Remote Sensing of Coastal Discharge of SE Sumatra (Indonesia)
The coastal discharge of Indonesia is driven by high precipitation throughout the year. Monsoon and tides form a highly variable dynamical system that satellite remote sensing is the only method to acquire synoptic information. The large rivers of SE-Sumatra belong to the major tropical carbon and sediment sources for the world ocean. Knowledge of carbon sources is important because of their potential impact on coastal ecosystems and on climate change. Drainage of peatlands enhances the concentration of dissolved organic matter (DOM) and strong tidal currents the suspended particulate matter (SPM) load in the rivers. The high concentrations strongly reduce the available light in the water column of coastal regions. The coloured part of DOM (CDOM) absorbs light in the short wavelength range. Measured very high absorptions changed the colour brownish that the tributaries belong to so-called black water rivers. High SPM concentrations made the water milky and bright. Different compositions of water constituents led to large variations of water colour, which made ocean colour remote sensing to the preferred method for investigating river discharge and coastal transport in different spatial and temporal scales. Sources of different water masses were identified, the estuarine turbidity maximum zone and the spreading of river water in relation to tidal phases were detected. The transport processes in adjacent Malacca and Karimata Straits are described in relation to monsoon phases and ENSO. In addition to available satellite derived level 2 products, CDOM and DOC charts were retrieved using regional algorithms derived from measurements.
KeywordsIndonesia South- East Sumatra Water constituents Ocean colour Remote sensing Coastal discharge Transport Processes Tidal and monsoon influence
The authors thank scientists and students of the University of Riau in Pekanbaru and crews of the vessels for the support during the cruises. MODIS data were received from NASA Rapid Response System and MERIS data from ESA. The study was funded by the Federal German Ministry for Education, Science, Research and Technology (Grand No. 03F0473E-IOW). The authors thank the editors and reviewers for the helpful comments and constructive hints.
- Doerffer R (2002) Protocols for the validation of MERIS water products, no. PO-TN-MEL-GS-0043. ESAGoogle Scholar
- Hendiarti N, Siegel H, Frederik MCG, Reissmann J, Andiastuti R (2006) Remote sensing investigation of coastal discharge of Siak estuary and nearby Jakarta Bay. In: Proceedings of the 16th APEC workshop on ocean models and information system for the APEC region. OMISAR Project Publication, Ho Chi Minh City, 2005, p 5Google Scholar
- Højerslev NK (1980) On the origin of yellow substances in marine environments, vol 42. Report Institute Physical Oceanography of University of Copenhagen, pp 39–56Google Scholar
- Lorenzen CJ, Jeffrey SW (1980) Determination of chlorophyll in seawater. UNESCO Techn Pap Mar Sci 35:20Google Scholar
- Namba T, Saadon MN (2001) Water characteristics of the Malacca Strait and the adjacent sea. In: International conference on international oceanographic data and information exchange in the Western Pacific (IODE-WESTPAC) 1999, Langkawi, MalaysiaGoogle Scholar
- Pang WC, Tkalich P (2003) Modeling tidal and monsoon driven currents in the Singapore Strait. Singap Marit Port J, 151–162Google Scholar
- Siegel H, Gerth M, Beckert M (1994) The variation of optical properties in the Baltic Sea and algorithms for the application of remote sensing data. SPIE, vol 2258. Ocean optics XII, pp 894–905Google Scholar
- Siegel H, Gerth M, Beckert M (1997) Variation of specific optical properties and their influence on measured and modelled spectral reflectances in the Baltic Sea. In: Ackleson SG, Frouin R (eds) Ocean optics XIII. Proceedings of the SPIE, vol 2963, pp 526–531Google Scholar
- Wyrtki K (1961) Physical oceanography of the Southeast Asian waters. Naga report 2. Scripps Institution of Oceanography, San DiegoGoogle Scholar