My research goal is directed at the quantitative study of the oceanography of tropical region and its impact to larger scale climate system. The present research focus is on the exchange of water between the tropical Pacific and Indian Oceans known as Arlindo (Arus lintas Indonesia in Indonesian, meaning the Indonesian throughflow [ITF]). This topic is important for resolving the rather complex regional oceanography and the associated ecosystem and specifically for understanding the ENSO, Indian Ocean Dipole, and Asian-Australian Monsoon climate phenomena. The ITF is considered to be a key component in shaping the Pacific and Indian Ocean heat and freshwater budgets and climate phenomena responding through the resultant sea surface temperature patterns.
I have been working on Arlindo a joint project between Indonesia and the USA, In recent years, many successful ITF monitoring programs provided a first look at the variability of the ITF from its Pacific source region, through the internal seas, and out to the southeast Indian Ocean. However, these ITF measurement programs lacked of temporal coherence: the observational data cover different time periods and depths in the different passages of the complex pathways leading to the Indian Ocean. This has lead to ambiguity of the mean and variable nature of the ITF, and the transformation of the thermohaline and transport profiles within the interior seas. To remedy this and as continuation to the Arlindo program, we have a newly funded program known as INSTANT (International Nusantara and Stratification) a coordinated international effort involving contributions of 5 countries (USA, France, Netherlands, Australia, Indonesia). We have successfully deployed 11 moorings in the major inflow and outflow of ITF passages in Dec.03-Jan.04. The INSTANT objectives are: To determine the full depth velocity and property structure of the Throughflow and its associated heat and freshwater flux, To resolve the annual, seasonal, and intraseasonal characteristics of the ITF transport and property flux, To investigate the storage and modification of the ITF waters within the internal Indonesian seas, from their Pacific source characteristics to the ITF water exported into the Indian Ocean, and To contribute to the design of a cost-effective, long-term monitoring strategy for the ITF.
Currently I am working on analysis of sub-mesoscale features (the spatial scale is from 100m to 10km) in the Indonesian Seas. The main objective is to study generation mechanism, dynamics, evolution and propagation of sub-mesoscale features. The overall questions are: What is main driving force for the sub-mesoscale generation? What causes of the variability and evolution? Do the throughflow and monsoon systems affect the variability? The hypothesis is that variability of ITF and tidal current as well as complex geometry and bathymetry of the strait control generation mechanism, evolution, and propagation directions of the sub-mesoscale features (fronts, jets, eddies and internal waves).
Some of my projects include:
- SITE: South China Sea-Indonesian Seas Transport/Exchange
- Reconstructing tropical Pacific climate variability from ice core in Indonesia and Peru
- INSTANT: International Nusantara Stratification and Transport Program
- Sunda Strait Dynamics
- Interocean transport from satellite altimeter and ocean bottom pressure
- Analysis of Submesoscale in the Indonesian Seas
- Upwelling along the coast of Java and Sumatra and its relation to throughflow, climate phenomena and Productivity
- Indo-Pacific Sea level and Sea Surface Temperature Variability
- Climate impacts to fisheries and primary productivity variability in the Indonesia Seas