The Indian Ocean has different characteristics from the Pacific and Atlantic Oceans because of the monsoon system. This system can cause continuous alterations in the direction of the Somali Current, the Indian Counter Current and the South Java Current (Hood et al., 2011; Susanto et al., 2001). At around 8°S in the Indian Ocean there is a westward flow, called the South Equatorial Current (SEC) with a velocity of less than 0.3 m s-1 and a shallow depth of less than 200 m (Quadfasel et al., 1996; Wyrtki, 1961). The output gate of Indonesian throughflow (ITF) is the source of the SEC in the Indian Ocean. The SEC achieves a high velocity in August with the formation of the Somali and Monsoon …show more content…
Although POM are appropriate means for elucidating the carbon cycle in water, currently there has been limited study about POM spatial distribution and its temporal variation (Hirose et al., 2011). The Eastern Indian Ocean which is affected by the South JC, ECC, ITF and Equatorial Jet (Tomczak and Godfrey, 1994; Hood et al., 2011), will cause spatial variation of POM due to water mass movement.
The nutrient contents of the Indian Ocean reflect addition and dissolution of organic matter, because there is no mixing occurs between major deep-water masses along flow paths (Piotrowski et al., 2009). The scarcity of the reactive nitrogen such as nitrate (NO3-) or ammonium (NH4 +) in the photic zone, limits the growth of phytoplankton in most (80%) world oceans located between 30 °N and 30 °S (Longhurst, 1998; Moore et al., 2013). In such regions (including E-WIN's study area), the level of biological activity is sustained by the upward mixing of NO3- from the deeper ocean. (Eppley and Peterson, …show more content…
Therefore, estimation of the total bacteria in the representative layers (e.g. mix, thermocline and deep), will be an important clue to estimate the remineralization potency in the Indian Ocean.
E-WIN as a contribution to IIOE-2
The Widya Nusantara Expedition (E-WIN), is one of the annual cruises which have been conducted since 2007 by the Research Center for Oceanography - Indonesian Institute of Sciences (LIPI). The goal of E-WIN 2015 is to determine the biogeochemical processes in the Eastern Indian Ocean regulated by the equatorial jet and Sumatran currents. Considering the Indian Ocean profile, this expedition included the following main aspects:
1. spatial variation of phisical factors of the Eastern Indian Ocean in correlation to the formation of the South Java current,
2. plankton dynamics and its role in