Propagation of Upwelling on Western-Coast Sumatera During MJO Event

Yosafat Haryanto
2018 Journal of Ecological Engineering  
Upwelling is the movement of water masses over the surface of the sea that carry many nutrients and have a high primary fertility rate. Marine waters where upwelling occurs constitute a potential fishing ground because it is rich in nutrients (Ihsan, 2013). Upwelling is usually in the water depth range of 200-300 m (Bowden & Ferguson, 1980) , while Cole and Mcglade (1998) suggest that upwelling can also occur in shallow waters with a depth of 20-40 m. Bowden (1983) states that the seasonal
more » ... t the seasonal variations of upwelling occur with respect to the wind strength. ABSTRACT Madden-Julian oscillation (MJO) is an atmospheric oscillation due to atmospheric phenomenon that occurs due to the uniformity of solar energy received at the surface of the earth, MJO is a natural occurrence in the seaatmosphere system. When the MJO is active, in general there will be a disturbance in the upper air which is then followed by an anomaly at sea surface pressure causing the changes in the wind on the surface. The changes in the surface wind affect the sea surface currents which then cause the occurrence of coastal upwelling downwelling. The upwelling process itself is a process whereby a sea mass is pushed upward along the continent, when the beach is to the left of the wind direction, the ecological transport leads to the mass of water away from the coast. As a result, there is a mass vacuum (divergence) in the coastal area. This mass void will be filled by the mass of water from the inner layer that moves to the surface. Indonesian territory itself is passed by MJO in phases 3, 4 and 5, while for Sumatra region is passed by MJO phase 3 and 4. This research aims to identify the propagation of coastal upwelling during MJO on the west coast of Sumatera, therefore the data of geopotential height, surface pressure sea (MSLP), zonal and meridional components and sea surface temperature are used to analyze how the MJO effect on the coastal upwelling occurs in the research area. The analysis was conducted in June, July and August by comparing the atmospheric conditions at the time of strong MJO in phases 3 and 4 with normal viewing of anomaly geopotential height and MSLP and then seeing the anomaly surface wind changes from zonal wind (u) and meridional wind (v) and changes in SST in Sumatra region. The result shows that there is a change of GH and MSLP when MJO passes the west coast of Sumatra and then follows the change in the value of u and v and SST to identify the upwelling, while the anomaly change negative SST does not occur when MJO is active but has time lag (lag). In this analysis it was found that SST anomaly occurs when the anomaly changes in both the upper and surface water occurring after 5 days in phases 3, 4 and 5.
doi:10.12911/22998993/79420 fatcat:qrcrtyc5obaq5iwaiwerhnxr6i