1. Sustained Monitoring in the Timor Passage, Ombai Strait and Australian NWS Susan Wijffels, Bernadette Sloyan, CSIRO Craig Steinberg, AIMS

2. INSTANT: A PROCESS STUDY 2003-2006
Total ITF 15 Sv
(1Sv = 106 m3 s-1)
Ombai and Timor Passage comprise >80% of ITF transport .
Gaps in INSTANT Outflow measurements
Sunda
Australian North West Shelf (very wide and shallow, but warm)

3. INSTANT: A PROCESS STUDY 2003-2006
Timor Strait – mean along strait flow

4. Timor Section in the BlueLink Reanalysis (10km)
Strongest EOFs
Mean
CSIRO. Insert presentation title, do not remove CSIRO from start of footer

5. INSTANT: A PROCESS STUDY 2003-2006
Ombai Strait – mean along strait flow

6. DESIGN
Cross shelf array extending across Timor Trench – all moorings located on Jason altimeter track
Ombai location – same as INSTANT S. Ombai/JADE Mooring site

7. IMOS ITF, Kimberley & Pilbara Array
A proposed moorings array for Northern Australia

8. DESIGN High tension moorings similar to INSTANT
Upward 150kHz or 300kHz ADCP
Downward 750kHz ADCP
Point TP (S) up to ~20-30m.
Point TPV (S) down to sill
Also deployed a PIES in Ombai Strait - could this help extrapolate temperature to the surface
Shelf array 6 months servicing schedule
Tall moorings 18 month servicing schedule

9. IMOS IndoFLOW MOORINGS
The Indonesian Throughflow array monitoring the Ombai Strait and Timor Passage was completed on 22 June 2011.
The Ombai and Timor Sill moorings are in 3000 – 3400 m, and the Timor North mooring is in 1114 m.

10. TIMOR South: Raw Current Profiles over 400m
Speed
Direction
Jul 2010
Oct 2010
Speed
Working with ABOS to provide ITF NW shelf component
Direction
Oct 2010
Dec 2010

11. IMOS IndoFLOW MOORINGS

12. IMOS IndoFLOW MOORINGS

13. IMOS IndoFLOW MOORINGS

14. IMOS IndoFLOW MOORINGS
Mooring deployments take between 3 to 5 hours. In Ombai Strait gas and cargo ships (approx 300m long) gave us room to drift onto the mooring site.

15. La Nina fresh cap
Comparison on 2011 and INSTANT Temperature, Salinity and Density profiles (0-200 m) in the Timor Passage

16. La Nina Fresh Cap

17. Salinity changes 1995-2003 1995 - CTD Oct 1999-Sep 2002

18. Predicted salinity change over the top 180 metres in the Indo-Australian Basin and observations
Change due to P-E
in Indo-Australian Basin
Change due to combined P-E of
Indo-Australian Basin and
Banda Sea (lagged by 1 year)
Predicted change = Vorig – (Vorig.Sorig + Vfresh.Sfresh) / (Vorig + Vfresh)
Vorig = 180 m3, Sorig = 34.5, Sfresh = 4
Phillips et al, GRL, 2005

19. CONCLUSIONS AND FUTURE DIRECTIONS
The Timor Passage and Ombai Strait are now monitored. This begin the long-term monitoring of the Indonesian Throughflow
Comparison of Upper Ocean temperature, salinity and density profiles between 2003 and 2011 show large variability in the mixed layer and subsurface. Freshening in surface layer the result of La Nina conditions.
The mooring time-series data (current, temperature and salinity) will be available via the IMOS data portal.
Working with international collaborators to have the Lombok Strait re-instrumented.

20. ACKNOWLEDGEMENTS

21. PLANS
1st turnaround of tall moorings on RV Southern Surveyor in September 2012
swath the cross-strait transect to the sidewalls
LADCP/CTD sections – sidewall boundary layer thickness (structure is a major source of error in net transport)
synthesis shelf/deep transects for full transport estimates
assess the use of the PIES (combined with satellite SST) in addressing near surface temperature gap

22. Issues / Opportunities
We can have the total outflow if we can instrument Lombok Strait – this question should be a focus of TT
Piggy back additional measurements on the cruises.
ACCESS/Synthesis
Can only happen if we follow the CLIVAR principles of free and open sharing of data
Can we put all CLIVAR ITF mooring data in one place (or links to the data from one place)??
aim for transport (volume,heat/unit depth) products for use by modeling community

23. ACKNOWLEDGEMENTS
We thank the Master and crew of the RV Solander for their outstanding cooperation and hard work during the voyage. John Leutchford provided invaluable assistance with pre-voyage planning and electronic, computer and vessel support during the voyage. We particularly thank Peter Doherty and Frank Tirendi (AIMS) for their assistance in facilitating the cruise and the government of Timor Leste for granting permission to carry out this research. Finally we thank Akasio Dos and Nelio Arnaldo, Timor Leste observers, for their assistance during the voyage. This cruise was sponsored by the Australian Integrated Marine Observing System, CSIRO and AIMS.