Equally important is the observation and collection of data on the sea currents, sea level height, water temperature, salinity and biological parameters. Their spatial and temporal variability need be investigated in order to understand their behavior.
The transport and variability of Arlindo is also important to be investigated as this current transport large amount of mass and heat from the Pacific to the Indian Ocean, and thus may influence the monsoon occurring between the Indian Ocean and the Indian Continent.
The occurrence of harmful algal bloom (HAB) in the archipelrgo is very much related to the enrichment of coastal water by the nutrients introduced by land drainage and by upwelling. Large areas of the archipelago need to be observed to detect and pinpoint the areas that will be most affected.
Following the condition required by the UN Convention on the Law of the Sea 1992, Indonesia has designed three sea lanes opened to International Commercial Navigation. They are: 1. The lane passing the Malaca Strait, Natuna Sea, South China Sea; 2. The lane passing the Lombok Strait, Makassar Strait, Sulawesi Sea, Pacific Ocean (alternatively: Sulu Sea); and 3. The lane passing the Sawu Sea, Ombai Strait (alternatively: Timor Sea), Banda Sea, Maluku Sea, Pacific Ocean. Because of the navigational and trade activity, these lanes are potentially may be polluted. The spread and variability of the pollution need be investigated especially those that may potentially affected the coastal people and their life.
The occurrence of severe domestic pollution have already been inprogress in the harbours of large cities like Jakarta, Surabaya, Medan and Makassar. The intensity and their temporal variability of these pollution need further monitoring.
Since most of the observation and collection of data for these studies requires coverage of large areas, the need of instrumentation mounted on sattelites is very obvious. Sattelites now can provide data on sea surface temperature, chlorophyll and plankton blooming, sea level height, windspeed, waves, outgoing long wave radiation, clouds, etc. All these data are the right kind that are highly in demand.
The effort of understanding and prediction of natural hazards can not be separated from those that are being carried out in other part of the world, because of their global connection and significance. Therefore international effort must be coordinated.
