and La Niña Modoki. Both La Niña and La Niña Modoki are theorized to cause increased rainfall in maritime continents, including Pa...
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| Format: | Final Project |
| Language: | Indonesia |
| Online Access: | https://digilib.itb.ac.id/gdl/view/87152 |
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| Institution: | Institut Teknologi Bandung |
| Language: | Indonesia |
| Summary: | Rainfall in a region is influenced by several factors, one of which is the interannual
factor. Two examples of interannual factors that affect rainfall are La Niña and La
Niña Modoki. Both La Niña and La Niña Modoki are theorized to cause increased
rainfall in maritime continents, including Papua Island. This study aims to compare
the impact of La Niña and La Niña Modoki on rainfall anomalies in Papua
throughout a climate period (December 1990–November 2020), and to explain the
moisture transport mechanisms that influence these conditions. The study was
grouped seasonally.
The data utilised were monthly precipitation from Climate Hazards Group InfraRed
Precipitation with Station (CHIRPS), equatorial Pacific sea surface temperature
from Hadley Centre's sea ice and sea surface temperature (HadISST) v1.1, Niño3
temperature from NOAA Physical Sciences Laboratory, and vertically integrated
water vapor flux from ECMWF Reanalysis Version 5 (ERA5) Monthly Averaged
Data on Single Levels.
The results of the study show that when La Niña or La Niña Modoki occurs, half of
Papua Island (the southern side) responds with positive rainfall anomalies and
above-normal rainfall characteristics, while the remaining half (the northern side)
responds with weak negative anomalies. This condition appears the strongest
during the June-July-August (JJA) season and continues until the September
October-November (SON) season, although it is somewhat weaker. The rainfall
anomaly during the December-January-February (DJF) event is weak. La Niña
Modoki during March-April-May (MAM) also causes positive anomalies like
during the SON season. Moisture transport towards the southern side of Papua
Island generally comes from the sea on east-southeastern side and enters the
southern side of the island. This is consistent with the distribution of positive
rainfall anomalies dominated by the southern region of the island. The rainfall
anomaly caused by the moisture transport during La Niña is stronger than during
La Niña Modoki. |
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