INFLUENCE OF DIPOLE MODE WITH RESPECT TO ZONAL WIND AND RAINFALL IN THE WEST SUMATERA : Abstract

• Main Author: Gusmira <br> NIM. 224 02 010, Eva
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/6082
• Institution: Institut Teknologi Bandung

</i><b>Abstract: <i></b><p align="justify"> Analysis of some climatic parameters is done in this research to investigate climate variability in the equatorial zone, specifically in West Sumatera by using the parameters of rainfall, zonal wind and sea surface temperature (SST). The analysis is done by using (i) analysis of rains characteristic in West Sumatera when Dipole Mode (DM) occurred, (ii) cross-correlation between Dipole Mode index (DMI) and precipitation and zonal wind for the DM years, (iii) analysis of composite SST anomaly and wind in West Sumatera and Indian Ocean for DM(-) and DM(+) years.<p align="justify"> Generally, it is found that DM phenomena have strong influence to the rainfall in West Sumatera, that is : when DM(+) the decrease of rainfall in West Sumatera occurred, while at DM(-) the increase of rainfall in West Sumatra occurred. Influence of DM is seen very clear at the period of JJA and SON which indicate that the occurrence of DM (-) cause the rain season earlier and DM (+) make the dry season longer so it results delays of the rains in West Sumatera. Drought condition in West Sumatera has strong correlation with DM(+) at dry season, when SST of the Indonesian region gets cold. Furthermore, correlation of DM to zonal wind in West Sumatera seen at surface wind, when DM(+), surface wind moving easterly by 3 m/s, and DM(-) moving westerly by 1 m/s. This phenomenon is not seen in the upper wind at 200 mb level.</p>